Suspension upgrade questions

[Clone TIE Pilot]

Both poly bushings and boxed/tubular control arms cause binding and induce more stress into the control arm mounts that can twist or shear them. The rear suspensions on these cars were designed to have lots of flexing as part of normal operation to avoid binding and snap oversteer. The only aftermarket arms that do not have binding problems are arms with poly ball joints. http://scandc.com/new/node/646 Most aftermarket suspension parts for these cars are intended for drag strips where you mostly just go straight, most are not designed for high speed turns like normal street and highway driving. About the best upgrade is to replace the lame stock rear sway bar with a aftermarket axle mounted rear sway bar which reduces binding. http://scandc.com/new/node/684

 

[UNGN]

As noted, a larger than stock, stock location swaybar will greatly reduce understeer, but will crush stock control arms like a puny bug.

The binding and snap oversteer will happen if you take the autocross handling out into the real world, generally at speeds much higher than are legal. If you only pull G's in a parking lot or on smooth off ramps, a monster stock location rear sway bar with aftermarket lower control arms will be fine. Just don't hit a pothole at the apex of a high speed corner.

 

[gbodytoys]

I started with UMI's stage 1 kit....springs, shocks, new front/rear sway bars, 1" drop. I'm not going to to say it made a huge difference...yet, but that "boat" "float" feeling is certainly gone. On my first burn out, I noticed "wheel hop" for the first time, or at least what I think is wheel hop. It's much tighter to the road, without being too rough.

The most annoying thing is that now I can hear all of the rattles from everything else wrong with the car lol. When everything on the car is wrong, you just get used to it, when you start fixing stuff...the wrong stuff seems 100x worse. Suspension wise, I'll address the rear control arms next.

 

[pontiacgp]

as far as binding the uppers will bind if boxed without a spherical end on one side. Here is a picture of the elongated hole on an upper that was boxed for testing purposes.. The suspension will bind but it will not snap unless something breaks. The reason we tested boxing the upper is to see if we could use the binding to our advantage. 4 link suspensions turn the back wheels in the wrong direction in a turn whch we were trying to limit. We had to use stock control arms in the rear in the division we were in. G bodies are ok on a 1/4 circle track and a 1/3 of a mile track but don't work on a 1/2 mile track with stock links.

 

[Clone TIE Pilot]

If GM designers weren't concerned about binding during normal driving, then they would have not made the rear suspension as compliant as they did. The stock arms and bushings are flexible by design to keep the cars safe to drive. You can't get rid of the twisting, you can only change what twists and you don't want the weak lca mounts to twist.

 

[tommytpk]

I'm probably going to start with a 7/8 "stock" rear sway bar and keep the stock control arms, unless the bushings are completely toast. I don't want to compromise my saftety, but I would like the vehicle to ride and handle a little better.

 

[pontiacgp]

I don't like the bars that mount on the lower control arm. I have an F body GTA rear sway bar that I used the stock mounting hardware. The F body bar just needs to have the ends bent in an inch or 2 so it doesn't hit the lower control arms

 

[Clone TIE Pilot]

A simple upgrade would be to replace the rubber bushings with firmer 1LE rubber bushings, which all replacement rubber bushings are now. Even new stock bushings will give a better ride over wornout bushings. Aftermarket arms with poly ball joints are safe, just the short gap aftermarket arms with plain poly bushings should be avoided.

 

[Algershick]

Pontiacgp, why don't you like the bars that mount to the LCA?

 

[pontiacgp]

Pontiacgp, why don't you like the bars that mount to the LCA?

I don't like how it is designed and assembled. With the arm bolted in two places on each side it doesn't allow the sway bar to naturally twist. It was GM's cheap way to add a sway bar and stiffen up the lower control arm. It does work but I'd rather have the bar attach to the frame and not the suspension