Palting

Been researching all weekend. Viscous coupling, PSM and ABS mandate a less than 2% (I think) difference in rolling diameter between the front and rear tires. MPSC's finally have the stock sizes for the C4S, 225/40/18 fr and 295/30/18 rr, same as the turbo. I thought I'd put a little more rubber on the road.

Anyone try 235/40/18 fr and 315/30/18 rr? C4S/turbo wheels with 8" and 11" width should handle those sizes. Think there will be any issues with rubbing, weight, what-not?

Thanks!

ebaker

I'm running the 235/315 combo on stock rims with no problems in street use.

Palting

Good to know. Thanks!

Woodster

How about 235/35 zr19 (front) and 315/25 zr19 (rear) for street ??
specs show 819 (front) and 825 (rear) revs per mile
for Conti Sport2's
I show factory Bridgestones (18's) at 823 and 837

Marty Kaye

03-turbo911

Marty, you could run 305/25/19's as this size is said to be as close to the original setup. Porsche is also running this size on the new c4s and turbo.

tkerrmd

I run 19's with 245/40 and 315/25 and also have rear GT2 wheels with 12 inch width and 315. Both ok for the street. Dont recommend 19's for the track.

Woodster

Thanks guys!

Marty

damianc4s

MPSC are generally wider than other tyres for the same width setting. 235's will rub on the front when you are on full lock.