When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I went to tire rack to see what the diameters were for the OE Tires that come on the Turbo S. Three manufactures were listed and all had the same wheel diameters:
F:235/35X19 = 25.50" and R: 305/30X19 = 26.3" with a difference between them of :3.13%
I then looked at the GT2RS with Pilot Cup Sport wheels:
F:245/35X19 = 25.80" and R: 325/30X19 = 26.7" with a difference between them of :3.48%
So the OEM stock tires that come with the car are already slightly over the 3% at the most you stated, if I am doing the math correctly.
If 3.13% is where Porsche starts with on their OEM tires is 3.48 % in an acceptable region?
This is no doubt a question that should be posed directly to Porsche. I fired off an email to them. Hopefully they will respond.
Walt
The 3% guideline is for AWD cars - GT2 is RWD so no front differential to worry about.
I am stating the front vs rear diameter percentage difference. Currently I am at 3.18% with my 305's and 235's. I want to go to 325's and 245's. That difference between the front and rear is 3.48%.
The question: Is that an acceptable difference between the front and rear tire diameters on my AWD Turbo S car.
I mention GT2RS because I purchased GT2RS sized wheels and would like to run them on my Turbo S. To get tire diameter numbers on Tirerack you need to look under GT2RS since 325/245s will not show up under 997 Turbo/S.
Is -2.5 camber considered aggressive or just little more than is stock?
What kind of tire wear could I expect with -2.5?
Thanks, Walt
Semi aggressive and what you will need around that to run most all R-Comp tires...like MPSC, Pirelli Trofeo and so forth.
I run -2.6 front and -2.2 rear for track and street. Street tires are wearing ok...front wearing a little more on the inside...but thats is the price to have it handle great on the track.
agree with this. I'm running 19x8.5 ET45 up front and the wheels are perfectly flush with the fender. I think 19x9 ET47 would be another 4-5mm beyond the edge of the fender. Don't know if this would cause drivability issues but it might look odd without the aggressive camber mentioned above
A 19x9 will be .5" or 12.7mm wider overall, or 6.35mm wider on each side. et47 is 2mm less aggressive which means it will be 4.35mm further out and 8.35mm closer to the strut.
I have the GT2RS wheels on my 997 GTS which is the same offset/rear dimensions as the 997 Turbo. No issues with fitment, and rear wheels properly fill out fenders.
Sorry for the late reply. I just noticed this thread was active again.
No problem running these for me.
Fronts
"9JX19 H2 ET47" 245/35 19"
Rears
"12JX19 H2 ET48" 325/30 19"
I did get a little rubbing on the right inside rear plastic fender liner from my Trofeo R Comp tires. They rubbed a small area about 2x2 inches. I just cut a small hole in the fender liner there so no more rubbing.
I tracked the car multiple times and never received any overheating trans issues or warnings.
03-03-2013, 07:21 PM
