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There's pretty consistent talk of speed on the list and I like it as much as the next guy, but I thought the odd note of caution might save some of you from nerve wracking troubles I've run into over the years. Hope this doesn't strike you as borrowing trouble, but here goes:
1) After about 200,000 miles, I broke my left lower front A Arm. It was $$ to fix. The break happened on a twisty country road up by Big Bear in the mountains semi-near L.A.. Lucky for me it broke on an inward turn, not outward, or I might have gone hurtling down the original Randy Mantooth cliff. If this part breaks, the car basically loses a wheel support and skids to a halt on three wheels and the frame for a skid pad. Not fun. Think about this the next time you're doing 90 mph and extolling the virtues of the American V8. The motors are great, just be sure your suspension is up to the stresses and strains of that kind of duty.
2) At about 250,000 mile, I broke the right front lower A Arm. Little body damage, fixable. But this time I had a kind of warning. What I want you to know:
The key symptom: very "soft" or strange feeling steering when I knew the fluid was topped up and the rest of the system was solid. If you feel this, slow down, slowly in a straight line and come to a stop.
What was happening at 50mph, was the ball joint housing in the A Arm was in process of breaking. It didn't completely break until I was off the freeway and on a 25mph road, I guess God likes Oldsmobiles. Again the car slid to a halt on three legs and an impromptu frame skid.
3) One Christmas morning maybe about 275,000 miles or so, my retrofitted sway bar had tweaked the outer rear suspension arms enough to make one break and let the rear axle loose. Turns out the shop that put it in should have used some spacers between the bar and the suspension arm it was bolted to so as to avoid new stresses on old suspension pieces. I didn't sue, but sure was mad. The axle broke loose and the car slumped down on the remaining members. I was in the junkyard within two days. So now I'm looking for boxed rear control arms and new pieces if I can find 'em.
Key symptom: No warning at all, but I should have noticed that the sway bar was extra tight against the arm and bending it. Dumb on my part.
Message here is simple: Many of our cars are old. While new, or if low mileage, I guess you could still drive 'em at 120+mph. If you have high mileage, like mine, or if your car's been driven hard -- think twice about heading for the salt flats. The car may leave you stranded or worse.
Hope this isn't too much of a downer, just trying to save some of you from troubles I've had. Just the same, I ain't selling my old Olds.
Sure would love some tubular A arms and new control arms though.
Sorry to deliver the bad news, but happy to help you live safer. The upper arm bears far less weight and stress than the lowers, but if they go the result is essentially the same: you'll stop, perhaps suddenly, perhaps unpleasantly.
Losing the experience of these cars makes me unhappy too, but metal fatigue is real. I'm not sure it's real well understood by the engineering community. So as to head off the rare/expensive problem, start hoarding those parts now. I do.
Sorry to deliver bad news, but reality check ain't a bad thing once in a while. In a way it makes each mile you get out of your car that much better.
You can pull any A-Arms from 65-70 big cars. Not surprised about that ball joint stuff, mine broke at about 250k miles or so. Try to get a pair and note the mileage of the car you pull them from so you know how much they have on the clock. One other thing you can do is weld rebar into the inside edge of the outer side of the A, just around the balljoint to reinforce it. I did this and am happy. Also when you pull, if you have a choice, check out the bushings on the donor car, if they are cracked or worn you increase the chance of the A arm holes being out of round which will leave you with a clunking sound when you shift from reverse to drive or back again. The fix here is to tack weld the bushings to the arm. You can also tack weld the balljoint in place if you're worried about it.
Be sure to get this stuff safe, these cars are old and the suspension parts were not designed to last as long as we want them to (perpetually). If you can swing it, have the rears magnafluxed and checked while you're at it, they are likely to be as old as the front parts which broke.
[ Thanks for this information.]
1964, 1965 Short Boxed Rear Arms
A warning for 1964 and 1965 owners of Olds with boxed lower arms. Prior to '66 the boxed section (that is the plates on the bottom) did not extend all the way to the rear of the arm. It ended at the location of the back bolt that holds the sway bar. The arm can crack starting at the bottom and work it's way up the inside & ouside of the arm, eventually breaking. I caught my (past) '65 442 cracked half way up. Fully boxed arms '66 & up won't do this.
[ Thanks to Kurt Shubert for this information. ]
Basically, suspension systems are designed to function with certain types of motion through the built-in pivot points and flexures of the system. Any distortions of the suspension at points other than the intended pivot points (as in, flexing of the control arms) has a detrimental effect on both handling and traction. Stiffening the suspension and chassis structural members will always benefit the car by allowing the system to work more like it was designed to work. Note that I use the term stiffening as opposed to strengthening, as the issue isn't the ultimate strength of the components but their ability to resist unintended bending and deflections (although I find this is the same sort of loosing argument as trying to correct people who say a car is "fast" when they mean "quick").
Note also that I'm not referring to stiffening the springs or shocks, but the structural elements like the control arms and frame attach points. Now, stiffening springs or sway bars will often serve to mitigate some unintended deflection by limiting suspension travel to a point that these structural components don't have a chance to deflect. Note that this same phenomena also helps cover us a less-than-optimum suspension geometry by not allowing the suspension to deflect enough to reach the point in the travel where the geometry gets bad. While this does improve handling, it is not necessarily the preferred solution. Stiffer springs can cause the tires to loose full contact with the road surface on less than smooth roadways. Unfortunately, even the best tires in the world have a difficult time generating grip when not in contact with the asphalt.
As a rule of thumb, American cars in general and A-bodies in particular are set up to understeer. As another rule of thumb, the stiffer end of the car (as in roll stiffness) will break away first. If you stiffen the front more than the back, you will increase understeer (not a good thing).
The term handling seems to be about the most subjective of all vehicle performance descriptions. Perhaps this is because of the lack of availability of skid pads and related test equipment for actual numbers comparison. Or a road course at ones disposal to compare modifications to lap times. Another reason the term is somewhat ambiguous, is that handling seems to have different meanings to different people. As an example, to some, good handling means easy to parallel park (I kid you not). We've all seen the Saturn ads where the gleeful owner exclaims how well it handles. Now, I've driven a Saturn, and good handling is not an adjective I would use to describe one.
Ultimately how a car handles with a particular driver is not only a function of the objective setup of the suspension but also a function of how "secure" and "in control" a specific driver feels when driving this car. As an example, many drivers would not feel very secure when driving a car which oversteers easily, with the result that while the car might be faster around a racetrack with a specific driver, another driver, feeling less secure, would not drive the car nearly as fast. For this second driver, a less-oversteering setup, while not as fast around the circuit at the limit, would provide a "better handling" car which would allow this second driver to go faster.
The term good handling also depends on the type of roads the car is driven on. If the vast majority of the roads where one lives are based on standard "L" shaped block corners, it would be very difficult to measure a cars potential and limits. Whereas, if you live in an area with lots of twisty roads and switch backs, you develop a different meaning of the term good handling.
The condition of the roads will also play a part here. A car with a rock hard suspension will perform better on a groomed race course than it will on a typical street with ruts, dips, patches, repairs, etc. A good handling street car must address the roads shortcomings in their suspension setup.
Driving style probably plays the largest role in an individuals definition of what is good handling. If one is into pushing the limits of adhesion on corners they will have a very different view of good handling than someone who is more straight line oriented or considers L shaped blocks to be corners.
[ Thanks to Joe Padavano, for this information. ]
Effects of Differential Type
Posi sends power to both wheels equally, (not computer controlled traction control setups). Torque causes right rear to lift, hence it's spins more then left, with an open differential. With posi, the left wheel will still have more weight on it then right wheel. An old trick is to lower the right side of car, or stronger spring on right side, or more air in air bag on right side. Since the right rear will lift, slightly more air in the right side bag works against the lifting, in effect equaling the right to the left.
Also, you can lower the left front of car, also to offset torque. Car will go much straighter off starting line.
Axiom, front engined, rear wheel drive cars, engine torque lifts front left side of vehicle, driveshaft torque lifts right rear wheel of car, so right rear of car lifts.
On slippery surfaces Posi is great-as long as your going in a straight line, but, on curves a open rear end will provide more stability then a Posi because one wheel will not be spinning, and hence will provide sideways stability.
[ Thanks to Lou Biggs for this information. ]
Roll CenterRoll Center is the point around which the body of a car is rotating when cornering. The rear suspension has its own roll center and the front suspension has its own roll center. A line drawn between these two points determines the roll axis. With double A-arm front suspensions, like the A and F bodied GMs, a roll center above ground will provide better handling. Not only does the roll center determine the rotational axis of the body, it is also the point at which the car's sprung weight is transferred to to the outside unsprung weight in a turn. Having the roll center above ground isn't just an GM A-body advantage, its an advantage (and a requirement) for any high performance handling vehicle.
To find the roll center, take one side of the front suspension, draw two lines: one line should intersect the upper control arm's ball joint and the upper control arm's inboard rotational shaft center. The second line should intersect the same points on the lower control arm. You have just drawn lines describing the angles of the control arms. On a stock 64-72 A-body, these lines will intersect on the outside of the car (the upper control arm points down and the lower control arm's angle is more or less horizontal). Now draw a line from the point determined by the centerline of the tire and the ground (the center of where the tire touches the ground), continue this line to the point of the intersection of your two control arm lines (this is called the intantaneous center). Continue this same line so it intersects the centerline of the automobile (this same line should intersect the instantaneous center point, the center of the tire patch, and the centerline of the vehicle. Where this line intersects the centerline of the vehicle is the Roll Center! A-bodies have a roll center below ground level (bad). The F-body knuckle is 1¼" taller than the A-bodies, so the angle of the upper control arm is changed (now it points upward, and the Roll center is moved above ground.
[ Thanks to Doug Ahern for this information ]
As a humerous aside to the understeer/oversteer inquiries: Understeer is when the driver is scared, Oversteer is when the passenger is scared.
Understeer is when the car turns less than you expect. Oversteer is when the car turns more than you expect.
What is it that gives you expectations, and why does the car not meet the expectations you have built up? At low power, like driving at 30 mph in turning the steering wheel a few degrees with neutral throttle, a car reacts linearly. Turn the steering wheel 20 degrees, and the car's path changes by X degrees. Turn the wheel 40 degrees, and the car's path changes by 2X degrees. This type of behavior makes up 99% of the driving experience of 99% of the population. This is our collective expectation, built up through driving cars and using all sorts of other linear devices.
This type of automobile behavior is engineered into cars and hides the true, non-linear nature of the car's systems, primarily traction and kinetic energy. Traction is non-linear with force: it is asymtotal with a bump that crosses the limit in the middle of the graph. Kinetic energy is quadratic with speed. Turning, the cross product of these, is a strange beast.
80 years of driving experience has shown the automakers that it is best not to expose the driving public to really weird behavior. The result is that, at the limit, cars are designed to be less and less responsive to steering wheel input. They are designed to understeer.
Of course racing, and high-performance driving in general, is done near the limit. So the driving enthusiast has to work to undo the car maker's built-in understeer by changing suspension components. The danger is that oversteer may be introduced.
Oversteer is the opposite condition from understeer, where the car responds to small steering wheel inputs with large changes in direction. Oversteer is an unstable condition, and almost always undesirable.
I can give you an example of fun/dangerous FWD oversteer/understeer. I put a few hundred thousand miles on a series of old Ford Fiestas. These were typical early '80s cars with typical built-in understeer.
My route to work passed through a rotary that had a uphill exit to a highway. After a few years of driving it, I would come in to the rotary at high speed, aiming for the exit. Under WOT, the car would understeer dramatically, sliding out of the rotary onto the exit. Easy as pie.
I altered the car to change the handling. A 20mm bar was put on the back and I changed from 155/12 to 175/13 tires. Then I ran over a deer at high speed and bent the rear axle tube, adding negative camber. On dry road, the car would stick much better.
When that rotary got wet, the driving was very tricky. On entry I would understeer as before, but at a higher speed. The exit was much more difficult. My changes had induced "lift throttle oversteer", something easy to provoke in FWD cars. At a particular spot in the rotary, I would ease up on the gas just a bit and pull the wheel right, and then get back on the gas. The car would snap violently from sliding in one direction to sliding in the other direction. Strong, strong oversteer, with the car reacting much more than the steering wheel input would imply. Ok in this condition, as it allowed me to fly through that series of turns, even in the wet. Failing to get back on the gas would have resulted in a spin, a classic symtom of oversteer.
See Paul Ferere's book Sports Car and Competition Driving.
[ Thanks to Frank Evan Perdicaro for this information. ]
One suggestion I would make is that you get your springs and sway-bars from the same source. The reason is that the degree of understeer/oversteer of your car is determined by the total roll stiffness at each end of the car, which is determined by both the springs and the sway-bars. Each company has a different idea of the best combination. Relatively soft springs work best with a stiffer sway-bar (this is HO Racing's approach), while stiffer springs match better with thinner sway-bars (Hotchkis, Global West). If you bought stiff springs from one source and stiff sway-bars from another the combination might not be optimal. Most likely it would still improve the handling, but not as much as possible. In the worst case you would have oversteer and a scary and maybe dangerous car to drive (stiff rear springs with a stiff rear sway-bar could do this). Also, you can't go only by the sway-bar diameter, the metallurgy of the bar and the length of the lever-arms at its ends will affect its torsional stiffness.
[ Thanks to John Carri for this information. ]
As a point of information, GM went to a common front suspension design on most of it's cars in the mid-70s, so that the 1973-up A/G body cars, the second gen F body cars, and the B body cars all use the same upper and lower ball joints. If I recall, somewhere in the late 80s there was a changeover to metric, however.
[ Thanks to Joe Padavano for this information. ]
F41 Factory Option
This is from my factory literature for the $41(!) F41 option.
Level II Firm Ride and Handling Suspension System, Includes: Firm Ride Front and Rear Shock Absorbers, Higher Rate Front and Rear Springs, Larger Front Stabilizer Bar (1.25 in. Diameter), Rear Stabilizer Bar (.875 in. Diameter) and Special Steering Gear 12.70:1 Steering Ratio.
[ Thanks to Mark Tupper for this information. ]
WS6 F-Body Option
The WS6 option consisted of Four wheel disc brakes with rear discs being 11.1", stiffer rear springs (25lb/in. higher deflection rating), stiffer rear shackle bushings, lower control arm supports, .75" rear stabilizer bar, polyurethane link bushings, tighter valved shocks, 14:1 constant ratio steering box, and a 1.25 front sway bar.
[ Thanks to Jason Labay for this information. ]
1964 - 1972 A-Body Information
For those of us interested in good handling from our Oldsmobiles, I have bad news. I hesitated a while before posting this because it is depressing. But after all, knowledge is always worth something whether or not its something one wants to hear, so here it is:
A well-designed front suspension for a car should keep the tires almost upright on the ground, even in hard cornering; it should keep the castor and toe angles virtually constant. The toe is designed to change slightly when the steering wheel is turned far to one side (called Ackerman geometry) but this is a small effect, and it should make the tires go from a small amount of toe-in to a small amount of toe-out when the turned all the way to either side.
Most folks on this list already know that the GM A-body front suspension doesn't keep the tires upright during hard cornering - rather it lets the tops of the tires tip outwards (camber change with suspension travel). Some creative soul figured out that the swap to a taller B-body spindle improves this particular problem.
About a month ago, while I was working on my '72 Supreme's front end, I realised that the lower control arms pivot on an axis that is inclined with respect to the car. This means that the tips of the lower control arm move back and forth as the arm moves up and down. That in turn moves the bottom of the spindle back and forth - which means that the *castor*, too, changes with suspension travel! This is built into the design of the car and cannot easily be changed, so those of us who want our cars to handle have to grin and bear it, as nothing can be done to fix it.
This weekend I was replacing the centre-link and tie-rod ends on my car, when I noticed more disturbing design features. First of all, the idler and pitman arms pivot at their front end, so that as they swing towards either side they pull the centre-link mounted to them slightly forwards as well as sideways. On other cars I've worked on (mostly Mopars), the steering arms on the front spindles also point backwards from the ball-joints, so that their tips follow almost the same arc as the pitman and idler arm. This means that the tie-rod ends stay almost parallel with the centre-link as the steering is turned from side to side. All well and good so far. Unfortunately on my car, and therefore on other GM A-bodies, the steering arms on the front spindles point *forwards*, pivoting about their rear end. This means that when the steering is turned to one side, the idler and pitman arm pull the centre link *forwards*, while the steering arms want to pull the outer tie-rod end *backwards*. So the tie-rod ends have to pull to an angle from the centre-link. That in turn will shorten the total distance from one outer tie-rod end to the other - meaning the front tires will toe-in more as the steering is turned to one side! This is just the opposite of what Ackerman geometry should do, and this will make our cars plow and understeer in hard turns. Sigh.
There is still more bad news. While replacing the centre-link I also noticed that it is not symmetrical in shape - it seems to be designed so that the passengers-side tie-rod pair has to be adjusted longer than the other. On my car, the passenger side tie-rod ends were adjusted to 18 7/8", while the drivers side was only 18" long. I tracked this assymmetry down to the fact that the idler arm mounts closer to the passenger-side framerail than the pitman arm mounts to the drivers-side framerail, because of the thickness of the steering gearbox.
What does this assymmetry mean? Your left front wheel and right front wheel won't turn through the same angle when you turn the steering wheel to either side.
So my poor Cutlass is burdened with a suspension in which all three of the important suspension angles - castor, camber, and toe - change in ways that are bad for handling as the suspension moves through its travel. Deep sigh.
Sigh, once more. I guess that even after I finish putting in the tall spindles and big brakes on my Supreme, even though I already have Hotchkis springs, KYB shocks, poly bushings, a 1 1/4" front sway bar, and 225/60/16 tires on 16x8 rims, it will still handle poorly compared to other cars with better designed suspension geometry.
It is interesting that the things I like about my Olds - its styling, its trustworthy engine, etc - are all purely Olds; the things I dislike, like the limp and floppy frame and the rotten front suspension design, are all purely generic GM designs! Maybe Oldsmobile got all the good engineers, and the ones who drooled out of the corners of their mouths and fell over things were set to designing the generic GM stuff.
The A bodies from at least 1968 to 1972 (my personal experiences) came with a "positive camber roll" front suspension design. What this means is that as the wheel moves upward it transitions into positive camber so at full suspension compression the tires would look like this: \ /. Also when the suspension fully extends it will also transition to positive camber so when the suspension is fully unloaded it will look like the same. The thing is that it isn't that noticable since the bump stops keep the suspension from extenting but so far.
What it sounds like the previous owner did was to give you what the refer to as a negative roll kit. I did this to my 1972 and plan on doing it to my 1968 but couldn't figure out a way to do it without buying an expensive conversion kit, never thought of using the later control arms. The later model spindles are one piece while all factory spindles up to 1972 were two pieces (upright and crosspiece that bolted together). These spindles were common to many GM cars including A, B, F, and X bodies during the mid to late 70's at least. The spindle has better rotor/ caliper (parts still easy to find), more strength, and is taller.
Being taller it changes the front end geometry so that the roll center moves from about an inch below ground to a couple inches above ground. It also makes the car transition into negative camber on compression and extension: / \. It is more noticable in extension, since due to the taller spindle the suspension will extend further before it hits the suspension stops since this stop is under the upper control arm which has been moved higher relative to the rest of the suspension. (on my 72 I would have to jack the car up about a foot before the tires would come off the ground!) If you've ever pushed your car hard in the corners and noticed how it sort of plowed and rounded off the outside edge (sometimes sidewall too) of the tire, that is because of the positive camber of the suspension as the car leans in the turn and the tire folds under. With the better roll center and the negative camber in the turn the suspension counteracts the tires tendancy to fold under.
The only drawback is that on some cars that have a lot of frame spread you have to use a lot of shims on the upper control arm to get the suspension to lign up. This can be a problem if your running a big block but your running a 350 and that's what I had in my 1972 with headers and it wasn't really even close. I think my largest shim pack after the alignment was 1/2 to 3/4". All in all it is a great setup but I highly recommend spending the $50 for an adjustable proportioning valve to balance the brakes properly.
I can't argue that the A-body front suspension geometry is less than ideal, but keep in mind that everything is a tradeoff. Some handling sacrifices have to be made for ride comfort and manufacturing cost/ease. The angled lower arm hinge line is designed to allow the wheel to move rearward as well as upward when going over a bump. This takes some of the jarring "sharpness" off of a bump, helping ride quality and actually helping to keep the tire in contact with the road. Remember that the best suspension geometry in the world is worthless if there's daylight between the tire and the tarmac.
Also, I think you may be giving the center link design a bum rap. Since the pitman arm on the steering box is closer to the centerline of the car than the idler arm, the center link would have to be asymmetric to keep the inner tie rod ends at the same distance from the center of the car. The pitman arm-center link-idler arm-frame all form a four-bar link with parallel sides, so this asymmetry shouldn't change the arcs that the inner tie rod ends follow as you sweep through the range of steering motion.
What the "A" Body GM frames have is typically called a "front-steer" front suspension. The design can be made to work, but as is with anything performance-oriented, speed costs money, how fast do you want to go (or how well do you want to handle)?
As for the Ackermann correction, part of it can be accomplished by changing the length of the steering arm, provided the steering arm can be removed and replaced. Almost any aftermarket spindle will have a removable steering arm, and they can work with any front brake system available.
The pitman arm's location can be changed (moved farther inboard) with spacers and the center drag link replaced with a shorter model, and the mounting holes for the tie rods can be moved by welding new mounts on the drag link.
If you replace the outer tie rods and adjusting sleeves with heim joints and longer sleeves, you can buy studs that mount in the outer tie rod holes on the steering arm, and shim the heim joint to do more correction.
A way to compensate for the camber change would be to replace the upper a-arm mount with a racing unit (properly braced) and angle it so the upper arm follows the same travel of the lower arm.
Finally, if you REALLY want to spend money, you could have a rack-and-pinion unit custom-mounted to the front frame. You could have the entire front suspension cut off and "stub" the front end so you could relocate the entire front suspension to a better geometry.
I could go on and on, but I'm sure you're getting the idea. How do I know all this? Right now, the winds of change are blowing real hard around here and it looks like Grace's racing plans are caught up in them. We did a LOT to the front suspension when we were planning to return to "roundy-round" (as Dave Smith calls it) racing, and now we'll be doing even more. If you're interested in what's been done so far, stop by our web pages, and click "Picture Archive" on the navigation map, or type in this: http://members.aol.com/ks7racing/archive1.htm and once you're there, look at the pictures of Grace after returning from the race shop.
Put the front end of your A-body up on jackstands. Now that the wheels are at full droop, note how the tops of the tires lean in towards each other (lots of negative camber). Now put a jack under one lower control arm and slowly jack it upwards. Watch the tyre/wheel as you do this, you will see the tire go from leaning inwards at the top all the way to leaning outwards at the top as you jack the control arm up through its range of travel. That change prevents the tire from staying flat on the road and gripping with all its tread width - this is an extreme example of camber change with suspension travel and it is not good suspension geometry, it is absolutely horrible suspension geometry! On any well-engineered suspension this camber change should be undetectable by eye, it takes a camber gauge to measure it on any of the Mopar's I've owned, for instance.
An even quicker and easier way to see the poor camber curve on the GM A-bodies is to get a buddy to drive one over a speed-bump and watch the camber angle on the wheel/tire as it goes over the bump. This is how I first noticed how bad the geometry is! You can see the tops of the tires lean outwards as the speed bump pushes the suspension up into the wheelwells.
When you go into a turn with a GM A-body the outside front tire does more of the work than any of the other three tires (the weight transfers to the outer two tires, so the inner two are lightly loaded and don't do much work; also these cars carry more than half their weight on the front wheels so it is the outside front tire that provides a majority of the grip needed to make the turn) and this is the very tire that is being tipped over by the camber change, reducing its grip at the very moment it is being asked to provide all it can. To get maximum lateral grip the tire MUST be flat on the road or have very slight negative camber, and that is the reason for all the interest in re-engineering the front suspension on these cars using taller spindles, etc.
Check out Fred Puhn's How to make your car handle or another book called Performance Handling - performance techniques for the '90's, whose author I don't remember, for lots of info on what makes a suspension good or bad. See "Knuckle Sandwich" by Marlan Davis, in June 1987 "Hot Rod".
[ Thanks to John Carri, Doug Ahern, Joe Padavano, Ken Snyder, Mike Bloomer for this information. ]
1964-72 vs 1973-77 A-Body Information
First off the poor geometry on the 1972 and earlier cars is in the front end. These parts will most definately not interchange as they have different locating points on the frame. The upper arms specifically are much wider across the bushings and the center to center distance for the studs is correspondingly longer also. The spindles will work with a few mods which is the way to correct the front geometry on the early A bodies. To make them fit you either need a set of ball joints with the lowers turned down to fit in the early lower control arm or have the spindles reamed for the earlier B.J.'s.
As far as rear arms go, I'm not sure they would work as I think they sit at different angles. You would have to take a few measurments as to bushing center to center, bushing width, and bolt diameter. If I'm correct about the arms sitting at different angles, then the rear sway bar will not fit. The front will work with some work but that's a whole other thread.
Here's what I know about the 1964-72 "A"-Body chassis, and this is from first- hand experience this time since Grace is a 71 Cutlass (no more coil case ground stories here.....)
1) The "A"-Body frame is more desirable than the 1973 - 77 frame in classes where you would have to use the stock lower control arms and could replace the upper control arms with tubular arms and relocated upper mounts, such as an IMCA-style modified. These cars use the frame to just in front of where the lower control arms for the rear suspension would be mounted. The 1973-77's are wider, but are heavier and people would rather have light weight than the extra width (which is desirable in itself). There's a company in Walker, Missouri (Dirt Works) that builds an IMCA Modified chassis with the "A"-Body frames. Now some are now beginning to build Modifieds with the "Metric" "A/G"-Body frames, but most contend these are "throw-away" cars, ones that are junked after significant damage, where an older frame would be repaired. There are always the odd-ball frame combinations out there (we had one that was made from a 1973 Impala frame!) but this is the typical situation around here.
2) Although I'd agree with the facts that the 1970-72 disc brake spindles are getting too hard to find, the fact that they are two-piece is more of an asset in our applications. In our situation, we could replace the arm with a different one for Ackerman adjustment. Before they allowed aftermarket spindles, the ones to use were from a 1968-69 Catalina with disc brakes. These also had a replaceable steering arm, and a higher spindle level effectively lowering the car's front end. The 1973-77 "A"-Body spindles are not adjustable for Ackerman due to their one-piece construction.
For those who don't know what Ackerman is, it's the difference that one wheel turns in respect to the other. Believe me, people spend a lot of time adjusting Ackerman on their cars here, Lakeside Speedway (1/2 mile asphalt oval) is known for demanding that the car's suspension be set up as close to ideal as possible for the best lap times.
I'll be able to answer more questions about the front suspension after we get Grace done and get out to the track for some real-time testing. Against the cookie-cutter late-model Monte's, T-Birds and GP's we'll really stand out!
We have some in-progress pictures posted online, go to http://members.aol.com/ks7racing/index.htm and click on the Picture Archive icon in the imagemap for more info on what we're doing.
The 1973-up A-body cars use ball joints with different tapers than those on the 1964-72 cars. In fact, GM went to a common ball joint size, with the 1970-81 F-body, the 1973-up A/G body, and the 1977-up B-body cars all using the same ball joints top and bottom.
The calipers will interchange onto a 1969-72 A-body, but that's about it.
A 1968-1972 rear anti-roll bar mounts between the rear lower control arms, the bolts go in horizontally.
A 1973-1977 rear anti-roll bar mounts more or less under the rear lower control arms, rather than in between them. The bolt holes point upwards, rather than sideways.
I'm fairly sure the stock 1972 and 1973 swaybars don't interchange. I know that they mount differently, but I've read that you can use the 73 bar on the 1972 if you use 1973 control arms on the 1972. I saw this in Car Craft, and I've never matched this up myself, so I could be wrong.
[ Thanks to Mike Bloomer, Ken Snyder, Joe Padavano, John Carri, Donovan DrkSole96@aol.com for this information. ]
Mid 1980's Cutlass':
The mid-eighties G-bodies have the outer sleeve STAKED in the LOWER control arms, so keep this in mind when replacing these types. Technically, I suppose "flared" would be more appropriate. The factory used a flaring type tool to ensure the lower a-arm bushings didn't pop out. Why, I don't know. But if they were replaced once, then whoever did it may not have "flared" the ends as instructed in the service manual. Or, the bozo at the factory just didn't do it, so who knows?
[ Thanks to Mick for this information. ]
Regarding GM A body spring interchangability, the differences and interchangability of the front and rear spings are:
- 1964 to 1967 front springs have a different cup diameter that than of the springs used on 1968 to 1972's.
- 1964 to 1966 rear sprints are pigtailed (turned inward toward the spring's cup center) only on one end, whereas the 67-72's are pigtailed on both ends.
[ Thanks to Doug Ahern for this information ]
Unfortunately, no one component alone, does not govern the handling of the car. For example, sway bar size. Tires, wheel size, spring rate, and bushing stiffness all enter into the equation. As a result, it is difficult to provide a general rule as to which bars to use on your car. Your best bet would be to go to one vendor (like PST) and get a complete package (bars, springs, bushings) and use their tire and wheel recommendations. I realize this is expensive to undertake all at once, but consider buying the components a little at a time. Start with wheels and tires, add springs and bushings, and then get the bars. Be careful, however, as the one thing you don't want to do is mismatch the sway bars. For example, one thing you don't want to do is add an 1 3/8 front bar with no back bar, as this has the potential for the car understeer dramatically.
On street cars, handling improvements can be made with quality shocks, stiff springs, beefier anti-sway bars, and faster ratio steering boxes. These kind of improvements along with rubber bushings and new ball joints and tie rod ends can improve handling and still protect your car's frame from stress fractures (extremely unwanted).
If the primary use of the car is a sunny day cruiser, and your main concern is to reduce the understeer and porpoising (sp?) effect, while retaining a reasonable level of ride comfort, this can be easily accomplished. First step, install a set of KYB Gas-A-Just shocks. Unlike a Monroe, etc. type gas shock, KYB's Gas-A-Just series are a high pressure gas shock designed for "spirited" driving. Whereas the Monroes, etc. are designed for more of a Cadillac type ride. For the price, it's hard to beat the KYB's performance. Next step. Install a rear sway bar. Even a factory bar will provide a fairly neutral condition with the small block. You will be amazed at the difference this simple bolt-on will make. At this point, I would add urethane frame and link pin bushings to the stock front bar. Go out and "test" the car. If you are still unhappy, the next step would be to add 4-4-2 rear springs. If it still understeers more than you desire, change out the factory rear sway bar with an aftermarket one.
Of course any modifications will in effect be a Band-Aid fix if the steering and suspension components are worn out. If a suspension rebuild is necessary, I would suggest NOT using urethane bushings. (I just put on my fire jacket in anticipation of the flames and hate mail). It has been my experience that the hard bushings will provide a very harsh ride. And in hard cornering situations on the street (with ruts, bumps, pothole patches, etc.) the car will have a tendency to skip over the surface imperfections, resulting in a loss of contact between the tire and the pavement. In other words, reduced handling abilities. Tires are also a key element in the vehicles cornering abilities. A 70 series tire sidewall will deflect much more in cornering than a 60 or 50 series will. Although the tradeoff is a harsher ride the closer you get to the rubber band type profiles. Tire pressures also have a significant effect on oversteer/understeer (And are often overlooked on street cars). To reduce understeer, increase the pressure in the fronts and lower it in the rears. Well, I hope this helps provide you with a starting point for reducing understeer.
My next suggestion would be the bolt-on route. Swaybars and shocks. If your gonna beat on the car, get Koni's - lifetime warrantee, and from club racer friends I can tell you its a no hassle warrantee. For swaybars try Addco (sp?) on the low end and Moroso on the high end. Moroso sway bars have solid end links, very good response (they are developed by Herb Adams VSE). Addco are repackaged by a lot of places - like Global West.
When you modify the suspension, decide what the part should do (ie springs hold up the car - bushings allow control arm to pivot etc.) and make sure your modes don't go against this. If you put ultra stiff bushings in the rear control arms - what's gonna give? Either you loose traction, or something that wasn't supposed to flex will (lets hope it doesn't break). Notice how Hotchkis etc. has braces for the GM A bodies rear control arms? If a control arm is only supposed to transmit force along its axis, what the heck to do you need a brace for? The answer? The ultra stiff bushings require the control arms to flex, but boxed in control arms don't... so the frame mounts do, but the braces won't let it. So what is flexing now?
I just bought Herb Adams "Chassis Engineering" book and started reading it last night. He discusses the various types of suspension bushings early in the book. He says that rubber is used by OEM manufacturers primarily because it is cheap, and adequate for grocery-getting. He says that polyurethane bushings are an improvement, but have their problems - the chief one being the tendency to bind. Regarding the increase in vibration transmitted to the car, he says that going from rubber to any of the "solid" bushing types (polyurethane, nylon, Del-A-Lum) is rougly equivalent to raising the tire pressure by 5 psi on your car.
So if you're contemplating switching to poly, but are concerned about a rougher ride, an easy way to get an idea as to whether you can live with the increased NVH (noise, vibration, harshness) is to just raise the tire pressure by 5psi at all four corners of your car, drive around for a while, and see if it bothers you too much. What is a rough ride to one person is quite acceptable to another, so this is a better approach than taking someone else's advice.
My car now has poly front control arm bushings, sway bar endlink bushings, and rear lower control arm bushings. For my tastes the slightly rougher ride is still totally acceptable, still erring on the side of too soft for my tastes. But then I found the car in stock form felt like a big bowl of overcooked oatmeal - mushy almost beyond belief. As I said, it's very largely a matter of personal taste, when it comes to street handling. On the racetrack there's an objective measure of performance - lap times; a lower lap time is better handling, no doubt about it. On the street its all about feeling good to the driver, and that's very subjective.
I would say upgrading bushings are the last step. Polyurathane seems to be an O.K. compromise. The problem is they do tend to bind. Many people assume a stiff ride is a good handling one. Not so. If it were true, simply bolt solid steel rods in instead of shocks. Solid bushings (Herb Adams' Nyliner and Global West's Delalum) are supposed to be the best, but they transmit road noise and vibrations to the chassis.
Polyurethane or harder bushings do not absorb road shock like the OEM style rubber bushings do. This yeilds a shift more responsive suspension. There is a cost to this. The shock is transfered to the chassis of the car, after prolonged use, stress fractures and cracks can begin to develop in the frame sockets that receive the control arm bushings. When I say "prolonged use", I mean regular street use. In race applications, road racing or drag racing poly (or harder) bushings are an advantage.
One last note, resist the tempation to put solid or solidish bushings in the rear upper control arms. When the car leans in a turn, something has to give back there - let that be the bushings.
Car Craft did an article on bolting on aftermarket rear control arms on GM A-bodies (Cutlass, etc) about two months ago. They describe it as a pretty straight-forward process.
There is information on the Olds FAQ about the aftermarket front upper control arms and swaps to a longer spindle. Stock front suspension geometry is pretty bad on A-bodies (I don't know about other Olds) and if you have the resources and time the swap to longer spindles will be well worthwhile. I have an old Hot Rod or Car Craft article on the then-new Global West upper arms, complete with before and after measurements on lateral acceleration, etc. Email me privately if you want me to send you a photocopy of the article.
Before you change the springs. Consider roll cage. There are many ways to hide a roll cage so its not as unsightly on your daily driver. But basically, it doesn't make sense to put super stiff springs on a chassis that is basically a wet noodle. Now your car is a full frame car. You could really improve things with solid or urathane bushings between the body and frame.
Shocks and Springs:
Springs are relatively cheap compared to the hassle of installing them. For that reason I would suggest shopping for a good price but getting new not used. There are enough companies out there that will wind you a spring in any rate you want.
Shocks and springs have different, and complimentary functions in a car's suspension; the springs carry the load, the shocks damp or control the motions of the car on the springs. Air-shocks are manufactured primarily to add some spring rate (help carry the load) to old, weak,sagging springs; the problem is that in the process, the air shocks trade off effective damping of the spring. This will typically give you a queasy, heaving, car-sickness-inducing ride. I well remember a friend with a 1970 Caprice with air-shocks to jack up the sagging rear - I called it the "vomit comet", after the NASA zero-g trainer aircraft, and I'm not susceptible to car-sickness normally.
My suggestion is to use shocks that suit your taste in handling, whether stock-replacement Monroe's, or the firmer KYB's, or the even firmer and more expensive Koni's. The KYB's and Koni's will give you a ride that is more "snubbed down", with less of that heaving and plunging. If you want better handling than shocks can get you on their own, change the springs to stiffer aftermarket ones along with upgrading to stiffer shocks.
My suggestion is based on the assumption that you want better handling on the street. If the car is a drag-racer things can be very different, as others have pointed out air-shocks can help preload one rear tire to reduce wheelspin on launch, help put more weight on the rear tires for better traction, etc.
To improve traction on a car with rear coil springs, you will want to use weaker rear springs, NOT stiffer ones. The desired effect is to distribute as much of the vehicles weight on the rear tires as possible. Thus, the nose lift is a good thing. As this is allowing the weight to "transfer" to the rear of the vehicle. For straight line acceleration, there are many ways to tune the stock suspension for better weight transfer for improved traction. However, the price for these kind of modifications is a loss of any cornering abilities. As I have said before, it is not possible for a suspension to be setup setup for corners AND straight line. Any compromise will result in a car that does neither one well.
You will prolly hear that the stiffer rear springs make the car oversteer on roughly paved turns. This is a pretty common opinion but not true in my experience. My 442 had weak springs that had a big oversteer problem. The rear would just "skip" out of place over choppy pavement. After I upgraded to stiffer springs, the car had much more stability in the turns. I think it was due to a better relation between the shock resistance and spring rate. With both springs I used the firmest Monroe shocks I could get, in new condition. My non-Olds daily driver is an old police cruiser with ~very~ firm springs, front and rear. It has shocks carefully matched to the spring rate. This car will go around the roughest corners very quickly with a very firm grip on the road.
That said, the variable rates are claimed to offer a softer ride at installed height, and still have capacity for a full cab or trailer. The heavy duty springs probably have a sportier feel. The manufacturers most likely publish a chart with all the specifics, such as installed height, spring rate, coil thickness etc. to compare the individual springs.
Some folks buy new shocks and are disappointed that their car doesn't handle significantly better. Usually, they buy shocks when the real problems are worn springs, and tore up suspension bushings. If your springs, ball joints, and bushings are in good shape, some quality gas-charged shocks will probably do the job you are asking for (Monroe, Gabriel, KYB's).
I might get some of the terms mixed up with "proper" terms, so I'll use "re-bound" to mean an extending suspension, and "bound" to mean compressing.
For the purposes of this discussion "strut" and "shock" are interchangeable, it is the damping effect I am talking about. Technically a strut is a "McPherson strut" used exclusivly in a McPherson suspension strut assembly, but it is often used to mean shock, when the shock absorber is a structural part of the suspension assembly and not just a "bolt on goody". There are lever shocks and dampers too, and other types, but they all do the same thing: damp bounce.
If I start with a standard "family" saloon, these are generally fitted with an average suspension, neither hard nor soft, nor high nor low.
If you take the factory standard strut for one of these cars they have about the same bound and re-bound resistance. This has the effect of averaging the car out in the middle of the suspension range. I.e. it travels neither high nor low.
Moving to a "sports" suspension (e.g. FE2, FE3) the manufacturer makes some changes:
1) The springs (coils) are stiffer.
2) The car rides lower.
You need 1 to allow 2.
The lower ride improves handling. The stiffer ride improves handling at speed as the car is less affected by bumps in the pavment surface at speed. The trade-off is that the car tends to be harsh at lower speeds.
Looking at the struts though they have different characteristics. Now the bound is easy, but the re-bound is stiff. I.e. the strut has asymetric behaviour. It compresses easily as the springs are already stiff and extends slowly to keep the car low.
While I have no direct experience of off-road vehicles, they tend toward the other end, they need a long travel suspension, so the struts are "swapped" round, they are stiff on bound and soft on re-bound, encouraging the vehicle to ride "high" ready for the next big bump.
I have bought aftermarket struts from reputable suppliers for years and they have always supplied the right "behaviour".
As a generalisation the after market strut tends to be a little stiffer than the OEM one (say 5%), though some manufacturers allow you to set the stiffness.
Gas charged struts tend to have better performance than fluid ones over the long haul, they are more responsive.
The clever things that go on in the design of a strut though involve "variable" damping, whereby the resistance of the strut to bound/re-bound depends on how hard it is "hit", making the strut softer on bad roads in an attempt to improve the feel of it.
In expensive suspensions, this is controlled by switch (e.g. Corv*tte) so that you can "enjoy" a soft (smooth) ride at low speed, but as your speed rises, the suspension "stiffens" up to improve the controllability.
A soft suspension travelling at high speed along an average road becomes very difficult to control as the car is deflected too easily from the chosen course.
So in summary: An average family saloon has symmetrical struts and rides "mid-height" A sports saloon has lowered suspension with easy bound and stiff re-bound, tending to ride low.
You can sometimes see when a car has the wrong struts fitted as the front or back rides too high/low compared to the other end or the ride height is just wrong all round. Jon Gordon-Smith
The front swaybar and the rear swaybar have to work togather with each other.
Simply installing a larger front bar with no rear bar will make the car understeer worse than it does now. Adding a larger front bar without also upgrading the rear bar will make the car understeer even more than it does now. Additionally, adding a larger rear bar with no front upgrade will make the car potentially oversteer. The front and rear bars must be upgraded as a set to get optimum handling from the car. Unfortunately, there are no larger factory rear bars that I'm aware of (the Trans Am rear bar is different), and aftermarket is your only option. Unfortunately, they are big bucks.
Note that these are first-order effects and there is some second-order advantage to a larger front bar by itself, namely that it does reduce body roll, keeping the front tires in a more upright position as you corner, and thus improves front suspension geometry in a given turn by reducing suspension deflection.
For example, I added a junkyard 1 1/4" front swaybar to my '72 Supreme knowing full well that it would make the car understeer more, but I found that despite the understeer the car handled better than before. Part of the reason that A-body cars understeer so much is that the tires don't stay upright on the road when the car rolls, but instead tip over and lose some grip as a result. (Understeer == less grip at the front than at the back). The stiff swaybar reduces body roll, which helps keep the tires more upright, which improves their grip, so the car understeers less than before due to the reduced body roll. On the other hand the stiff bar increases weight transfer at the front, which reduces grip and increases understeer. The combination of the two opposite effects ends up with the car not understeering significantly more with the fat front sway bar.
The 64-72 A-bodies have a terrible camber change with suspension travel (hence the reason for the B-body spindle conversion) and the larger front bar, while increasing understeer, will limit this camber change by limiting suspension travel. Unfortunately, the larger front bar by itself counteracts some of the benefit of the reduced camber change. Don't know if it's a net gain or not, as a "seat of the pants" feel is obviously very subjective. Or in other words, the A-body front suspension geometry has a poor roll center design, so reducing suspension deflection during cornering helps keep the tires upright in the turn, improving tire contact. This is the problem which is corrected by using the B-body spindles and the Global West or Hotchkis upper A-arms.
The handling response of a car is the function of a number of different items. The front suspension geometry, and the resulting motion of the tires as the suspension moves through it's travel, obviously also have a great effect on the handling of the car. A larger front bar will likely provide an improved feel in the A-body cars despite the additional understeer. This is due to the roll reduction resulting from the larger bar. This reduced roll, and thus the reduced deflection of the front suspension, keeps the tires in a closer-to-optimal orientation relative to the road. This is especially important in the A-body cars, with their well-documented camber change with suspension movement. Reducing the suspension deflection reduces camber change and improves handling.
As a data point, the Vista Cruisers used a 1" bar with no rear bar, larger than the 442's 15/16" (and later 31/32") front bar. The VCs understeer like mad (conventional wisdom in Detroit was that it was safer for the general public to go off the road nose first than tail first), but I have to think that if Olds engineers felt that this larger front bar helped 442 handling they would have used it.
Maintaining the same torsional stiffness ratio from front bar to back bar as was the case on the factory 442 setup will certainly help. Note that I'm talking about sway bar torsional stiffness, which is not the same as diameter, though diameter is probably a good first approximation. Maintaining the same 15/16:3/4 ratio using a 1 1/4" front bar would require a 1" diameter rear bar.
Note that this setup will still understeer, however the reduced body roll will still improve handling. To make the car more neutral (or even oversteering, if you prefer that), you'll need to use a rear bar which is even larger than the front. That's why Herb Adams sells the mondo 1 1/2" rear bar.
As far as I know the torsional stiffness of a sway-bar depends on the fourth power of its diameter, so keeping the ratio of front and rear sway bar diameters the same should work. Figuring that 1 1/4" front and 1" rear bars will result in some understeer, I decided to use the 1 1/8" rear bar from Original Parts Group that I mentioned earlier. However theory says that it will understeer less (or oversteer more) than a 1" rear bar.
I would also like to point out that you can alter the understeer/oversteer balance with the spring rates as well as the sway bar thickness - stiffer springs at the rear will shift the handling balance towards oversteer. Stiffer rear springs will also roughen the cars ride, though. Global West Suspension (www.globalwest.net) is one source of rear springs in several rates. They actually make some rear springs so stiff that they recommend using *no* rear sway bar with them!
One final note is that if financial considerations force you to upgrade in stages, definitely get the larger front bar before the larger back bar. The car will understeer, but that is probably easier to catch and correct than a car which oversteers (for example, if you still had the pencil-necked factory front bar and added a 1 1/2" rear bar, you'd probably start swapping ends like an early Porsche 911).
Especially given the turtle-slow steering on our cars, it will be quite difficult and dangerous to cope with severe oversteer, as you simply cannot wind the steering wheel fast enough to catch a major slide, even if you have the driving skills required. And if and when you do catch the first slide, the usual result is a counter slide in the opposite direction.
Regarding heavy sway bars affecting ride quality, as well endlink length, Energy Suspension points out that for the swaybar to work best its ends should be horizontal with the car at rest on a level surface. The stock endlinks on my Supreme were too short for the stock 7/8" bar, letting its ends droop significanly downward.
One more thing - for the sway bar to affect ride quality as little as possible, it should have no preload. This means that with the car on a level surface with a load equal to what you will be carrying on average, the sway bar should not experience any twist. For this to be true, usually one endlink needs to be slightly shorter than the other, probably the one on the drivers side. My solution is to use one regular endlink, but for the other side to remove the spacer on the endlink bolt and instead use two nuts snugged up against each other to set the endlink length. Do this with the car on level ground and a sack of sand or something in the drivers seat. Just set the nuts so that the endlink bushings all have about the same preload force on them.
Larger rear sway bars generally result in oversteer, which results in a very dangerous situation, especially on the street. It requires a good bit of driver correction... in extreme situations it requires turning the wheels in the opposite direction of the turn (picture Sprint cars on a dirt oval). Even in cases where the rear bar is the same diameter as the front, a poorly balanced car will most likely result. This isn't fun to drive, in normal cornering the front wanders and can be loose feeling.
When the geometry of the front and rear bars is identical, then a larger rear bar will cause oversteer. Usually, however, the geometry of the rear bars is significantly different from the front, so you can't compare the front and rear bars by size (just as you can't compare the front and rear spring-rates, due to the different position of the springs in the suspension front and rear). The rear bar is bolted to the lower control-arm, and thus has a much longer lever-arm working against it (the whole rear control arm, from its front pivot to the center axis of the rear bar) than the front lever arm (which is that part of the sway bar that goes back from the bushings to the end link), so you'll need a thicker bar (generally 1.5") to get similar roll-resistance to the front bar; thus, even with a 1.25" front bar, the front would still have more roll resistance than the rear with a 1.5" bar.
I recommend calling Herb Adams if you are considering new sway bars. He has done a lot of research with RWD GM's (almost exclusively). Ask the tech support how to match what you have. The R&D on this is time-consuming, and that's what you're paying for (it doesn't cost $120 just to bend a length of spring steel into a sway-bar). BTW, I think Herb Adams sells a 1.5" bar for the rear of most RWD GM cars.
Generally, before you add a rear sway bar, you want to swap the stock front bar for a slightly larger sway bar. In any case, a larger rear bar doesn't result in better handling, 99% or the time it results in a poor handling car that might not show just how poorly it handles until its too late.
On the other hand, GM designed a *lot* of understeer into its suspensions; you'd need a huge rear bar, plus a beefy front bar, to approach anything like neutral handling, never mind oversteer.
In addition, a larger front bar will almost always improve handling, due to it keeping more of the tire patch in contact with the road. Though it theoretically will make the front stiffer, and thus understeer more, usually it just takes out the excessive roll that puts the tires on the sidewall with that bad front-end geometry, so the car will understeer *less* with a slightly-stiffer-than-stock front bar. With he improved front-end geometry from a taller spindle, however, a stiffer bar might in fact cause more understeer, rather than less.
An evenly balanced car (the goal) has zero understeer and zero oversteer. Roll Couple Distribution (RCD) is a term used to describe the relationship of the front's roll rate to the rear's roll rate. Roll rate for either the front or the rear is the sum or the two spring rates and the sway bar's rate. To find the optimum RCD (which will probably be be somewhere along 75%-85%), you need to know the front weight bias, or the weight on the front tires compared to the weight on the rear tires. Front Weight Bias Optimal Roll Couple Dist. 60% 67% 59 69 58 71 57 73 56 75 55 77 54 79
A higher roll couple results in understeer, a lower roll couple results in oversteer.
How to Make Your Car Handle, Fred Puhn, HP Books
How to Build the Ultimate Super Street Mopar Mike Martin, S/A Design
(although this a mopar book its relevant, suspension theory transcends the manufacturer and brand loyalty)
[ Thanks to John Carri, Bob Barry for this information. ]
Tires and Wheels:
I have heard many times that the biggest single improvement to handling you can make is switching to wider wheels and better tires, so that might be a good place to start, so long as your suspension bushings are not so worn that they'll cause accelerated wear on your new tires. For maximum lateral grip, don't put the widest possible tires on your rims - rather use about the narrowest tire that will fit that rim. Using too wide a tire bows the sidewalls in, reducing lateral rigidity of the tire. A 225 or 235 tire on an 8" wide rim will give you MORE lateral grip than a 255 tire on the same rim. (I expect some shouts of outrage from other listees over this one, but several books on handling explain this. Fred Puhns How to Make Your Car Handle is a very interesting book full of fascinating information on improving handling, well worth reading.) Of course a wider tire might improve straight-line acceleration, so you have to trade off between max. lateral grip and max. straight-line acceleration.
The number one thing to improve the handling of a car is better tires and wheels. The problem with late 70's GMis you will be looking for zero offset 16 and 17" rims. They are tough to come by. The only ones I found where ROH. Contact Discount Tire (look in some of the car magazines - Road and Track etc. - check the net as well)
If you look into the car mags for the hottest street car shootouts, a good portion of those 8 and 9 sec. cars will have only 10" or 12" tires on them. The trick is in the suspension set-ups (getting something that'll hook good, etc.) rather than bigger meats. That is a stock suspension using an airbag to pre-load the suspension.
[ Thanks to Greg Rollin, John Carri, Jeff Carter, Doug Ahern, Joe Padavano, Bob Barry for this information. ]
This is not an all inclusive list of aftermarket suppliers, just examples of what has been discussed on the Olds Mail List.
Name Website Notes Addco www.addco.net Sold through retailers Global West www.globalwest.net (714)923-6180 - Sold directly Herb Adams Sold through retailers HO Racing CROCIE@MSN.COM www.inc.com/users/HORACING-ps.html Sold directly Malibu Performance (818)222-6725 Wilwood www.wilwood.com
I believe Herb Adams makes 1-1/3" bars which are slightly thinner, but these appear to be for all-out racing, with Heim joints instead of endlink bushings and a correspondingly high price. (Probably lots more NVH than polyurethane, too.)
Another possibility is Global West Alignment in the San Fernando Valley. They also market the ball joints and hardware necessary to add the F-body steering knuckles to an A-body. In addition, Global West markets a tubular upper A-arm for use with this knuckle. The new A-arm eliminates the need to use excessive numbers of shims to maintain proper wheel alignment with this knuckle - the stock A-arm must be shimmed significantly inboard in this application, resulting in potential clearance problems with headers, and safety issues caused by too many shims.
[ Thanks to Terrill, Joe Padavano for this information ]
Caster settings have a tremendous effect on "wandering" and "road feel". The more postitive the caster settings, the more the car has a tendency to straighten the wheels by itself after a turn, plus be a bit more resistant to turning the wheels to begin with. Postive caster is when the top ball joint is slightly rearward of straight up and down from center compared to the lower ball joint. Negative caster is when the upper ball joint is on a plane forward of the lower ball joint.
Camber settings MIGHT have something of an effect as well. Roads are typically engineered with a "crown" in the center to avail for water drainage. Camber settings are adjusted accordingly in most instances to accomodate. If there's too much "straight up" in the settings, the car can tend to wander. Again, most of the time, the driver's side is set at a positive miniscule amount, such as +1/4 and the passenger side is set at 0 or MAYBE just a smidgen of a negative amount. Postitive camber is when the top of the tire leans out farther than the bottom, and of course negative is when the top leans inward.
Toe-in (or toe-out) settings may also play a part in the road feel. If toe-out is present and is excessive, then you could find your car wandering a bit. Typically, toe-IN for your car is around 1/8", but consult a manual to be sure. Toe settings are performed while the car is at rest, so when all the friction forces and linkage play are taken up when the car is moving forward, the toe settings SHOULD theoretically be zero when the slack is taken up.
Also, since the idler arm was replaced, and the pitman arm is just a "hunk of metal", then the center link ball/socket, where it connects to the pitman arm, may be at fault. Or tie-rod ends.
A note about those ball/sockets. They are spring loaded to keep slack out of them during their life, however, after time, the springs become weak, and the firmness leaves. If you take your car to have it checked by a mechanic, they MIGHT try and use channel-lock/water-pump pliers on them to squeeze them and show you they are "bad". Don't trust this method. Your grandmother can get them to deflect using pliers. The "tried and true" method of checking is using only your hand to squeeze the ball/socket to try and compress the spring. If it's tough as nails, it's probably ok. If it mushes in like today's fresh-baked Wonder bread, you might need to replace the faulty parts.
My understanding is that the 1973 and later cars use a different ball joint taper than the 1972 and earlier cars. While these later spindles will physically bolt up, the taper will only contact at one end or the other, as opposed to contacting over the entire length of the taper as designed. This results in bending of the ball joint stud under load, which can lead to metal fatigue and ultimately failure (as in the spindle exits the car in the middle of a high speed turn).
I seem to recall that virtually all mid-70s and later GM RWD cars use the same ball joints, but these are different from those on the 1964-1972 A-body cars (for example, the 1970-81 F-body, 1973-77 A-body, and 1977-up B-body use the same part no. upper and lower ball joints - not sure about the other RWD cars, in particular, I don't know if this applies to the G-body cars). This is why H.O. Racing (RIP), Hotchkis, and Global West all sell or sold kits for installing these later spindles on the early cars that include new upper and lower ball joints with the appropriate tapers.
As a data point, the 1973-up lower ball joint is used in the 1964-72 application by machining down the portion of the ball joint housing that fits into the lower A-arm to 2.010". I think the 1973 upper ball joint can be used in the early arms as-is, but I'm not sure about that one.
Note also that the later spindles are taller than the 1964-72 spindles, which is good in that it improves the front end geometry for better handling but it's also bad because you must run an excessive amount of upper control arm shim to get the alignment correct. That's why Hotchkis and Global West also sell their shorter upper A-arms.
Please be extra careful on this one to ensure that the tapers match, as it's a definite safety issue.
[ Thanks to Joe Padavano for this information. ]
Polygraphite bushings are worlds better than polyurethane. Polygraphite is just as dense (to resist deforming), but is much more slippery and thus prevents the "lurches" common to polyurethane equipped cars.
On rubber vs. poly, the rubber is fine unless you really like to push your car. If you want that last little bit of cornering go with the poly, but if you want ride quality stick with the rubber.
OEM Bushing Pro's - Cheap, Easy to find, Mechanics know what to order/install, the ride is "stock". OEM Bushing Con's - Any type of weather wears them, "deflection" causes problems as they wear. Any other components that are upgraded (springs, shocks, etc.), cause the bushings to "deflect" more. Poly Bushing Pro's - Highly resistant to weather, salt, oil, chemicals, etc. Deflect very little. Come in colors. Polygraphite bushings are self-lubricating, no squeaks, because they are impregnated with graphite. Poly Bushing Con's - More expensive than OEM, rumored to squeak (mine don't). May cause weak/old control arms to flex (had mine boxed to make sure). Del-A-Lum bushings Pro's - Probably the best performance bushing you can buy and use. Del-A-Lum bushings Con's - A bit of an over-kill for the street. They are better suited for all out performance and racing.
When rebuilding my rear suspension, I opted for the PolyGraphite bushings, new OEM springs, and air bags. I put Gabriel gas shocks on, but need a better shock (like KYB). This is a '65 98 and is a daily driver. My ONLY regret is that I am now having trouble getting Energy Suspension to sell me a kit for the front end (this is not a problem for the Cutlass/442 crowd).
I have had the PolyGraphite bushings in the rear lower control arms of my 1965 98 for a little over a year. No squeaks (although they may take 2 - 4 years to squeak). I live in S. Ca. so, the weather is kinder on parts.
Most places sell Energy Suspensions Polyurethane or PolyGraphite bushings. The first can be bought in different colors, the second ONLY come in black.
You may always have some squeak or harsh ride from poly bushings. If you aren't looking for a performance suspension, then go with the factory rubber. The car will return to its original designed ride, and you won't have any surprises. The poly bushings are harder, so they don't flex as much, thereby helping in the handling department. There is nothing wrong really, but it will definitely affect the ride. The polys also have a tendency to squeak, but since they don't flex much, they also transmit more road shock to the frame, giving you a harsher feeling ride.
For those not wanting a performance suspension, go get what the GM design engineers spent thousands of dollars on research on - rubber bushings. They work. I've had polys, and they definitely enhance handling, but do ride a little rougher. Plus, I ended up having to replace them in about 4 years. So guess what I went back to.
Want CHEAP hard body bushings? Try used hockey pucks. Sure, you will have to do a bit of cutting, but that is really cheap.
[ Thanks to Dan Lacey, Mike Bloomer, Mike Rothe for this information. ]
1968 - 1972 A-body:
All 68-72 GM A-body cars will interchange, however there is some variability in the use of round vs. oval bushings. The oval bushings are designed to provide a less jarring ride over bumps, so look to the lower-line cars (Chebby and bottom of the line in the other divisions) for the round bushings. Also, I think these were phased in over that 1968 - 1972 span, so check the earlier cars (1968 primarily). The oval bushings used in the lower A-arms of some A-body cars are designed to deflect rearward slightly under high impact loads (like hitting a pothole or rock). In this case, handling precision was sacrificed for ride comfort.
[ Thanks to Joe Padavano for this information. ]
Rear Control Arm Bushings:
I used an air chisel with a blunt attachment to remove the bushings, and I used a length of steel pipe, several large thick washers, and a long grade-8 bolt. I don't remember the exact sizes/lengths of the pieces, but you need pipe of a diameter that will fit over the small end of the bushing and slightly longer than the bushing, some thick washers that don't fit into the pipe, some thick washers that do fit into the pipe, and a bolt that is longer than the pipe's length plus the bushing's length.
I still maintain that the easiest way to remove the rear bushings is to drill the rubber out, knock the center sleeve out, then collapse the outer shell with a chisel. This method has always worked best for me. DO NOT BOX the uppers. It "may" be wise not to use stiff bushings on the uppers if you use stiff bushings on the lowers. This 4 arm system was designed to flex a "little". Making everything too stiff may cause something to give (read: break).
To install the bushings, install the bushings in the housing, put the smaller washers on the bolt, and the bolt through the bushing so the threaded end extends through the bushing and the housing. Place the pipe over the housing opposite the bushing, put the larger washers on the bolt, and install a nut. Tightening the nut will cause the bushing to be pulled through the housing and into the pipe.
There are pictures, descriptions, and a much better explanation of this procedure in the July 1994 issue of Performance Musclecars (which I'd be glad to scan and send to you).
I bent several bolts, and several washers, but it actually worked. I only spent about an hour doing the second car, after spending lots more time than that cussing and the first one!
I just hammered mine in, using a flat piece of steel between the hammer and bushing to prevent marring. The axle was out of the car. Non-petroleum based grease/oil made things easier. It helps to get mad at it.
[ Thanks to Sean Fay, Robert Lavey, Stephen Hoover, Jeff Carter for this information. ]
Front Stabilizer Bars
Anti-roll bars from Chevy vehicles tend to be thicker than other GM cars, except for cars with handling packages.
If I remember correctly, the sway bar effectiveness goes up as its diameter to the power FOUR, so a 1-3/8" bar has 1.46 times the roll stiffness of a 1-1/4" bar, and 6.1 (!) times the roll stiffness of the stock 7/8" bar, assuming similar metallurgy for all bars.
Mid Size Cars
Interchange for your Olds:
Olds Vehicle GM Vehicle Notes 1964-1977 A-body (Cutlass) 1970-1981 F-body (Camaro, Firebird) 1964-1972 A-body (Cutlass) 1977-1985 B,C body (Delta 88, 98) 1978-1988 A,G-body (Cutlass) 1982-1992 F-body (Camaro, Firebird)
Vehicle Year Bar Size 1978-1980 Formula, Firebird 1 1/4" 1976-1979 Trans Am 1 3/4"
The A-body (Cutlass) sway bars from 1964 to 1977 were the same width. The 1978 to 1988 G-body (Cutlass) bars are different widths.
Make sure to get the sway bar frame brackets, especially when you are using a bar from a different platform (eg. F-body, Firebird, bar on A-Body, Cutlass).
Sway Bar End Links and Bushings: 1 1/4" front sway bar off an '81 Trans Am that I had on my car was getting awfully close to the tie-rods where it crossed over them - on close inspection I could see scrape marks on the sway bar where it had hit the tie-rods. I couldn't see a way to fix that problem, so I took the front sway bar off the car. I believe I need a different design of sway bar - the F-body bar I was using has a sort of dip in the ends that brings it close to the tie-rods, and that dip is certainly not necessary for the bar to fit the car.
I bought the kit for a TransAm and that's not an option, the sleeves are significantly shorter, though I ended up using the urethane bushings and stout bolts from that kit. It almost seems that you need an end link sleeve that is 1/2" or so longer than stock. I have not been able to locate these.
Actually you can't install the bar without the T/A bushings anyway. The F-Body WS-6 cars used a higher durometer (read stiffer) rubber bushing in their sway bar links to increase the effectiveness of the bar. I bought the T/A end link kit, used the urethane bushings that came with it and threw the rest away since I needed the A-body end link bolts and sleeves to make it fit right.
I have a sway bar off a WS6 78 T/A and got my bushing kits for the Firebird, not an Olds (at the time, the bar was on my 70 Firebird), both the end link bushing set-up & the frame bushings bolted straight across to my 68 442 Conv. What a difference!
Of course, the problem you're concerned with is: which one fits? I can't say for sure that the end links are the same length for the A-body and the F-body, as suspension travel may differ, resulting in clearance issues. One option is to have the parts store pull both and compare the lengths of the bolts and spacers. If the bolts are the same length but the part numbers differ, I'd get the F-body link as it will likely have the stiffer bushings. If the bolts and spacers are different lengths, I'd go with the A-body part (which will fit the F-body sway bar in any case). Conversely, just get an aftermarket polyurethane kit for the A-body.
Well, this is going to sound rather redneck and shadetree, but here's the fix. Take an old end link sleeve and cut two equal lengths off (about 1" should do - I cut 1/2" from the original spacer sleeve). Then install the bar and put these "extensions" in with the regular spacer in the end link, to move the bar higher.
This, combined with making sure the clamps on the tie rods adjusting sleeves are facing down, should give you enough clearance between the bar and the tie rods. If it doesn't work, you can get a longer bolt and add more spacer.
So what you have are two links stacked on top of each other. If you're really worried, just weld them together. Unless they split at the seam there's no problem. Since it's just a straight vertical load, there's very little chance there's really no problem. You could also cut a piece of tubing of the correct diameter to the correct length. It is just a spacer, and as long as the ends are square, they will just butt up against each other and be fine. Have many hard miles on mine with no problems.
As for longer end-link sleeves, I think Energy Suspension makes them in several lengths, or you can buy some tubing and hacksaw it to length, or you can just discard the sleeve and use a nyloc nut above and below the sway-bar bushings. Keep in mind, though, that ideally the ends of the sway bar should be horizontal with the car at ride height, to keep the endlinks from angling severely as the suspension travels.
You also realize, of course, that you'll need different frame bushings for this bar as well, due to the larger diameter. Again, I suspect you'll want the F-body parts. I've also heard that the stiffer bar can cause the self-tapping bolts which hold the bar to the frame to pull out - I've seen people use nut-serts in the frame to provide a stronger connection.
[ Thanks to Mike Bloomer, Glen Hankins, Greg Beaulieu, Trevor Lee, Fred Nissen, John Carri, Joe Padavano, Scott Wheeler, Chris Ruper for this information. ]
Full Size Cars
Interchange for your Olds:
Olds Vehicle GM Vehicle Notes 1977-1985 B,C-body (88, 98) 1964-1972 A-body (Cutlass) 1977-1985 B,C-body (88, 98) 1970-1981 F-body (Camaro, Firebird) 1977-1985 B,C-body (88, 98) 1986-1996 B,C-body (Impala)
Vehicle Year Bar Size 1978-1980 Formula, Firebird 1 1/4" 1976-1979 Trans Am 1 3/4"
Center to center dimensions of B-body front bars is 47".
A healthy front bar, like one of the above, is rumored to make the big cars handle like slot cars when combined with a 1.5" Herb Adams VSE rear sway bar.
[ Thanks to Fred Nissen, Mike Jones, Greg Beaulieu for this information. ]
1964 - 1972 A-Body:
The tubular Hotchkis arms are pricey (~$500/pr), but they do two things: They allow the use of 78-up B-body (not F-body) spindles for the bigger brakes and the resulting package greatly improves the geometry of the A-body front suspension for better handling.
Many of the B-body cars had 11" rotors (4 3/4" bolt pattern). You need to find the ones with the optional 12" rotors (5" bolt pattern). The Camaro rotors bolt on to the B-body spindles and allow you to retain the 5 x 4 3/4" bolt pattern (the big cars used 5 x 5" on the 12" brakes). C-body cars used a larger rear bearing than B-body cars.
The Hotchkis arms come with polyurethane bushings and new (Impala) ball joints. The stock lower arms must be fitted with the Impala lower ball joints, requiring the new ball joints to be machined down to 2.010" to fit into the A-body lower arms. The only other potential problem is the tie rod ends. Apparently, GM went to a metric taper at some point. Hotchkis provides the data as to which year spindles and tie rods to use.
Hotchkis supplies you with a list of part you need to make the conversion. What I got from them was a one-page list of part numbers for the items you need. Unfortunately, it doesn't list applications, just part numbers.
Part GM Part No. Notes Spindle, left 18016023 Spindle, right 18016024 Dust Shield, left 344023 Dust Shield, right 344024 Rotors (2 req) 18016035 (these are the 88-92 1LE parts) Brake Pads 12510010 Caliper, left 1801427 Caliper, right 1801428 Caliper bolts (4 req) 5463495 Spindle nuts (2 req) 378137 Spindle washers (2 req) 457707 Dust Caps (2 req) 14003444 Wheel Brgs inner (2 req) 457196 Wheel Brgs outer (2 req) 457049 Grease seals (2 req) 3965092 Tie Rod outer (2 req) 7837733 (from 78-88 G-body) Use for 64-70 cars Tie Rod outer (2 req) 12322633 (from 73-77 A-body) Use for 71-72 cars Lower Ball Joints 9767113 (from 78-up B-body)
Note that the lower ball joints are the same ones used on the 73-77 A-body and 70-81 F-body. The part of the ball joint which presses into the lower A-arm must be turned down to 2.010" by a machine shop.
The list from Hotchkis also lists Wagner, Bendix, and Moog part numbers where available. These are probably less expensive.
Also, remember to get the droop stop kit (Hotchkis #2401) to prevent breaking the upper ball joints. This item is not included with the tubular arms and lists for $33.96.
[ Thanks to Joe Padavano for this information. ]
1965 - 1970 B, C-Body:
Along the way, I took what I thought of as a calculated risk that the Hotchkiss 64-72 A-body stuff would bolt up correctly to my 1966 98. They work.
Yes. A body trailing arms both the upper (inner) and lower (outer) swap into the 1966 big cars. The suspension was the same for the 88's and 98's from 1965-1970, so by extension this should work for other years too.
What this means is that you other guys with big cars can get & use those boxed trailing arms that Hotchkiss builds for the Cutlass / 442.
[ Thanks to Chris Fair for this information. ]
Aluminum, Polygraphite, Polyurethane Bushings In General
Poly bushings are very sensitive to how they are installed. If not done properly you will get constant squeaks and binding. From what I've read on the technical side is that poly does it's best job in compression applications. Things like body mounts and sway bar end links are the perfect examples. It kind of seems to me that if you want the performance idea of having no deflection that poly bushings will give you, then you might as well either go with heim joints (spherical rod ends) or solid bushings like Del-A-Lum (I believe Global West makes them) which won't be much stiffer than the poly.
This will allow free movement of the suspension with no binding at all and allow your springs/shocks to operate at their true rate. This is a must if you're really serious and do get to that "fine tune" phase of handling. For most street cars, a selective mix of rubber and poly will give you the best all around performance without squeaks and excessive binding. Please note that I haven't yet had an opportunity to deal with the fully grease-able bushings (the ones with the zerk fittings on them) yet but it seems that these may be the best compromise. If they function as I have been lead to believe, then they will offer the free movement of solid bushings but still have the poly isolators to relieve some of the harshness.
As I understand it, polurethane should not be used in any application where it might be deformed in shape by twisting forces. If the bushing needs to deform to accomodate any movement of whatever part is connected to it, then there may be a problem.
To clarify, look for instance at a front control arm bushing. The control arm pivots about the hole in the bushing, but it moves only about this one single axis, and the bushing doesn't have to deform for the arm to move - it just pivots on the hole through the bushing. This is okay. Similarly leaf-spring bushings, etc, should be fine.
What might not be okay - look at a rear control arm on a GM 4-link, and you'll see that when the axle moves up and down it (mostly) pivots about the hole through the bushing, like the front control arm does. This is okay. BUT, when the car is cornering, there are large forces pushing the axle sideways relative to the car. This tries to pull the rear end of the control arm sideways, and in order for the arm to move sideways it would have to deform the bushing. If you use a rubber bushing here it will deform, but recover shape when the sideways force lets up. Poly bushings will resist deforming more than the rubber will, but if ever the force gets large enough to deform the poly, that's it, it stays deformed; in effect the hole through the bushing will get ovalled out and never recover. If the bushing is stiff enough not to deform, then it will bind on its pivot instead. Neither alternative seems all that desirable!
Someone pointed out that a Panhard rod might try to force the axle to go one way, while the control arms are trying to make it move in a slightly different direction. The result is that the two might fight each other, and the bushings might bind. This problem is worse if the control arms are not parallel to the car centreline, like the Olds upper rear control arms.
I don't know how much force is needed to actually deform poly bushings this way. Several reputable companies (Edelbrock, Hotchkis, Global West, etc) make and sell rear control arms with poly bushings, so maybe they have a type of polyurethane which is stiff enough to not deform under even the largest cornering forces, in which case you can happily bolt them on and not worry about bushing deformation. Presumably things like the added graphite in the Polygraphite bushings are there to reduce the effects of binding; after all, bushings wouldn't squeak if something wasn't binding, would they?
I would be careful about using "better" bushings with original control arms. Make sure that original parts are checked (like Magnafluxed) and reinforced before re-installation.
Del-A-Lum bushings are a bit of an over-kill for what you are intending. They are better suited for all out performance. OTOH, they are I believe a better bushing than OEM rubber or Graphite. So you can make the argument that they are better suited for you since you *should* never have to replace them. This also takes into account that you are putting on Global West control arms. These arms were meant to be used with Del-A-Lum.
I ultimately went with the Del-A-Lum bushings for the front end. My rationale was:
The front control arms, due to the ball joints, do not need to twist the bushings the way the back arms do. The urethane bushings would still allow some undesireable lateral compliance while increasing friction around the nominal pivot axis≈. The Del-A-Lum bushings use a low-friction delrin liner inside the aluminum bushing, providing (in my opinion) a better ride quality with increased control of control arm motion. Note that I would not use the Del-A-Lum bushings on the rear arms without also using a heim (hiem?) joint on at least one end of the arm due to the need to allow twist. In the end, I decided to stick with stock rubber bushings in the back.
Don't the front control arms also move slightly back and forth horizontally due to application of the brakes? There must be some sideways pressure on the bushings during braking (therefore compression!)
As for being hard to put on, graphite should not be any harder to install than any other bushing. They also come pre-lubed with silicon grease. If you live in a very wet area, you may have to lube them after a couple of years. (This sounds like a pain in the ***). Do the Del-A-Lum bushings/Global West control arms come with a grease fitting?
If you are going to use boxed lower rear control arms, I would NOT necessarily box the upper control arms. The set of 4 control arms on the rear are designed to have some play in them (from the rubber bushings). Part of the expense for the aftermarket arms, boxed upper and lower, is because they typically use heim joints that allow the arms the ability to move in directions that the original arms could not. One suggestion would be to use stiff (graphite, etc.) bushings in the rear lower arms, and OEM rubber in the uppers. Please get some professional advice on this area since you are sinking enough money in this suspension to do it "right". (I on the other hand am going for the biggest bang for the buck!).
Polyeurothane bushings help the ride quality and the handling of due to front end weight. They help eliminate deflection which occurs in normal rubber bushings, from energy transmitted from the road by irregularities in road surfaces.
I can't speak for replacing the bushings in the upper A-arms, but did replace the lower A-arm bushings (Grace, the 71 Cutlass 'S' stock car) with a set of Energy Suspension units, and here's what I encountered:
1) If you have the arms with the oval rear bushing, some kits require you to use the outer shell from the old bushings (Energy Suspension's do) and there's not much I found that will work for removing the rubber part other than burning it out with a torch. It stinks, and if you don't have a big torch (the one I usually use was out at the time) it could take a little time. I'm not sure if it's better to remove the old bushing and burn out the rubber or leave it in place and do it in the A-arm, the shop I had press the bushings out (no press here) took the old ones out and reinstalled them after I did the dirty work. The front bushing's round, and it is just a press-out, press-in affair. It also might be a good idea to support the gap in between the sides of the arm as you do these, I think I remember seeing some spacers the factory used when installing them in a service manual.
2) When you reinstall the arms to the frame, put some anti-sieze or grease on the center of the bolt that goes through the arm, to prevent it from locking itself to the center of the bushing. I have a spare frame in the back yard that I have to get a friend to use his torch to remove the bolt so I can remove the arm. Water gets in there and rust-welds the two parts together, and then it's a fight to get them out. Seems to always get to the rear bushing more than the front one.
3) Sometimes the arm will not want to go back into the holes it came out of without some "persuasion", have a big hammer or mallet handy.
This is about all I can remember about the job. It can make a lot of difference in the handling of a car due to the stiffness of the polyurethane (or similar materials) keeping the alignment settings of the front end consistent during cornering. Stock rubber bushings do well for a smooth ride, but they do have a lot of give in them and they deteriorate after some time. And when they go bad, they can do a lot of damage if not caught in time -- had a car once I had to replace an A-arm on after a bushing failed and the center bushing shaft/bolt broke through the outer shell and deformed the arm bushing hole itself.
[ Thanks to Mike Bloomer, John Carri, Joe Padavano, Cliff Simpson, Scott Geiger, Ken Snyder, Dan Lacey for this information. ]
Polyurethene Bushings - G Body
I too, have Energy Suspension Poly bushings on the CC-IROC-SS-#1 prototype. I HIGHLY recommend the conversion. During installation you are to utalize the packet of silicone lubricant, (usually about 2oz supplied), on all flex points like, the upper control arm mounting shaft, lower control arm mounting bolts, and all the rear mounting bolts. All bushing internals get coated prior to the mounting bolt insertion.. This stuff comes packaged in a clear bubble pack. Snip the end and squeeze away. This stuff is like Vaseline except about 10 X thicker. There are a few different bushing compounds available. The standard Polyurethane and Polly Graphite. (though I only found urethane for the G-body Cutlass). The urethane usually come with a 2oz assembly packet of silicone grease. Polly Graphite bushings come with Graphite impregnated within. The second version helps fight later squeaks.
Before attempting the bushing swap, place the new bushings in a freezer for at least 24 hours. This will shrink the overall bushing and metal collars to their smallest dimensions. Allowing the bushing to more easily slip into place. I used an air chisel to remove the old bushings + collars. You might need to use a hydraulic press on yours. Assemble the units back onto the car. Hardly a squeak anywhere. For those squeak fanatics, a grease nipple fitting hole can be drilled (if not supplied) and fitting installed. Just make sure the nipples don't protrude from the bushing in an area where they will be broken off during suspension travel. I purchased a high temp silicone grease (milky-clear color) cartridge that's used solely on the bushings. This keeps replenishing the silicone slipperiness whenever the car is generally greased. I do occasionally hear a squeak.
By the way, I suggest that if you replace the bushings front And rear with Polly bushings, Do them all. Don't take any shortcut. There are separate purchasable bushings for the upper shock absorber mount shaft as well as the Swaybar mount bushings including adjustable drag link. Front and rear bushings come as separate carded sets.
After the Polly bushings + pro-Kit springs were installed, A world of difference arose in that the cars cornering attitude and suspension deflection rate became unbelievably controllable. Quincy's suspension felt like that of a small sports car. Cornering flat and nimble & taught like an independent 4 corner small sports car. The overall suspension improvement feels unexplainably fantastic. If it weren't for the cars weight, you could close your eyes and the G-force and flat attitude feels like a Pors*h. Just unbelievably GREAT. The ride is stiffer but not jarringly so. When standing still, it's hard to rebound the suspension more than 1". Yet the progressiveness of the Eibach springs allotted more than enough travel to handle anything in he way. The car stature also dropped apx 1.5" in ride height. The tires now set in the fenders as opposed to seeing the top tread visible. A world of difference in the cars visual.
Cost: Full set bushings front + rear: $289.00 Eibach Pro-Kit springs ≈: $319.00 Sway bar bushings + adjustable drag links: $39.00 Used 1:12 steering box: $50.00 Cartridge of silicone grease: $15.00 Front end alignment, (a must): $60.00 Paint for control arms + rear end: $10.00 Nitrogen shock replacements $75.00 ======= Total for hardware parts $793.00
I would estimate the total shop time (at apx.) to convert all the car components as mentioned to 6 - 8 hours. If your not able to do the conversion, that adds about another $300.00. Not a cheap endeavor but well, well worth it.
My Polly bushings came pre-collared. That the metal collar that wraps around them. Needed to use an air chisel on the side of the old bushing collar. The angle was towards the way the bushings exit the A frames. The chisel collapsed the collar enough for it to release years of grip, and "pop" out. I also had access to a press that I used to remove the old bushings out of the rearend suspension arms. The new slipped right in.
Do put the new bushings within the freezer for 24 hours before doing the install. Mine came with a packet of silicone grease, (I think), that you slop all over the collar exterior just prior to pushing them in there location. The freezer trick shrinks the whole bushing/collar about 1/64th + - of an inch over the total width. Just enough to make it doable ....
[ Thanks to Gary Couse for this information. ]
Polyurethane Bushings - Full Size
The following is a cross reference for a 1966 full size Olds. It should apply to 1965 to 1970 full size Olds.
I HAVE NOT TRIED THE FRONT-END COMBINATION!!! CAVEAT EMPTOR!!!
I looked up the parts for the C body and the A body cars. What I found was that the uppers and lowers were used on C and A body cars but for different years. After I found the TRW and MOOG part numbers, I cross-referenced these to the Energy Suspension parts. Note that you need the uppers from one set and the lowers from another. The are sold by E.S. in sets that contain uppers and lowers. You would have to buy two sets and use half the parts.
For liability reasons, Energy Suspension sells the sets this way. You buy the complete set for your car. The demand for C body cars is not very great. (How many people owning these cars require these parts? I suspect just a few insane people like myself ;-)
The other unknown issue is that maybe OEM rubber bushings will swap easier that the stiffer polygrahite bushings. I suspect that with rubber, the natural give would provide a greater degree of tolerance. With a stiffer bushing, the tolerances may cause them to fail (crack) where the rubber bushings would not notice... Can someone comment on this conjecture???
I did use the E.S. part #3-3132 on a set of 1964 Ch*velle lower rear control arms. These have been installed in my 1965 98 for about a year and a half. I boxed them before installing the bushings. (I think I used 3/16" steel plate and a 7013 welding rod). The only problem with this setup is that you have to tap the control arms to mount the emergency brake cable holder. I did not replace the upper control arm bushings yet. When I do, I will use OEM rubber bushings. (The GM 4 control arm setup has some built-in play. By boxing the lowers AND installing poly bushings, you run the risk of breaking a control arm or something equally nasty. Aftermarket boxed control arms use heim joints to avoid this problem.)
1965-70 Olds C-body (88, 98, etc.) Front end control arm bushing set Manufacturer Part # TRW upper set 12235 TRW lower set 12213 MOOG upper set K6108 MOOG lower set K5144 E.S. upper set from 3-3103 E.S. lower set from 3-3117 1965-70 Olds C-body (88, 98, etc.) Rear end control arm bushing set Manufacturer Part # MOOG set K5161 E.S. set 3-3132 1965-70 Olds C-body (88, 98, etc.) Front End Links Manufacturer Part # MOOG set K440 E.S. set 9-8118 1965-70 Olds C-body (88, 98, etc.) Tie-rod Boots Manufacturer Part # E.S. set 9-13101
I've purchased some polygraphite bushing sets for my 66 Starfire. They're not on yet, so are not confirmed to fit, but they match the TRW factory spec bushings so they should.
So there are 2 pieces of good news for us big car guys: 1) You _can_ get poly bushings, but have to buy two sets for a total of $135 or so, some parts will be unused.
2) The Hotchkiss rear trailing arms fit our cars. The early ones from 64-67 work on my 66. I believe this combo will also work up to 1970, perhaps later.
So if you want a good handling landyacht, stay tuned. When I get the parts on and confirm that they 1) fit and 2) are an improvement (or not), I'll let you all know the recipe. Kudos to Dan Lacey for the TRW/Energy Suspensions research on this one.
Just thought I'd pass along the details of the conversion of my 66 Starfire bushings from rubber to polygraphite. I'm using rubber bushings in the back since that's what came on the Hotchkiss Cutlass boxed rear trailing arms on both my Big Olds cars. Yes, Cutlass arms on big cars. Go figure. But it works, conclusively.
My good local parts store stocks lots of Energy Suspension parts. Also someone had posted to this list some suggested, though I think, untried, parts numbers for this application.
Anyway, I tried it and found the results very firm. I'm not sure I like it yet, but getting there. You definitely feel the difference and I won't put these bushings on the 98 convertible. I kinda like the sportiness/control aspects for the slightly sportier boat nature of the Starfire. Note that due to the age and mileage on my car some of the lowers had to be tack welded to the A-arms. My experience is that eventually bushing holes wear, sometimes out of round, tack welding is a safe fix.
Because Energy Suspensions doesn't package a kit for the 65-70 Olds 88/98/Starfire, I had to purchase two kits: 1) 3.3117G "GM Front Control Arm Bushings" and 2) 3.3103G "Control Amr Bushings - Front (with 1 5/8' O.D. Front Lower. 73-74 Camaro, Firebird, TransAm, 73 Chevelle, El Camino, 71-73 Caprice, Impala"
I used half the bushings from each kit. Basically what we did at the store was match 'em up against the TRW rubber bushings to be reasonably sure they fit. And they do.
My guess is you could mix'n'match various energy kits to fit Toro's and other unusual applications if you wanted to. Just measure against known good fitting bushings. Olds doesn't seem to have done much in the way of exotic bushings in this time frame.
[ Thanks to Dan Lacey, Chris Fair for this information. ]
Rear Stabilizer Bars
A rear anti-sway bar really doesn't give too hard of a ride compared to heavy springs. The difference if simply amazing. I take curves that I used to brake for without even letting up on the accelerator pedal! Just make sure all the bushings are in very good shape. Also, DON'T use these bars with reproduction biased plied tires. The don't have the grip of a radial for handling and will be overcome quickly.
A panhard bar is the link which keeps a multi-link suspension from moving right and left. A sway bar attempts to eliminate unwanted up-and-down motion at either end during cornering.
I think starting in 1973 all of the A body cars used a reinforced open lower trailing arm instead of a boxed lower arm. The reinforcement was a "pipe" welded into the open control arm with the sway bar bolt passing through it. My 73 4-4-2 with the W-29 handling package has it as well. The pipe keeps the control arm from twisting in a similar fashion to that of a boxed control arm.
This obviously solves the first problem I mentioned, that of crushing the lower arm, but it doesn't fix the second, which is the reduced torsional stiffness of the lower arm negating the effect of the rear bar. Note that the rear suspension design of the A-body cars uses the lower rear arms as a part of the sway bar itself. The result is that the effective stiffness of the bar is not only a function of the bar itself but also the attachment of the bar to the lower arms and the stiffness of the arms. Obviously, adding a bar to a car which originally had none will bring an improvement, however adding the same bar to a car with boxed lower arms will bring an even greater improvement.
Those links are not designed to withstand, because they are not loaded with significant amounts of.... tork. They are pretty much tension/ compression forces, until you add that stabilizer, which adds some bending moments, but, virtually no torque.
You could run TWO of the stock GM small anti-roll bars. When you box up your own rear control arms, use a section of angle iron instead of just a piece of flat stock. This will let you run one bar on the arms and one just forward and below it. This is the cheapest way, as you can often get the stock bars really cheaply. Anything from a GM/RWD/passenger car will work.
If I remember correctly, the sway bar effectiveness goes up as its diameter to the power FOUR, so a 1-3/8" bar has 1.46 times the roll stiffness of a 1-1/4" bar, and 6.1 (!) times the roll stiffness of the stock 7/8" bar, assuming similar metallurgy for all bars.
[ Thanks to Jim Chermack, Ed Binnix, Denney Keys, Joe Padavano,Ω John Carri for this information. ]
Mid Size Cars
Interchange for your Olds:
Olds Vehicle GM Vehicle Notes 1964-1977 A-body (Cutlass) 1970-1981 F-body (Camaro, Firebird) 1978-1988 A,G-body (Cutlass) 1977-1985 B, C body (Delta 88, 98)
Vehicle Year Bar Size 1978-1980 Formula, Firebird 1 1/4"
[ Thanks to Ed Binnix for this information. ]
Full Size Cars
Interchange for your Olds:
Olds Vehicle GM Vehicle Notes 1977-1985 B,C-body (88, 98) 1973-1977 A-body (Cutlass) 1977-1985 B,C-body (88, 98) 1986-1996 B,C-body (Impala) 1977-1985 B,C-body (88, 98)
If you are looking for a rear bar for a '77-'96 RWD GM full size car look at any '77-'84 C car (98, Electra, Cadillac), '77-96 RWD B car (Caprice, Impala, Le Sabre, 88, Catalina, Bonneville), '73-'77 A body (Cutlass, Monte Carlo, Grand Prix), or D car (Cadillac). Don't forget the 77-96 "D" car, the Fleetwood RWD.
Vehicle Year Bar Size
Rear sway bar is easy to add on. The best is the 24mm unit common on the F-41 (handling package) or 9C1 (police option) Caprice. This is also found on various Buicks, Pontiacs and Cadillacs built between '77 and '96. Measure your front bar. If it is 26mm or greater, adding the rear bar is a good idea. If it is smaller than 26mm, upgrade the front bar as well.
While the wheelbase is 116" for both the '73-'77 A body sedans and the '77-96 B body cars, most of the other frame dimensions are a bit different. Some rear suspension parts interchange, but that is about it. The 4 door A body chassis was used for the 2 door B body vehicle. The 4 door C body used exactly the same chassis except it was lengthened 3" (from 116" to 119").
The station wagon differential is wider.
Boxed lower control arms: It is also a good idea to have your lower control arms "boxed". The arms on the A-B-C body cars are identical, up to '94 or so, when Caprice 9C1's of the '91-96 era started breaking the sway bar mounts. GM designed a 'kit' that has a redesigned sway bar mount (mounts through the top of the arm, instead of the U channel plate that fits inside the bar). The kit includes a pair of lower control arms with high-durometer bushings and mounting hardware. I got mine for $60 at the local dealer. You might have to reference the number to your car, My '78 Delta has the same lower arms as the newer Caprices use (astonished the parts guy too).
My '66 88 Apprehender has factory rear sway bar and boxed lower trailing arms. Please note the lower arms are boxed from the factory just like on a 442. I wouldnt advise using a rear sway bar without the boxed arms. Non-factory sway bar cars have hollow lower arms shaped like an inverted 'U'. The factory boxed arms have 1/4 inch plate welded on bottom to close the 'U' plus ribs that extend up into the cavity of the arm to prevent it from crushing under load. I think it would be no problem to have a good welding shop make these modifications to your bars. Would be great if you could show them a 442 boxed arm to go by.
[ Thanks to Fred Nissen, Mike Jones, Martin Thomas, Bryce Smith for this information. ]
Rear Control Arms
Don't box the rear upper control arms, or use stiff bushings there. By stiff I mean polygraphite. Not stiff would be OEM rubber bushings. DO NOT BOX the uppers. It "may" be wise not to use stiff bushings on the uppers if you use stiff bushings on the lowers. This 4 arm system was designed to flex a "little". Making everything too stiff may cause something to give (read: break).
The boxed lowers (uppers, too) are stronger because of a metal plate welded (or cast with the arm) across the U-section. The metal plate is welded on the bottom of the arm, over the valley formed by the "U". Hope this helps. Check out my ASCII art below:
That is a cross-section of a regular control arm: Here's a boxed one: ______ / \ | | | | / \ ========== ______ / \ | | | | / \ ==========
If the latter, non-boxed control arms, make your own......it's cheaper. Start by tack welding some pieces of pipe inside the control arm perpendicular to the already existing holes for the sway bar bolts. That way, when you tighten down the bolts, the control arm won't crush. Then weld a plate across the bottom to finish the "box". The factory used a single piece of stamped steel that did the same thing, box the arm and provide anticrush support versus the bolts. The two steps I mention will be just as good as factory (that's all the original boxed arms are), and if your current arms are in good shape probably cheaper than buying used arms which could be rusted all to hell and need new bushings anyway.
Lower control arm Interchange for your Full-size Olds:
Olds Vehicle GM Vehicle Notes 1965-1970 B,C-body (88, 98) 1964-1967 A-body (Cutlass)
Lower control arm Interchange for your Mid-size Olds:
Olds Vehicle GM Vehicle Notes 1964-1972 A-body (Cutlass) 1964-1972 A-body (Vista) 1964-1967 A-body (Cutlass) 1965-1970 B,C-body (Vista)
Upper control arm Interchange for your Full-sizeOlds:
Olds Vehicle GM Vehicle Notes
Upper control arm Interchange for your Mid-sizeOlds:
Olds Vehicle GM Vehicle Notes 1964-1967 A-body (Cutlass) 1964-1972 A-body (Vista)
While boxing the arms is a good idea, it is definately not a cure-all solution. While what you said about flexing is correct, your lack of traction off the line is a function of suspension design, tire compound, etc ~not~ control arm flex. Unless you are leaving two dark black rubber tracks behind you when the tires are spinning, you are not loading the rear suspension hard enough to make control arm flex a limiting factor. The fact that this guy said to stay with the smaller tires tells me he is a little "off" since the biggest change you can make on any car is the tires. Going as wide as possible with your tires is your best bet, as long as they fit. Boxing the lower arms and adding the poly bushings will help control side to side movement of the rear axle under cornering which will allow you to mount the largest tires possible.
The other factor here is weight transfer. Relocating the battery will help but lowering/stiffening the suspension will do the opposite. I wouldn't worry about breaking the control arm mounts but the Hotchkis arms do come with triangulation braces for the lower arm mounting points. These mods will help the cornering more than the launching and won't have any real effect on ride.
I bought SSM bars for my 1972 Cutlass and they are great. They launch the car much better because they don't twist, they lift. They are boxed and have steel bushing inserts so they have to greased every time you grease the front, unlike stock which have no grease fittings for the rear. The SSM bars also help when cornering because they keep the car from swaying. YOu can still use the stock sway bar also because they have the holes drilled out already. Easy to install just have to drill 2 holes, everything else is a bolt on.
Also bought the Jegs (JEGSTER) adjustable rear upper control arms. They are tubular and have solid steel inserts also. Have not installed them yet but my buddy has and it improved his 60' times. Plus you can adjust pinion angle and the rear end will not deflect as much as stock (rubber) would and the tubular arms are MUCH stronger.
[ Thanks to Jason Adcock, Bob Handren, Randy Geisel, Jim Chermack, Kurt Shubert, Mike Bloomer, Dan Lacey, Peter Landowski for this information. ]
Install the best gas shocks you can get. Their dampening ability better matches the new bushings than anything obtainable stock.
1965 - 1967 Front Shocks::
I replaced the shocks on the 1965 today, but not without the usual hassles. The first obstacle (and the one I thought was going to be the "major") was finding the things for the front. Every parts store I went to had the rear shocks, but had no parts listing for the fronts. After some hesitation, I started opening boxes and comparing the originals to many different models (mounting provisions, overall diameter, and piston stroke). I finally found that the 1968 - 1972 model was completely acceptable.
Upon talking to an ASE certfied "parts specialist", I found out the reason for the lack of a part # for 1965 - 1967 front shocks. GM had not, for some unknown reason, ever released the specifications of the front shocks to the after- market so they could design a shock for these three years of "A-body" cars.
I used the originals as a means to measure for the correct fitting shock. The stroke (travel) of the aftermarket shocks are identicle to the originals in every way, except that the overall diameter of the new shocks are thinner.
Although the 1968 and up shocks will "fit" your 1965, the problem is the 1968 and up shocks have a shorter extended length. This will only present a problem should you decide to do some off road style driving ala "Dukes of Hazzard". Which of course I doubt you will, but keep in mind when the front of the car is on a lift or on jack stands, the shorter travel of the shocks will mean they are holding the weight of the tire, suspension, brakes, etc. Rather than allowing the full travel of the suspension. This could cause a major failure of the shocks since they are not designed to carry a load in this manor.
Personally, I wouldn't worry about this, since I have seen a lot of cars that have this situation and never have a problem with it. It is actually fairly common to see the shock holding the suspension from acheiving full droop due to lack of shock extension. Whether this is from OEM spec or aftermarket need to have one product that covers many different applications I don't know. As far as the load from jacking the car up I have never seen a shock fail due to this but the jarring effect on the shock would be much greater from a rapid extension of the suspension in, say, a wheelstand or a jump. At that point shock failure would be the least of your worries. If it does worry you, though you can utilize an old drag racers trick which is to use straps connected between the frame and the lower control arm to limit suspension extention. Just a thought.
[ Thanks to Gary Couse, Collyn Eastham, Mike Bloomer for this information. ]1978 - 1988 G-body:
The Monte Carlo mailing list suggest that the Monroe Sensa-Trac shocks are the best bang for the buck. Bilsteins and Konis were also discussed, but it depends on what kind of handling you want and how much you want to spend. Most list members, myself included, gave the KYB's a thumbs down.
[ Thanks to George Dumpit for this information. ]Coil Over Shocks
Coil-over shocks are available from several US manufacturers (I recommend ProShocks, we use them on our stock car) and springs can be purchased in many different rates (I use Afco on the stock car, and their rates are available in many different lengths, so you can tailor the rate and the length you need) so these don't have to be that expensive, although they will cost more than the typical shock and spring setup.
[ Thanks to Ken Snyder for this information. ]
Call MOOG at 1-800-325-8886 and ask them what will fit your car. They can probably give you more than one option.
For example, I have a '65 98. The original spring is 370 lbs per inch of travel. They don't make these anymore, so, when you go to the local parts store, they will say "They don't make those anymore. I know a place that can get what you need, but it is a special order and costs ..." You get the idea...
The MOOG technician tho went on to say that they make 2 other springs that would give me the same ride height in 390 and 480 lbs/inch. Once they give you the part numbers, you can go anywhere and order them.
Interchange for your Mid-size Olds:
Olds Vehicle GM Vehicle Notes 1978-1988 A,G-body (Cutlass) 1978-1981 F-body (Z-28)
Interchange for your Full-size Olds:
Olds Vehicle GM Vehicle Notes 1977-1985 B,C-body (88, 98) 77-96 B,C-body (Police Caprice)
[ Thanks to Dan Lacey, Bob Barry for this information. ]Cutting:
Don't cut the coils until after you have made all of your major weight adding/reducing modifications. Like engine and trans swaps for example.
Begin by cutting a 1/2 coil at a time with a cutoff wheel until you're happy. The good thing is that springs are cheap; it's the labor that's the pain.
[ Thanks to Bob Barry for this information. ]Lowering:
A spring and a torsion bar (a la Mopar designs) are essentially the same thing. One is straight, the other is bent into a coil. If you shorten the torsion bar it will be more difficult to twist it because there is less material to twist. Cutting a coil accomplishes the same thing and it will be stiffer. Springs are rated in lbs/in of deflection. Cutting the coil will increase this value. An easy demonstration is to take two paper clips. Leave one full length, cut the other in half. Bend both so that you have "handles" at each end. See which one is easier to twist. The shorter one is a lot tougher. Also, the more coils (the longer the torision bar) for the same diameter wire, the softer the spring. So cutting one coil from a spring with 10 twists will have less effect than cutting one coil from a spring with 8 twists.
Safety note: NEVER HEAT COIL SPRINGS TO LOWER A CAR!
Springs are tempered steel. Heating destroys the temper and can make the metal brittle. It can definitely ruin your day (and maybe your life) if you hit a bump and the spring breaks. The only safe methods of lowering are cutting coils and dropped spindles. (I haven't heard of anyone "channeling" a modern car lately.) Of the two, dropped spindles retain the factory designed front end geometry. Buy spindles only from reputable well known companies. Again, your life and well being could depend on it.
(For those age challenged folks who don't remember or know the old customizing methods of the 50's, channeling is where you make channels into the car/truck body so that it can be reinstalled on the frame at a lower position. This leaves the frame, suspension and drive train in the stock configuration. It's a very big job frequently requiring a new floor pan, modified fire wall, etc. to clear the trans, drive shaft and engine. Not easy or cheap but it really changes the appearance of the car dramatically. Appears to be a lost art these days.)
Channeling has now been taken up by many low-riders and other custom cars as "Body Dropping". It costs a pretty penny to get this done now. I think about 3,000.00 for a 60's cutlass (probably the easiest). Looks awesome though.
[ Thanks to Brett Wilson, Bob Handren for this information. ]
Traction / No Hop Bars
The coil spring traction bars are actually upper control arm positioners. You don't see 'em unless you crawl under the car and actually look way up there.
They do make slapper-style bars for the GM coil spring A-bodies. I've heard they work great but would prefer the stealth of the upper control arm relocation type of traction device.
Traction bars are only for leaf spring cars because a leaf spring car the springs control the "bounce" and locate the axle. In a high hp car, the spring will twist between the axle and the front spring eye. What the traction bar does is make a solid link between the axle and frame when the axle tries to twist.
As far as coil spring cars, traction bars wouldn't do anything since you already have solid suspension links. Equivalents would run the gammut from ladder bars to lift bars and hop stop bars. Ladder bars are just that though I haven't seen them around for years. Basically they worked just like on a drag car but they didn't work all that great.
Lift bars and/or hop stop bars or upper bar relocators all work by revising the stock 4 link geometry. All the upper echelon drag cars with tube frames run 4 links and the GM 4 link can be made to work just as well. The lift bars usually replace the bottom bars and are popular for 5.0's (different susp design) but I think I have seen them for 64-78 A bodies.
The hop stop kits and upper bar relocators move the axle mount for the upper bar higher moving the instant center of the 4 link closer to the center of gravity of the car. With proper tuning, the factory 4 link can get enough traction to launch very hard (pull front wheels off the ground w/10" slicks) but to do so, it usually requires strip only modifications to soften up the suspension for wieght transfer. As far as looking good, most cars I've seen with traction bars look riduculous because it is actually rare to see one that's adjusted right.
[ Thanks to John Pajak, Mike Bloomer for this information. ]
Eliminating Rear Suspension Play:
I've been thinking about a Panhard rod, or better, a Watts linkage for the rear axle of my '72 Supreme. As you say, those control arms don't do much to "control" sideways movement of the rear, given that almost half the weight of the car is back there, and there is a long lever arm acting on nothing but the bushing compliance to hold the rear in place against sideways forces. Worse yet, in a turn when there are sideways forces on the axle, that sideways preloading on the rear control-arm bushings will make them tend to bind and resist suspension travel up and down, thus worsening handling in bumpy turns. Heavy-duty control arms and poly bushings might help, but don't seem to address the real problem, especially since polyurethane should not be used where there are angular misalignment forces like this - I've read that it tends to undergo plastic flow and deform permanently, unlike rubber, which regains its shape. So it might be firmer at the start but more wiggly-waggly once worn.
My car waggles its behind from side-to-side disquietingly every time I go over a speed-bump or pothole, and while it's entertaining for a short while to have a car that does the Macarena at every opportunity, it makes me feel sea-sick and gets annoying very quickly. Now I really appreciate the good engineering that went into my '73 Road Runner leaf-spring rear - no wheelhop, no sideways waggling.
Actually the stock setup does offer some inherent resistance to lateral movement of the rear axle and this is due to the angling of the upper control arms. I had similar problems as you described with my 72 along with approximately 2" (1" to either side of center) of lateral movement during hard cornering. My car still had the factory rubber bushings and, though they looked fine, replacing them made a world of difference. I stayed with rubber bushings, but the only explanation I could come up with was that over 25 years the original rubber had just lost it's elasticity.
Maybe something you ought to consider if you haven't already. The panhard rod idea is something I was discussing primarily to allow you to run the widest rear tire possible. The Watts linkage is the hot setup but it has some major drawbacks when talking about A bodies. First is that it takes up much more room than a panhard bar, which would interfere with the shocks and exhaust. Next is the actual mounting of the center pivot to the rearend. With a 9" ford type rearend you can simply weld the pivot to the center of the rearend cover (many cars that come with this setup stock have it like this) but with a GM rear with removable cover this won't work and so more hurdles. The amount of advantage you would gain with a watts link over a panhard rod is just not worth the effort and expense it would take to make it work. Keep in mind that with a long enough bar you can easily set up a panhard bar to accommodate over 5" of wheel travel with no more than 1/4" of lateral movement. Just a few thoughts to ponder.
The Panhard setup lets you run a single control arm on the top, but it can have solid bushings.
I suspect you're thinking of a Watt's linkage, which has the pivot in the center and a bar on either side which is attached to the frame. A panhard rod is a single long rod which goes from the frame on one side to the axle housing all the way on the other side. The Watt's linkage is the superior design, as it truely does keep the rear end centered. The panhard rod actually travels in an arc, with the result that there is some side-to-side motion of the axle as it travels up and down. By making the panhard rod as long as possible and as horizontal as possible with the suspension at normal ride height, this side-to-side motion is minimized. I believe this configuration was used on the last-generation F-bodies, for example.
You are correct in that the basic design of GM's four-bar suspension does provide lateral restraint through the angled upper arms. Deterioration of the rubber bushings over time will cause it to loosen up. I would not use anything other than OEM-style rubber bushings, however, as the motion of the suspension requires these bushings to rotate side-to-side as well as up and down. Urethane bushings will lead to binding in this configuration (especially on the lower arms). The only viable alternative are the aftermarket arms which use metal rod ends with ball pivots.
There is a solution!! INSTALL A REAR SWAY BAR! The U shape of the bar, bolted to both rear control arms, reduces the tendency of the axle moving sideways to practically nothing.
Visualize the setup from above. The rear bar bolted to both arms really makes it stiff: ASCII art follows of the sky view:/ \ /--------------\ ==
This is absolutely right, but there is something that gets overlooked. During extremely hard cornering, a stock sway bar will still allow lateral movement. You could go to a thicker bar, but then you affect your handling. If your cornering hard enough to cause this movement, then you don't want to arbitrarily jump to a larger bar because on the effect it will have on handling.
Have you looked at the possibility of getting an F-body rod from a wrecking yard? Would keep the costs down and incorporate OEM-style rubber bushings. Also, doesn't the F-body rod have a bend to clear the center section of the rear end?
I'm sure that you're aware of the need to ensure that the bar is in the horizontal position at normal ride height to minimize the lateral motion during suspension travel. You'll need a tall bracket on at least one end of the bar - maybe the F-body part can be adapted.
The only other concern would be binding between the panhard rod and the upper control arms. You'll need to look at this, as most panhard rod applications use parallel control arms.
In the F-body anyway, there are two lower control arms to control fore/aft movement of the axle, a torque arm to control rotational movement (of the axle tube), and a panhard rod to prevent lateral movement of the axle.
FWIW, in a Grand Cherokee, the front and rear axle both use 4 control arms (each), plus a panhard rod each. The arms are much more parallel than the arms in GM 4-link rear suspensions, but there still are angles between the upper and lower arms. I guess that as the angle decreases, so does the binding?
Yep. Do the trig and you'll see that the off-axis rotation decreases as the arms become closer to parallel. With rubber bushings, some off-axis compliance is obviously available to accommodate this rotation. Stiffer (urethane) bushings make this off-axis compliance much stiffer and thus lead to binding.
Your correct, but as you bring the upper and lower arms to parallel you will loose your instant center and any hope of getting traction. The angles of the upper and lower arms when viewed from the side give you your instant center (by drawing a line out through their pivot points) and by moving this you can affect how well the car loads the rear tires when you punch it.
This is why relocating the rear upper arm mount upwards will eliminate wheel hop and give you a better launch. The F body suspension is one step up from leaf springs which is about the worst design you can get (yes, I know you can make them work but it doesn't make it the most efficient/best design). In drag race terms the torque arm in a F body equates to a ladder bar which is deficient in its ability to load the rear tires as hard and it also travels in an arc which will cause even more binding. Now, I remain unconvinced that a properly fabricated panhard rod with a factory 4 link will cause enough binding to be noticeable. The stock suspension will allow lateral axle shift of well over an inch. A good panhard rod will only take the axle through 1/4" of movement which bushing deflection will easily accommodate. Maybe I'll just have to scrounge up some steel and fire up the welder.
I still believe that those people that are have problems with their rearends doing the macarena must have a bad bushing(s) to allow it to move that far. Maybe just blown shocks or wore out springs, but nothing that would cause you to go as far as modifying the suspension. The only reason I ever researched it was to allow me to run the widest tires possible without worrying about rubbing the fender wells.
The front control arms might move slightly back and forth horizontally due to application of the brakes, but they shouldn't! This uncontrolled motion is what causes handling problems. This is unlike the four-link rear suspension, where what I'll call a twisting motion must take place to allow the suspension to articulate. In other words, if the front bushings were solid metal and only pivoted about the A-arm bolts, the suspension would work just fine. The same is not true of the rear suspension, however, where the rubber bushings must also deflect about an axis normal to the bolts in order for the suspension to move through it's full range of travel. Note that here I'm also assuming that there is no clearance between the hole in the bushing and the bolt. Note also that the oval bushings used in the lower A-arms of some A-body cars are designed to deflect rearward slightly under high impact loads (like hitting a pothole or rock). In this case, handling precision was sacrificed for ride comfort.
I was oversimplifying to try to make the concept clear. You're right, there are lateral forces from braking, and plain and simple from the weight of the car. But these forces are not as bad as what happens with the rear control arm bushing - visualize a 2-foot-long lower control arm, pivoting on one bushing, with something like 1/5th of the cars weight pulling it sideways at the far end! (somewhat overestimated, assumes 40% of car weight on rear wheels, 1-G cornering, and two control arms sharing the sideways force to make 20% of the weight of the car on each arm).
The front control arms are triangulated, which is why the forces are not so bad - rather than twist one bushing, the forces are turned into compressive forces on two widely separated bushings.
Once again old Mopars have a wonderful design here - the lower control arm is triangulated by a strut-rod that runs forward at an angle to the cars K-member, in effect resulting in a lower control arm about two feet wide at the base; just like standing with your feet far apart, this braces the arm very well against braking forces.
[ Thanks to John Carri, Mike Bloomer, John Pajak, Jason Adcock, Joe Padavano, for this information. ]
A true ladder bar setup is not necessarily the best setup for a true street-strip car. While the forward-rear location of the axle is excellent, you need a panhard bar to locate it side-to-side. Without one, your car's body will fall off the side of the road without the axle attached the first time you take an off-ramp. The stock 4-bar setup is an excellent street/strip suspension. If the super-street guys can get their cars into the 9's and even the 8's (figure 700+ hp) on the stock-geometry suspension, you should be able to plant a measly 500 hp with it.
[ Thanks to Bob Barry for this information ]
There's a folk story about a guy who sheltered under a tree in a forest when it started raining. After a while the tree was soaked through and it began to drip on him. "No problem", he though to himself, "the wood is full of trees, I'll just move to a new tree each time the one I'm under gets soaked through".
Unfortunately all the trees get soaked through at roughly the same time, so our friends bright idea didn't work too well....
The problem with front ends is that they are like the trees in the wood - there are a *lot* of parts in the front steering linkage, and they all tend to wear out at about the same time! This is why so many companies sell complete "front end rebuild kits" rather than just individual ball joints or bushings or whatever.
All the parts you changed undoubtedly helped, but you may still have wear in the control arm bushings, idler arm, tie-rod ends, and the actual steering gearbox and/or rag-joint.
Try jacking up the front end of your car, grabbing one front wheel, and trying to wiggle it back and forth. If there are worn parts in the linkage you'll be able to wiggle the wheel, and you'll also notice that the other wheel doesn't wiggle as much as the one you're grabbing - - there is lost motion in all the worn bits along the way. Before I rebuilt my '72 Supreme's front end I could wiggle the drivers side front wheel back and forth about a quarter of an inch without any motion at the passengers side wheel!!
It's expensive, and if you do it yourself, tedious and time consuming, but once you replace all the worn parts your car will handle better; to get more steering feel and to make it handle as well as possible, have it aligned after you're done. Ask the alignment guy to set the toe to about 1/16" toe-in, set the camber to about -1/2 degree, and set the caster to about +3 or even +4 degrees. That much positive caster will give you much better steering feel and slightly higher steering effort, usually a good thing with the usual overboosted power steering on our Olds', and it will also make your car track straighter on the freeway.
I've just got through doing all of this on my car, except for replacing the steering gearbox with a rebuilt fast-ratio one, and it tracks much straighter and has better steering feel than before, even though there is still play in the steering gearbox.
[ Thanks to John Carri for this information. ]
Have a machine shop or auto parts store remove the bushings from the control arms. This makes the job alot easier, and you don't have to worry about damaging the A-arms. The $10 each is worth the price just to eliminate this bit of aggravation. Then all you have to do is remove the ball joints, sand blast and detail.
The goal is to wedge the tapered bolt out by jamming the fork between the centerlink and the idler arm, causing the tapered bolt on the centerlink knuckle to pop out of the taperd hole in the idler arm. But unless you are very careful and the boots are almost new, using the pickle fork will tend to rip up the rubber pieces which is probably why I have never seen one in any of the GM manuals. As you seem to be from California, Trak Auto will lend you a Pitman Arm Puller which can usually be used to pop the other suspension knuckles apart. I have a little tool that I bought when I lived in Canada that slips under the rubber boot and uses lever action to break the joints free, works very well but I have not seen one down here.
Something that took me a while to figure out on my pickle fork is that it has one side that is flat and the other that is wedge shaped. It works best if you put the wedged side toward the piece that you are trying to move.
BTW I think you can buy replacement boots from the parts store and mail order so you can avoid replacing the joint.
To avoid stressing the joint and components and damaging the ball, socket and bushing, use a brass hammer or brass drift punch to seperate the tapered stud from the tapered hole. Pound on the side of the casting containing the tapered hole, using the components weight to cause it to seperate from the joint. It takes time, but you won't break or damage anything.
[ Thanks to Lloyd Ferguson for this information. ]
Rear Control Arms
I can only say no matter what you do it is going to be a good wrestling match. I unhooked both shocks and controll arms at the same time. You need all of the free play you can get. Hook one side up at a time. Get the bushing close to bolt hole, and use a screw driver to line the hole up the rest of the way. Then you can put the bolt in. Jack up one side of the axle, and let the other fall down. This should help you get the angle you need. Are you doing the upper arms as well? If so just drop the whole rear end out. Then hook up the lower arms first (bolt them to the body first then put the diff on), and jack the diff into place and hook up the upper arms. I dont mean to tell you something you already know, but the rear springs only go in one way also.
[ Thanks to Steve Harris for this information. ]
You can make things much, much better, but it will take time and money. My Supreme was so "floaty" when I got it that it was quite scary to drive, it's much better now but I still have a long way to go. Here are some of the things that can be done to improve the steering feel:
1) Adjust the steering-gear for minimum free-play. There is an easy adjustment for the sector/worm spacing, and a difficult one for the axial end-play, even just the easy one by itself will make a difference, and cost you nothing, so it's a good place to start.
2) Align the car to have much more positive castor. Up to about 4 degrees of positive castor (top of spindle further back than bottom of spindle) will greatly improve road-feel. You'll need an alignment guy with his wits about him to do this, the usual "its not in the computer!" droid won't do. (I haven't done this yet because I still have some worn suspension parts to replace first)
3) Get big fat swaybars on the car. I have a 1 1/4" front bar off a junkyard 1981 Trans Am on my Supreme, it cost $10 plus $25 for the poly endlinks and bushings to mount it from Energy Suspension. You can use the front bar off any 1970 - 1981 Camaro/Firebird, but the Trans Ams have the fattest ones. The aftermarket also has bars in many sizes, but they cost *much* more. To get good handling you need a matching rear sway bar. (I still don't have a rear bar and my car understeers or "pushes" in turns).
Now we're getting into more expensive things to do:
4) Get bigger wheels, and tires with shorter sidewalls. I went from 14" wheels with 215/75/14 tires to alloy 16x8 wheels off another late 80's Firebird with 225/60/16 tires. They are the same diameter as the 14" tires, but the shorter sidewalls make the car much more responsive to steering inputs. I paid $120 for my used wheels (through the Recycler, local free ad. paper), about $200 for my tires, and about $50 to have them mounted on the rims and balanced.
5) Get stiffer shocks, and if possible stiffer springs. I have KYB Gas-A-Just shocks ($120 for all 4) and Hotchkis springs ($250 approx) on the car, and they make a significant improvement over the mushy stock shocks and tall, floppy, stock springs. Global West, HO Racing, etc, all sell spring/swaybar packages, and it is a good idea to use the recommended swaybar/spring combination from one manufacturer.
6) If any part of the front end is worn, replace it. This includes the idler arm, tie-rod ends, ball-joints, bushings, & centre-link. (So far I've replaced lower arm bushings, ball joints, and idler arm on my car.)
7) If you really want better handling and road feel consider converting to taller spindles and bigger front disc brakes. There's some info on this in the FAQ, and much more in the heads of other listees. I'm collecting parts for this swap now.
8) If you still have any energy or finances left, swap in a higher-effort, fast-ratio steering gearbox. Info on this too exists among listees and on the FAQ. The gearbox can be scrounged from a junkyard (with many caveats) or obtained from Global West, Lee Steering, or many other rebuilders. Cost is from $200 to $500 for a rebuilt unit depending on whom you buy it from.
My Supreme is gradually learning handling manners (I now have Hotckiss springs, KYB gas-a-just shocks, and while I save up the money for matching Hotchkis sway-bars I'm using a 1 1/4" front sway bar off a 70-81 Pontiac Trans-Am. 16x8" wheels with 225/60HR/16 tires are waiting in my garage to go on this weekend. At this point my car handles much better than it did when I got it, and I even outdrove a Civic on the twisties recently, but my car is no threat whatsoever to Mustangs, Camaros, and Corvettes in the turns. Yet. But it will be someday...)
[ Thanks to John Carri for this information. ]
Eliminating Wheel Hop
Be careful with wheel hop. It tends to do some real damage in the long run. One method is to use Anti-hop bars. They take the place of your upper control arms and put the rear at a better position for hard accelleration
If you don't want to go for anti-hop bars, you can put air bags inside the coil springs. They help alot. Get rid of air shocks if you have them. Radial tires tend to bounce more than bias ply tires.
Also if your cars' rear control arms have old worn out bushings, that doesn't help either.
Wheel hop can be prevented without big bucks, just some attention to details. The over riding consideration = If your tires don't break loose, they can't easily hop!
1. As noted, the rear suspension bushings need to be in good shape and a wild rear stance won't help either. Low or high! Screw up the dirveshaft/pinion angle and you'll get more than wheel hop. Like lots of broken u-joints. If the front joint lets loose and you don't have a driveshaft loop to retain the thing, have you ever seen a car do a pole vault? I have and it ain't pretty.
2. Air shocks, in my experience, are good for only one thing - jacking the rear or leveling with a load. As a shock absorber they are miserable. Get some good HD shocks, a 50/50 valving or near has worked for me for over 40 years.
3. Get a set of Air Lift air bags and put them in the rear springs. This stiffens up the rear suspension, allows adjustments for load and most importantly allows you to preload the right side to reduce wheel spin. As a start try about 35 lbs in the right bag and 5-10 in the left. A couple years ago I bet a list member he could get both tires to spin pretty near same amount without a posi unit. He did it, it worked, his buddies refused to believe he didn't have a posi. It works like gang busters. A posi is many times used as a crutch for a lousy set up or poor tires.
4. Run some good tires! Either slicks or the newer drag radials.
5. Unless you are looking for that extra few hundreths at the drag strip, you don't need "no-hop bars" or any of the other fancy adjustable expensive stuff.
6. If this sounds too simple or you don't want to believe me, check out the Hot Rod magazine of about 4-5 months ago. There was an article on really fast street type cars. There were several GM "A" body 64-72 cars described in there. One in particular was an El Camino that ran 10's - with a basically stock rear suspension!
[ Thanks to Hot Rod Harry, Bob Handren for this information. ]
While I can't give you any resonance numbers, I can tell you what I've seen work and some discussions I've had with Ken Snyder on making a competent handling A body for SCCA type racing. The most important thing is to eliminate the C channel in the center of the frame. This is what allows most of the flex. While it would stand to reason that the body of the car would make up for this section directly under it, keep in mind that the C channel starts right under the front edge of the doors.
Between that point and the front of the body section there is only one body mount per side. This ends up acting as a pivot point, and allows the C channel to flex with resulting movement seen in the very front of the car. While poly body bushing would help, you are still only relying on the front fenders to reinforce the front section of the frame to make up for the C channel. The solutions we came up with for stiffening up the structure was to first box the C channel (though with the recent talk of convertible frames, this seems like a more elegant and factory looking solution).
The next step would be poly body bushings. The final amount of stiffening would need to be something along the lines of running tubing from the firewall to the core support. With a bit of work I believe that these could be run under the fenders and be near invisible. The result would solve all of the identified chassis stiffness problems with minimal cost and without making major modifications to the vehicle. This would also give you the solid foundation you would need to do some real suspension tuning.
[ Thanks to Mike Bloomer for this information. ]
1964 - 1972 A Body
The early A-bodies have a weakness in the forward attachment points of the control arms, regardless of what control arms used.
I have a little insight into swapping spindles on the 64 to 72 A-bodies, as I have an asphalt circle track 1971 Cutlass 'S', "Grace". Now what we did as far as the entire swap would not only be impractical (weight jacks and relocated shocks), but some of the things might be something to consider.
In our Sportsman class, we have to use the stock lower control arms, but the spindle and upper control (A) arm are whatever we want. Right now, we're using a set of B-body spindles from the mid-70's. They are tough as nails, plentiful and with a replacement of the lower ball joint can actually lower the car -- that's done with an threaded insert welded to the top of the arm and a Chrysler ball joint, it sets the spindle higher than usual.
The upper arms are tubular off-the-shelf stock car items, and are bolted to brackets welded to the top of the frame in about the same place as the original mounts, only higher. This makes for a better angle (or lack thereof) on the upper arm. I think this (raising the mount) could be done with bolt-on parts and some high-strength hardware, then just select the length of arm you need to get the right geometery on the front end.
If you don't mind spending the money ($157 each), Coleman Machine has a set of spindles that would lower the car and use stock B-body rotors and brakes, or rotors they sell that retain the 4 & 3/4" A-body pattern. We use the 5" pattern since the rear has that pattern as well (F-word 9" rear end) and also uses the same calipers front and rear.
Sometimes the racing market has things that might come in handy on the street. When I "upgrade" the 1970 C/S SX there will be a lot of stock car / road race parts on her.
[ Thanks to Ken Snyder for this information. ]
1965 - 1970 B, C Body
My 1966 98 convertible is set up as follows, most of these tricks will work on 88's and 98's from 1965 - 1970. In 1971 they changed the whole front end susp. from ball joints to steering knuckles.
Swapping generalities: 88's and 98's used the same A Arms (upper + lower) from 1965 - 1970. There were two different spindles depending on whether or not you have disc or drum front brakes. That's the major difference. If you do swap from drum discs (highly recommended) you'll need: 15" wheels, dual master cylinder and adjustable brake proportioning valve. And, of course front disc spindles, rotors calipers, brake hoses, etc. Also be sure to get the 70 disc setup, by then Olds had settled on the corporate one piston system. Rotors are rare (does anybody have a good to great set to sell?). 1971 calipers will fit 1970 backing plates with just a little filing.
I'm using stock rubber bushings with my car because it was designed to ride that way, and I'd heard of the dreaded squeaks. I've experienced 'em too since I have polyurethane on the standard front sway bar. Since greased and quiet now. I can't imagine graphite impregnated wouldn't work as well if not better. Prob'ly a good idea.
KYB shocks are one great way to go for front shocks, perfect balance between control and smooth ride. As noted in this bandwidth before I've beefed up my Lower A arms with some welded in rebar since each side has broken on me right at the ball joint (they just weren't designed to go 300K miles...). The inner lower A arm mount points seem to go out of round over the years and then you get that funny clunking sound, if you get junkyard pieces look out for this.
When I pulled my front & rear suspension members, I had each piece magnafluxed and checked for cracks. No problems there (thankfully) so now I can go 75 mph+ and not worry about pieces going and breaking on me. This is not cheap, but you'll sleep better. Boxing the rear control arms sounds great to me, I'll have to think about that.
[ Thanks to Chris Fair for this information. ]
To recap, here's what the car has now:
- 16x8 Firebird alloy wheels, 225/60/16 tires front and rear
- Hotchkis coil springs, poly spring isolators
- poly front control arm bushings, upper and lower
- 1 1/4" front sway bar from '81 Trans Am, with poly endlink bushings
- Boxed rear lower control arms, with poly bushings
- 1" rear sway bar from OPG
- Front suspension converted to B-body tall spindles for better camber curve
- 12" 1LE front disc brakes
- Koni adjustable front shocks
- KYB rear shocks
- New balljoints
- New tie-rod ends
- New idler arm
- New centre-link (drag-link)
So how does it feel? Much, much, much better than stock, for starters. The car tracks truer on the freeway, makes quick lane changes with aplomb, and while not exactly eager on twisty roads, is at least competent now. When those crazy unexpected emergency stops on the LA freeways occur, Roger now stops straight and true, and feels like he has some braking power in reserve (I haven't locked them up yet). The brake feel is still just plain lousy, though, and I plan to do more work on this in the future (there is too much travel before the brakes kick in, the pedal never gets firm enough, and there is little feel to tell you what the tires are doing as they approach lockup).
The combination of the Hotchkis front springs and taller B-body spindles dropped the front of the car about three inches, and the back about an inch. The slightly nose-down attitude improves my view over that long hood quite a bit, and I can now see out of the rear glass - formerly the upper edge of the rear glass was too low, and cut off my vision to the rear if I sat up straight in the car (I'm 6"2" and have an unusually long back for my height).
Of all the changes, the conversion to the B-body spindles provided the most dramatic improvement to handling. Without the conversion, the camber change with wheel travel on the front suspension is so poor as to be comical, really, and points out loud and clear that good handling was not a design priority for the chassis engineers who developed it. After the conversion, not only do the tires do a much better job of staying upright on the road, but the altered roll-centre meant that the car rolled less with no sway bars at all than it did stock with the stock front 7/8" bar!
Unfortunately, this conversion was also the most complicated and difficult of all the handling upgrades I've done. There is quite a lot of partial information on this swap out there on the Web (try Mike Bloomers page for a start), and I have written a pretty comprehensive document on the conversion process as I went through it, which will soon be up on Thomas P. Smiths' web page.
Next in order for dramatic improvements was the front and rear swaybars. Then, going to the fatter tires with their shorter sidewalls. After that, the springs and shocks.
What would I do differently if I were to do it over? Well, I would use a stiffer rear sway bar than 1", as the car still understeers. I know that HO Racing and Herb Adams both make A-body rear sway bars fatter than 1", and someday I might step up to one of them. Also to save some money I might have gone with the 11" F-body front spindles and brake rotors rather than the 12" B-body spindles and 1LE rotors. Even if I went with 12" rotors I would use B-body rotors redrilled for the A-body bolt pattern rather than pay through the nose for the 1LE rotors, as I did.
Bottom line, I won't be outcornering any Corvettes for sure, but the car now outcorners my wifes Mercury Tracer, my former Mitsubishi Colt (an era of car ownership I don't care to even talk about, driven entirely by purchase cost and good gas mileage!), and most front-wheel drive Japanese cars I've driven. The car feels competent on the freeway on the way to work; the brakes finally have enough capacity to halt nearly two tons from freeway speeds; the firm springs and shocks have put an end to that wallowy, mushy feel on bumps and potholes; and I spent less on all this than I would on have on anything but the very cheapest used fwd 4-cylinder econobox.
A complete writeup on the B,C,F,X-body spindle swap conversion is at: http://home.earthlink.net/~cjcarri/brkswap/brkswap.htm .
[ Thanks to John Carri for this information. ]
1973 - 1977 A-Body
I'm not sure about not stock control arms and such, but H-O racing and herb Adams make parts that will fit. On my 1973 I've got the PST polygraphite rebuild kit put on, (new bushing, steering linkage, and ball joints) H-O springs, which are a bit stiffer than stock heavy duty springs, Herb Adams adjustable 3-way adjustable shocks, and Herb Adams sway bars, 1.3" in the front, 1.5" in the rear.
I still need to get some better tires than the 205/70R14 Radial T/A's I'm running, but it corners extremly well, and doesn't bottom out like it used to. A note on the sway bars though, the front one is mounted with spherical rod ends and is a bit more difficult to install and adjust than the stock set-up. PST sells a 1 1/8" front sway bar with the stock ends, and I would probably go that way if I was going to do another car.
[ Thanks to for this information. ]
1977 - 1985 B, C Body
As far as handling, I'm assuming you've already got front and rear sway bars; a thicker front swaybar from a '70's Firebird/Trans-Am will bolt on to the front of your car, and aftermarket suppliers can set you up with a 1.5" rear bar (which seems to be the hot setup for neutral handling). The springs from a late-80's police Caprice seem to be the preferred setup as well. I'm going to be doing this next on my car, so I can't say for sure what's best here. The rear sway bar from a '73-'77 A-body will bolt on to the stock locations.
I'm beginning to suspect that the factory engineering on the '77-'85 B/C bodies borrowed HEAVILY from the '73-'77 A-bodies, such that many suspension (and exhaust?) pieces are interchangeable. That would be nice, if the rear ends would swap, as the strong 8.5" rears are much more common in the mid-70's A-bodies than in the later B/C bodies. THIS IS ONLY A SUSPICION, HOWEVER! DO NO BUY SOMETHING TO SWAP ONTO YOUR CAR BASED ON THIS SUSPICION, AS THERE MAY BE NO TRUTH TO IT WHATSOEVER!!!
Check out the http://www.b-body.net technical section. Almost everything that they talk about in the suspension mods will work. For example: 2nd generatation F-body front sway bars. They are 2mm thicker than the stock b-body bar. They recommend a Herb Adams rear bar.
There's another Impala site that has a lot of good stuff, too, at http://w3.one.net/~rcheek/impala/home.html
Also you could install a 3rd gen f-body steering gear box, one from a z28 or ws6 trans-am will bolt in. There are upgraded upper and lower A-arms available from GM that have bigger ball joints. If you are setting up a b-body to handle well you should really consider these. Also a simple and cheap handling upgrade is the Buick frame brace. It's about $15US. There are upgraded lower rear control arms available from GM also. GM started using upgraded lower control arms in mid-late 96 on the B-bodies. They are stronger than any previous ones. You can buy them for about $40 US.
Just swapping out control arms for new ones is a good idea. Less downtime, less aggravation, guaranteed success. And for the money it can't be beat. Same goes for the front a-arms with the HD Limo package ball joints. They are ALOT more $$$ though.
The Buick harmonics brace is probably a solid steel square tube, kind of like a sway bar. I also like the idea that it might just protect the fuel tank somewhat in a crash, too.
I'd find a rear end from an 89+ 9C1 first. That way you get the 8.5 inch rear. Also if you can find a complete setup from a 94-94 9C1 or Impala SS you can use the disc brake setup too! Or you can just buy the parts and bolt them onto any 8.5 inch 10-bolt rear. I didn't think a wagon rear end would work. I've been told they are up to 4 inches wider or narrower, not sure which it was now though.
I've had a couple of really interesting e-mails regarding adapting Impala/Roadmaster exhausts. One used only one side of the system, not a dual setup, the other used both the left and the right sides of the Roadmaster, requiring only a new front pipe at the driver's side. That strikes me as an easy mod and very cost effective, too. I've read about all kinds of problems with the transmission crossmember though. You might end up having to fab something for that. Sounds like you're up to the task though.
[ Thanks to Cecil Smalley, Bob Barry for this information. ]
1978 - 1988 G-body:
I have been told that suspension parts are interchangeable from F-bodies (Camaro's and Firebirds) made from 1970 1/2 to 1981 to A/G bodies (Monte Carlo, Grand Prix, etc) from 1977 - 1987, as well as the 70's X bodies (Nova, Appolo, etc). I know brakes from a late 70's monte will fit an '81 TA, and so will the strut brace (connects the top of the strut towers, much handling improvement, but might interfere w/ some air cleaners) I had a friend who claimed he put a Z28 sway bar on his 82 Monte - but I didn't ever look at it to see how it fit.
You might want to check out the Monte web site as a whole. http://www.access.digex.net/~miked/monte.html.
Yes, check out the write up that Steve Orlin did for g-body suspension and steering. He notes spring rates and what will work for your car, depending on what kind of driving you do and what kind of handling you want. http://www.access.digex.net/~miked/howto.susp-steer.html.
Steve Bantz also did a suspension mod write up which has part numbers, and instructions. http://www.access.digex.net/~miked/howto.suspension.html.
I recommend Moog coil springs #5610 front, #5375 rear and Gabriel "black" gas shocks.
[ Thanks to George Dumpit for this information. ]JJP442@aol.com
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