Question: I have seen older muscle cars with traction bars on the rear leaf springs to prevent the car from squatting when stomping on the gas. When I stomp on the gas in my 84, the rear end does not move downward at all. Is this normal, or do I just have really tough springs?

 

The traction bars actually prevent the axle from twisting the leaf springs on those older cars into an "S" shape when all that torque suddenly goes through the rear.

Your 84 has a different type of suspension, so it's comparing apples to oranges (at least assuming your car has the stock coil spring setup).

 

he's right. You have coil springs instead of leaves. My 84 squats a lot when i punch it, I like it even though it wastes energy. Maybe I have worn out shocks or am making more power.

Are your springs stock?

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84 Z28 L69. 5 speed with 3.73 posi (broken)Ported heads, intake, 10:1 comp. 230/230 .480 lift cam @.050" w/108 LSA

Triumph Spitfire SCCA roadracer. 1.1 liter 4cyl w/ 14:1 comp.
turns on rails!

 

While tracion bars do reduce or stop leafspring wrap, they also do more.
The traction bar uses the twisting force of the axle to push up on the body of the car where the snubber contacts it. While doing this it is pushing down on the rear axle to help plant the rear tires for better traction.
Think of standing sideways in a doorway with your back against one side of the doorway and your hands against the opposite side at shoulder level. Using your arms, push your back against the doorway.
Think of your body pushing against the doorway being like pushing the body of your car against gravity. Think of your hands as rear tires. Think of your arms as the rear suspension of the car. While your arms(suspension) are pushing your back(car body) against the wall, they are also pushing your hands(tires) against the other wall. Now move your hands up along the doorway as high as you can while still keeping your back on the opposite wall. Now push. You can't get as much force against your hands(tires) so you don't have as much traction.
This is how traction bars improve the grip of the rear tires, pushing up on the body of the car close to the rear axle.


Your F body suspension uses a torque arm in a simular fashion to push up on the body of the car. It is longer than traction bars though and so it pushes up a little further forward on the chassis. This helps transfer weight from the front of the car to the rear tires on launch, but doesn't push directly down on the back tires as much. Many aftermarket companies manufacture shorter torque arms to move this upward pushing force back some to push down on the tires a little better by reducing squat even more.
your car probably squats more in the rear than you realize, but they don't squat as much as older designs did.

Ladder bars are very simular in their function as the torque arm.

The control arms that attach your rear axle to the chassis also convert the twisting force of the axle into upward thrust on the body. The relative positions of the front and rear pivot points of the control arms determine where on the car that this upward force is applied.
If you lower the car you move the front mounting position of the control arm down in relation to the rear mounting point. This moves the "upward push" too far forward and will cause excessive squat, loss of traction, and tire hop.
You fix that with control arm relocation brackets.
you can also use them on none lowered cars as well to reduce squat and to adjust where the "upward push" occurs on the chassis.

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Tracy /AKA IROCKZ4me
'86 IROC-Z Camaro
"Cogito ergo zoom"

• 355 cid
• AFR heads
• Arizona Speed & Marine hydraulic roller cam w/ AFR hydra-rev kit
• modified SLP runners
• TRW forged pistons/ceramic coated
• fully balanced
• Edelbrock headers/ceramic coated
• SLP cat-back
• Paxton supercharger
• Nitrous Express nitrous oxide

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[This message has been edited by IROCKZ4me (edited December 05, 2001).]

 

As far as I know, it is all stock. The springs are as dirty as the rest of the underside! I wouldn't put traction bars on my car, anyway. I have seen them get peeled off of a car by road debris and speed bumps.