Will you use 325 tires (cup) or stay with OEM 305 ????

 

can you say major grip

 

Doesnt really matter. 325 will just give a bit more grip. Even though the cups have a boatload already.

 

OK several things come into play as I've encountered with my GT3.
If you lower the suspension and corner balance the car as I did along with aggressive track suspension/alignment settings you will rub the fender.
Keeping the 19x12" rear rim and the stock offsets you can not run a 325 tire. Only unless you roll the fenders.
I am running the Pirelli Corsa's and maybe a credit card may slide by. The look is awesome. Will post pics when the project is over.
The new tire dimension of 325/30/19 is now available so will probably go ahead and roll the fender. That 325 should look very stout in the fender well.

Cheers, GT3Ranger

 

But the GT3 already has rolled fenders.

I don't understand why you can't put 325s...I mean the offset is the same, the width is the same. With 305s as it is now, the tires look like it's stretched out to the edge of the rims. With the 325s, it should bead more square with the rim. 305s should be on 11" anyways. 325s will be perfect for 12" width

 

Staying with the 305 as the 325 might lead to more understeer.

 

325 can affect acceleration ?

 

Hey P97 how goes it? The guy at Champion told me that and I felt in the fender and there is an edge sticking in. I'm not absolutely sure though.

luiscarlos the wider tire could have an effect on straight line speed. What the other member said about inducing understeer, well I can see that potentially.

The new GT2 comes with 325/30/19's, I guess Porsche has it figured out.

When the current tires wear out, I'll try it.

Cheers, GT3Ranger...Juan

 

Will running a taller rear tire cause any errors with traction control or PSM? What about balancing it out with a 265/30-19 in the front (if that will fit)?

 

265/30 is actually a tiny bit shorter tire than the stock 235/35 so it will actualy "unbalance" it more

the last thing the 997gt3 needs is more rear tire

the gt2 with the huge torque was given the larger rears to make sure it doesn't develop the 996gt2 reputation - lets face it, for 99.9% of the guys that drive the new 997gt2, the car will forever be way beyond their limits and giving it a little extra rear grip is a very smart thing - the gt3 on the otherhand will really only step out on slower speed corners if you have large steering input and you heavily apply the throttle - the gt2 with TC OFF is likely a scary car to drive anywhere near the limit -the gt3 is not

i'm working on the 265 but running close to -3 camber is required

 

The stock 305/30/19 has a rolling diameter of 26.20"'s and the 325/30/19 is 26.68"'s therefore 0.48 or 0.5" taller. I do not know if it has any effect on any of the carsset parameters or gearing.
The 265/30/19 front is what Cargraghic is running on their car with the wider front fenders. As in the project that's going on with the thread from Mike at RSS.
Personally I feel it should have no ill-effect. If were an inch or greater that's different.
I just got new Pirelli's so it will be 3 to 4K miles before I try it.

GT3Ranger...Juan

 

Hey Juan,

Run your fingers in the fenders between 10 and 2 o'clock. You can feel the rolled fender. The edge you felt probably is between 9 and 3 o'clock where they did not roll them.

 

Don't you think the porsche factory put the size tire on it that best works?????