Ifitaintbroke

Hey guys, just recently I installed a set of staggered 255/40/18 front, 285/40/19 rear C6 Corvette rims on my z28. With these new wheels the car rides HORRIBLE, and I mean HORRIBLE where it pulls all over the road, is terribly rough over bumps, and the rear end is all over the place when I go over bumps taking turns. It just makes the car ride and handle horribly all around, and I mean its BAD, not just annoying, but makes me want to just run the stock wheels.

I also installed brand new Bilstein shocks, BMR lowering springs, and Founders panhard rod and lower control arms, non adjustables. With all the suspension stuff in and the stock 16" wheels on, the car rides AMAZING and handles great. Even with my buddies set of 17" Z06 rims, the car is perfectly fine, it ONLY DOES THIS with the 18/19 C6 rims and I have no idea why.

It's bizzare. I even tried running the 19" rears with my stock front wheels, and it wasn't nearly as bad but it was still there. Any idea what's causing this?

therabidweasel

iTrader: (5)

Have you played with you tire pressure? Other than a small change in caster perhaps I can't think of anything else. What are the tires, used them before?

Ifitaintbroke

Yes I've tried changing the PSI up and down, doesn't make a difference. Right now it's at about 28psi... the sidewalls on these tires are incredibly stiff.

The tires are super expensive Goodyear F1 Supercar tires, they run like $400 per tire, and they come on the rims when I bought them. They have a little less than 50% tread.

My front end is all solid, nothing bad, nothing worn, alignment is good, and almost everything on the whole suspension is upgraded, bushings and all - front and rear UMI sway bars & poly bushings/endlinks, poly/poly panhard, lca's, Bilsteins, BMR lowering springs, the works. Everything is nice and tight, and with the stock wheels on it not only rides pretty smooth but handles like it's on rails. These 18/19 wheels make it ride like a rickety unstable piece of **** -_-

Latch

iTrader: (8)

That's why I bought 17" wheels wrapped in comfy Nitto NT555s. 18s/19s with stiff sidewalls on the tires = covered wagon.

If you want to stay with the bigger wheels, which I'm guessing you do since you bought them, see if Nitto Invos come in the sizes you need. The Vette guys run the Invos quite a bit and they say they're a nice comfortable ride.

Just goes to show sometimes the big name tire with an equally big price tag isn't always the best choice.

ChrisRZ28

I run 17s on my car so I don't have any experience with anything bigger. But my Brother-In-Law has a 2nd gen 'pro touring' Camaro with 18s. You can feel everything on the road with those wheels and tires! I won't go any bigger then 17s on my car. Just doesn't seem to be worth it, IMO. My car rides quite a bit better then my BILs car does, and I've also have poly bushings in the UCAs and UMI LCAs with roto joints and it still rides damn good.