Track Wheels, 16, 17 or 18"?

[mgfranz]

For autocross events, has anyone played with different rim sizes? I run 18" on the street, but was curious on others opinions. For autocross events, is there any big differnce between a 16,17 or 18" rim assuming the same diameter tire? I know that lower profile on a 18" would be tighter, but then the 16" with a 55 might give better roll. Thoughts?

[BrantyB]

Rim size will govern a bit of what width wheel/tires you're trying to use. I think people use 17s to go with a square setup of 255s but that may also require swaybar changes to keep understeer in check. A square setup has the ability to rotate all 4 evenly. Also, not all tires are available in all rim size and width combinations.

I looked into this over the winter to possibly make some changes. I decided to stay with 18s because it is the best compromise for me with the car's setup and classification.

[JayG]

17's are the way to go.

Lots of tire choices and you will save $$$ over 18's

Also for early year cars it not recommended to use 18's

Square setup is what some people use, but the vast majority are staggered
In 17's 255/40-17 rear and 225/45-17 front is a good setup for both AX and track

[Topless]

Originally Posted by mgfranz

For autocross events, has anyone played with different rim sizes? I run 18" on the street, but was curious on others opinions. For autocross events, is there any big differnce between a 16,17 or 18" rim assuming the same diameter tire? I know that lower profile on a 18" would be tighter, but then the 16" with a 55 might give better roll. Thoughts?

Most run 17s for AX/DE/TT because the tire size/width is just right for the 986 car balance and there are a ton of good tire choices available. I run 18s on my 987.2 and they do allow a bit wider tire but they cost 30% more. If I were running a 986 again it would be on 17s for certain.

[mgfranz]

I like the idea of using a balanced setup, it would possibly save a few to be able to rotate... 18" is probably out, rims are expensive in that size and what would I actually gain? 5mm? Besides, a smaller rotation on the rim with that same size profile tire would be a faster RPM on the tire anyway right?