What are the specific functions of a PT style rear sway bar on a 64-67 A body?

[Nicks67GTO]

Hey guys.

I'm wondering what the specific functions are of a rear sway bar? specifically on a 64-67 A body. Iv'e got a 67' GTO for reference.

Does it help keep the rear end centered around hard corners? Help control rear body roll? Help eliminate wheel hop? can someone pin point what exactly a rear sway bar is intended for? Since i have no rear sway bar currently and only have stock boxed RCA's and rubber bushings with bilstien shocks, would i see a drastic improvement in handling if I went with the Helwig adjustable bar in the link below?

BTW here's the one i'm looking at very strongly to compliment my 1.25" WS6 bar i have in front.

http://scandc.com/new/node/266

[chevelletiger]

[QUOTE=Novaguy73;929211]Hey guys.

I'm wondering what the specific functions are of a rear sway bar? specifically on a 64-67 A body. Iv'e got a 67' GTO for reference.

Does it help keep the rear end centered around hard corners? Help control rear body roll? Help eliminate wheel hop? can someone pin point what exactly a rear sway bar is intended for? Since i have no rear sway bar currently and only have stock boxed RCA's and rubber bushings with bilstien shocks, would i see a drastic improvement in handling if I went with the Helwig adjustable bar in the link below?

BTW here's the one i'm looking at very strongly to compliment my 1.25" WS6 bar i have in front.

http://scandc.com/new/node/266[/QU
great rear bar with three adjustments softest at the very end of the bar stiffer on third hole.with the hour glass shaped end links mounted to the rear crossmember theres no bind like with the control mounted bars,and its light too at 17lbs! this bar compliments a 1.25 bar.i was going to get a 1 5/16 bar and mark said it was too much bar with this 1.125 rear bar,and yes this bar helps body roll.talk with mark he'll set you up!

[Rod]

the bar will not keep the rear end centered
It will reduce body roll,
It will reduce wheel hop
It will also increase traction in corners(and a little off the line) by making the car stay level(more level) in the corners and on take off

[Vegas69]

Simply: It adds spring rate which will loosen the car up. Reduce understeer. It could give you to much oversteer depending on your current spring rate, front spring rate, and front sway bar.

[sanman357]

Sorry noob time. So you could over sway bar a vehicle?

[SLO_Z28]

Sorry noob time. So you could over sway bar a vehicle?

Yes. Spring rates, sway bars, and shocks all need to work together in unison to get the tires to act correctly for any given application. Specific problems that are common from over barring a rear suspension are roll steer which will cause push, and unloading the inside rear tire which will make it difficult (or impossible) to get the traction necessary to accelerate on corner exit.

[exwestracer]

the bar will not keep the rear end centered
It will reduce body roll,
It will reduce wheel hop
It will also increase traction in corners(and a little off the line) by making the car stay level(more level) in the corners and on take off

Sorry to disagree, Rod; but the bar does not increase traction on the end where it is installed. It actually does exactly the opposite.
Look at it this way: If a car understeers, that means the front is losing traction first. We could say that the rear has "too much" relative traction. By adding a rear bar, we get the car to rotate better or "loosen up". Remember, we haven't made any changes to the front, so the only way this can happen is if we are taking away some of the "excess" traction we had at the rear. That's really how it works...

A rear bar will "increase" (balance, actually) drive traction on a straight line launch by counter-acting the natural chassis roll from engine torque. In most cases, a "drag bar" setup on the rear is WAY too much sway bar for proper handling...unless the car has a bad understeer problem to begin with.

Usually, if you get the front right on an A body (camber curve, scrub, etc) you don't need much rear bar, if any. If you find you're having more fun in the corners with a giant rear bar, there's probably some front traction left on the table somewhere.