15" wheels improve track performance?

[fatjohnny]

I was at the track this weekend. One of the drivers mentioned that putting lower profile tires on my 16" rims (for an 87 911) could improve acceleration and that 15" rims could improve it even more. Make the car more nimble etc. Mentioned it would mess with the speedo and odometer, but since it is just a track car it would not be a big deal.

Any thoughts or wheel/tire recommendations?

Thanks!

[RaceProEngineer]

Johnny,

There have been volumes written on this subject right on this forum. Try searching for "wheel diameter". Here is one I started some time back, in response to many (MANY!) questions just like yours.

Down where the Tire meets the Track !

Essentially, the smaller vs. larger diameter wheel question represents a trade-off (like virtually every other performance enhancer.) All other things being equal, a smaller diameter wheel/tire combo yields more torque (acceleration); while the larger diameter combo allows more top speed. So, one might gain some advantage by running the smaller combo on the rear at a place Lime Rock, and the larger combo would be beneficial at Pocono.

Or, at your favorite track, does your Carrera "want" more acceleration, or more top speed? You can change your gearing without changing ratios in the box.

Ed

[fatjohnny]

Perfect! Thanks.