wtb-z

I switched from tracking a C5 Z06 to a C6 GS a couple years ago. With the C5 Z06, I usually ran 4 rear wheels, and I think that was a pretty important setup choice. With the square setup the car was a bit too loose on turn-in, but steady state balance was good and tire wear was pretty balanced. With the stock size tires the fronts would always die way before the rears, which felt pointless.

The first thing I expected to do on the C6 GS was to do something similar in terns of getting more front tire on the car. But I started out with a set of extra C6 Z06 wheels and stockish size 200tw tires. Despite being a heavier car and with the huge stock stagger of the C6 widebody, the car does not feel nearly as front limited as my C5, which makes no sense. Turn in is mild, mid corner balance is shockingly free, the car already drives like it should. Or at least as well as could be expected from something with stock soft springs, bushings, etc. The outer edge of the front tires are not really happy, but overall front to rear wear feels balanced. Generally the car feels like it is using both axles about equally.

Do people put more front bar / front spring on these cars when they do big wheels and tires? Or do setups manage to find even more rear tire to go along with the front? Or should I just keep buying 275F/325R sets of tires for it?

Nowanker

11/13x18 is pretty common, 315/335 or 345, depending on availabliity
Mine already had LG coilovers & aftermarket bars on it when I bought it, but it'd be standard to up the F spring rates and/or sway bar to balance the car.

jw1

I think a lot of people build their cars around the ruleset they are competing in. If you are not limited by a ruleset then high rate coilovers and Hoosier A7s are what you want.

Bill Dearborn

315/30/18 Hoosiers on 18x11 work well in front while the 345/35/18 Hoosiers mounted on 18x13 wheels in the rear complement them very well. The 18x13 wheel will contact the rear of the UCA when the suspension is at full droop so you can't tighten lug nuts until you depress the suspension some.

Bill

slow04cobra

There is a guy in socal whom is trying out running 335's in front. Have not heard how they work out yet. Since Nasa ST2 takes a hit for the wider tires he was thinking why not try them in front.

PRE-Z06

I started out stock C6GS after coming from modified C5FRC. First I did was go to stiffer front sway bar as the grand sport is more softly sprung, burned up the PS2s that came with it along with 275/325 SC3s. Tried 285/305 RE71R on stock rims. Then tried 305 square which I didn’t care for as it was as you described, so went 305/325 in SC3s on 19x11/12 rims. Have since gone coilovers and delrin bushings and switched to 18s, which have been 285/315 Nankangs on 10.5/12 and 315/335 Rivals on 11/12.5 and like them best. Tried 315 square again with 660s and it was tolerable as I staggered height with 18x12 and 19x12 rims, but don’t like the 12s up fronts as they rub.

wtb-z

He's on this forum, but I think he needed to put more front bar on the car.

I guess that's a change to consider as well. This is a mag ride GS, and similar to what a couple other people on the forum have reported, it seems to have come with the FE5 sway bars on it. But there are some 35mm front sway bars out there that maybe could balance out more front tire.

AtomicZ

Bill - I run 18x13 CCWs on my '07 Z06 - no issues with the UCA. - Eric

'12GS

It seems like the standard setup is 315/345 on 18x11/13. You can fit 12s on the front if you don't care about a little bit of rubbing. I've run square setups and some staggered setups and they've all worked for me, but I did install a giant front sway bar to make sure the car doesn't over-rotate with a square setup. I've run 18x12/13 with 335/345 hoosiers a couple times before and I really liked that setup, personally.