Viken

Here are the figures with factory equipment:

Front track:
996 with 18" wheels/tires: 57.70 in
GT3 with 18" wheels/tires: 58.50 in
GT3 Cup with 18" wheels/tires: 59.70 in
GT3 RS with 18" wheels/tires: 61.50 in
997 with 18" wheels/tires: 58.50 in
997 with 19" wheels/tires: 58.50 in *

Rear track:
996 with 18" wheels/tires: 58.30 in
GT3 with 18" wheels/tires: 58.90 in
GT3 Cup with 18" wheels/tires: 62.20 in
GT3 RS with 18" wheels/tires: 62.20 in
997 with 18" wheels/tires: 60.40 in
997 with 19" wheels/tires: 59.70 in *

* 997 Carrera S comes standard with 19" wheels and tires

cosmos

What makes the GT3 Cup and RS trackes wider? Do they have different size wheels with different offsets?

macfly

Thanks Viken, great info.
Is the RS track wider due to both control arms and offset, or just one or the other?

Bob Rouleau

Hmm how much wider if the Cayenne V8 than the flat six?

Viken

Yes.

Viken

Andrew, the GT3 RS listed above is the race car and not the street version. The street GT3 RS version is identical to the standard street GT3. I guess I should have called it the GT3 RSR since that's what it's called nowadays.

Bill - Chicago

Viken - is the GT3 cup quoted above an 04. If so do you know if the specs are different from an 03.

Thanks.

Viken

AFAIK, they are the same.

cosmos

Also what are the offsets and the wheel sizes of the cup car? Can we fit those sizes on the street car?

Viken

The Cup car comes with magnesium center locking wheels and racing slick. They won't fit without further modifications to the hubs. There are people on this forum who own both types of cars. I am sure they'll be able to explain this better.

Karl S

Actually the wheel centers are aluminum, magnesium centers are available from BBS but not from Porsche. Mag centers are illegal in the stock Cup classes in PCA but are often used in other series such as Grand Am. The wheels for the 2004 cars are:

front
GT3 street - 8.5J x 18, offset 40
GT3 Cup - 9J x 18, offset 46

rear
Gt3 street - 11J x 18, offset 63
GT3 Cup - 11J x 18, offset 59

As Viken noted, the wheels are set up for center locks but they can be drilled for use with studs, which is required in Grand Am (center locks are illegal in the SGS class for some reason). The Cup cars are actually delivered from the factory with rain tires only. You can then buy whatever type of track tire you want, slick, DOT R, etc.

cosmos

If I was to order wheels from Fiske, or HRE, what size and off set would I go with? Can I go with Cup car sizes front and rear as well as offsets or will I have problems with clearence? Also what size tires doI run?

Viken

In another thread you mentioned that all you're going to do is some DE's. For that, I would stick with stock sizes. In fact, the stock tires are great for track driving.

cosmos

I guess it is years of M3 driving that has me in the mind-set that wider fronts is better. I really like that 9" front option of the Cup car, with the 11" rear.

Karl S

I had a set of Fikse FM-10 track wheels for my 996. The fronts were 9" and I was able to run a 245/35/18 tire with no rubbing. A competent Fikse dealer should be able to set you up with a 9" wheel with the proper offset to fit the GT3 if you really want them.

Karl