Is it safe to drop from 19" to 18" wheels & tires on a 997.1 TT for track purposes without having to worry about harming differentials and whatnot? What sizes front and rear keep it within spec? Thanks,

Edit: After thinking more about this, it probably would also negatively impact the computer (speed readout, mileage calculations, range to empty, etc.) and the PSM and ABS systems. Probably not such a great idea after all........

 

18's are fine with the proper tire size. Keep in mind most 18" wheels fit over the steel brakes but only a handful fit over the PCCB's. Eclou runs 245/35/18 front and 315/30/18 rear Hoosiers.see post 24

 

R888's and Sport Cups (of course) are available in sizes that will work with the 997. You do not want the ratio from front to rear not to exceed 2.5%, rear always larger.

 

My 18in Zehns dont fit over my PCCBs, ceramic brakes are too big.

 

It will look lik a matchbox car so make sure you put them on and take them off in the pits

 

For the track the 997.1 does quite well with 19's and I am willing to bet that most reputable shops have great set-ups for 19's as I am willing to bet that is the most common size for the track.

 

I have HRE r40 in stock have a lot of race guys running them perfect fitment no problems! if you want a deal i got them ready to go .

 

HRE R40 Series or C90 Series are both good options for 18" fitments

 

You can safely run 18" over steel brakes, and easily really! You need to keep an overall rolling diameter (wheel + tire) similar to the 19" stock wheels.

There is absolutely no issue with running an 18" setup on a 997 Turbo, zip, zero, nada, as along as it respects the above criteria.

If you have PCCB, very few wheels will clear. Custom 1 piece or 3 piece forged wheels can be made to fit. If you are on a budget, the Forgestar CF5 can clear 380mm rotors - one of the few 18" wheel that will.

 

Does anyone know if the 996TT stock hollows fit over the pccbs?

Edwin