I have an 87 IROC and I was low on cash but needed rear tires really badly so I found these two Kumho Ecsta STX tires 255/55/16 to throw on there until I could afford to get a new set. Turns out they are really good tires and they still have a lot of tread left.

At the time I purchased the car, the PO had stripped some of the parts off but left the original worn out Bilsteins on the car and fragments of the sway bar bushings were left.

I have replaced the sway bar bushings and end links with aftermarket (poly) stuff, I installed a beefier rear sway bar and also had the lower control arms beefed up a little. The welder was supposed to box them with steel but instead used round tubing and arc welded down the center of each arm. I also found a complete set of KYB GR2 struts and KYB Gas-a-just rear shocks on a car in the junkyard and thats what is on the car now.

When I take a curve too fast or accelerate sometimes the body will roll enough to the left that the rear fender lips rub the tire and you can hear it from the cabin. The passenger side tire doesnt really have much damage, hardly any, but the drivers side has a lot of cuts in a raised part of the sidewall that used to have instructions on it.

Is this normal or do I need to be looking for a suspension culprit?

I am on the fence about rolling the fenders right now. I was just going to wear them out and put the stock size back on but they arent wearing that fast.

 

for me it is the passenger side, you should check to see if the rearend is centered i know mines not but im not much of a corner guy.

 

Stock wheels? What size?

Could be the rear axle is offset, as already mentioned. Could be aftermarket wheels setting out further? Stock height or lowered? Could be a combination.

 

Its got stock 16x8 IROC wheels.

The car is stock. It looks like the original owner crashed it in the front passenger side and stored it for a long time. When I bought the car, it had original Goodyear Gatorbacks on it.

The radiator support was bent back into quasi shape and they bolted on replacement parts. The rear end looked untouched when I got it.

When I do take off, however, the rear has a tendency to swing out to the left, which is weird to me.

Here is a photo of after I got it and replaced the dented, pinned hood:

 

I would start by checking out the PHB. Good bushings? Bent? Axle just offset like they usually are? (use a string & weights to measure) I got an Adjustable Panhard Bar to center mine.

 

front (zero offset) wheels on the rear maybe? Stock rears are something like 17mm pos. offset.

 

Drivers side:


Passenger side:


I aired them up to 35PSI and going to run them like that for awhile to see how they feel. An adjustable panhard rod maybe just what I need, I think it may lean way too much even with the larger sway bar.

LCA's:

 

Have you used a string & a weight, to measure if the rear is centered or not?

When does it rub....Hard corners? Deep road dips?

 

Haven't gotten a chance to jack it up yet and probably wont until I get GF's sister's Cadillac out of the way (starter locked up).

It rubs when I do a hard turn to the left and sometimes when I accelerate in a non-linear fashion the rear torques and it rubs.

I don't remember the stock size ever rubbing and this only started when going to the larger tire.

Hmm, maybe I should also check the torque arm...

 

Rubs when turning left....So it rubs on the Passenger side? Typically the the rear axle gets shifted towards the drivers side, if the PHB is an issue.

Do the string I keep mentioning. It'll tell us where the axle is.

 

The side that it rubs the most is the rear drivers side.

 

How does it rub on the drivers side, turning left, when the body should be moving up away from the tire? Rubbing on the inside or outside sidewall?

 

It cuts into the outside of the sidewall where the fender lip is, that's why I was thinking of rolling the fender.

 

Please....Do the string measure. It'll tell us SO much!

 

what is cast into your rear wheels on the spokes?