SteveC68

I downloaded the 2012 GCR and looked at the Touring Category which begins on page 679. Looks like not that many mods are available. It does list bore and stroke for each of the C6 engines (LS2, LS3, and LS7). Can you run a different crank, rods and pistons as long as the bore and stroke remain the same or are the stock parts mandatory? Also I have read on the forums that headers are legal, but I don't see that in the exhaust section which pretty much says you can remove the cats and replace everything after the cats as long as it's the same config as stock. And about wheels and tires. It lists a 18x10 front and a 19x11 rear for the max or an optional 18x11 front and a 19x13 rear with a weight penalty. Does that mean you have to run one of those wheel combinations or could you run 18" diameter in the rear? For tires again it lists a 315/35 front and rear or a max of a 315/35 front 345/35 rear with a weight penalty. So what tire and size is everyone using? The A6 or R6? As far as shocks go are you restricted to what comes with the T1 suspension kit or are other shocks allowed?

redtopz

I also was confused by the rules when I started setting my C5Z up for T1. They are inconsistent and continually updated. Basically in T1, you have to run a stock engine, clutch, and tranny. You can balance and blueprint the engine to factory tolerances if desired. I just run bone stock. You must also run the factory rear gear ratio but you can use a quaife torsen diff. Headers are only allowed on the C5 cars, but the LS3 can run a dry sump. You can run any shocks you want. You can run 295/315 or 315/315 tires front/back with no additional weight penalty. The C6 can run 345 rear tires with the grandsport fenders with a 50 lb penalty. You can run grandsport brakes or any 4 piston calipers as long as the rotors are within 5% of the stock diameter. You must use the specified wheel sizes. You can install poly or delrin bushings to the control arms. I think this is all correct, but I might be missing something. Hope this helps.

Most guys run A6 tires, but other tires include kumho 710, goodyear A or R compounds, hoosier R6, etc.

davidfarmer

T1 suspension bars and springs. The rules used to be that you could run UP TO the wheel sizes listed, so I would think 18's would be fine in the rear. We ran 17's when 18" were OEM (C5 days). Being forced to run 19" wheels would be very restricting