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?
Bushings:
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.
Control Arms:
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.
Roll Cage:
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
Stabilizer Bars:
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.
Sources:
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. ]
Aftermarket
This is not an all inclusive list of aftermarket suppliers, just examples
of what has been discussed on the Olds Mail List.
Comments:
Herb Adams:
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 ]
Alignment
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.
[ Thanks to Mike Rothe for this information. ]
Ball Joints
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. ]
Bushings
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.
|
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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.
|
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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).
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Del-A-Lum bushings Pro's - Probably the best performance bushing you can
buy and use.
|
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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) | |
Size reference:
| 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) | |
Size reference:
| 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. ]
Hotchsis A-Arms
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:
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 (just ask Jason Adcock). 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!)
Polygraphite:
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!).
Polyurethene:
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.
Tip:
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 (El Cam*no): $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, Chris Witt,\
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) | |
Size reference:
| 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.
Size reference:
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) | |
Traction concerns:
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.
Aftermarket:
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. ]
Shocks
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, Greg Rollin, 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. ]
Springs
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. ]
Warnings & Safety