Any GT2's running the following tire combinations?

245/35/18
315/30/18

Notice there was a lot more front tire options at with aspect ratio of 35. Does anyone know if there will any adverse affects running 35 instead of 40 from factory spec? I am wanting more front grip but not sure the effects of changing the tire aspect ratio. Thanks in advance

 

That's a popular size that guys run on 6GT3s on Hoosiers. With that said, the fronts are very short at 24.8" with the rears at 25.5". Some guys run these on 7GT3s. It's a good set up on GT3s which are lighter and benefit from shorter gearing. I don't care for that combo much as the diameters are very shorts and further shorten the gearing on the turbo cars which benefit from taller gearing. I like the larger tires which offer more grip and performance due to the taller sidewall. Unfortunately there is not much choice in tires these days in 18s unless you wanna stick with the OEM sizes. For a street combo, I really like a lightweight 19x9x12 wheel set up shod with the new Michelin Pilot Sport Cup IIs in a 235/35/19 and 305/30/19.

 

Yes GT3s have too long gearing stock for track, and we all know that GT3 vs. Turbos have different gearing. But please provide more info how Turbo/GT2 benefits from taller gearing than stock? I understand preferring the larger tires due to more sidewall and more contact patch, that I agree 100%, but am not entirely buying the taller gearing part. That's new to me. Might be that on a certain track you save surprisingly many shifts and that's why taller could be better?

I believe I can get some gearing data from some Swedish track GT2 friends who have tried all sorts of gearing...but at the moment I'm just guessing that taller gearing doesn't make you faster.

 

We don't have the luxury of a high redline. We have torque..... My car is definitely faster with taller gearing.. Most people will agree that 1-2 is pretty much useless in our cars. 1-3 is taller in the 997TT/GT2 cars. Our cars were geared for 420hp and not 550+ what most guys are running. If you have the torque to run the gearing the allows you to skip a few shifts than that is time in the bank. I'm sure there are some track where shorter gearing would be better but all around I feel that slightly taller gears work better (for me anyway). Your results will vary. The biggest problem with the short 18" tires is the lower load rating they carry compared to the taller ones. Again, just my opinion.

 

Thank you for sharing your opinions. I am new to this and still learning.

 

265/35-18 front and 315/30-18 should be perfectly matched. But you need a 9" front rim