Dear folks,

Will the 245/35 and 325/30 fit the standard 997.1 GT3?
I have changed the Advan forged rims but the width is same as standard
8.5" F and 12" rear !

 

that would be a great combo is you like understeer.

I would do 245/305.. better balance

 

running a 325 in the rear wont cause understeer. it'll PREVENT oversteer.

 

While your statement is somewhat true, its the thought process that is flawed.

Your statement is contradictory.

1. YES, a wider rear tire will give the rear tires more grip and cause less oversteer.. but this grip does not magically appear. Car set up is give and take... so you are giving up front grip for more rear grip. (less front grip than rear = UNDERSTEER)

Porsche's are now set up to UNDERSTEER from the factory, this is accomplished with alignment specs and front to rear tire sizes. (they give our cars much less front tire to rear tire (why do you think the new GT3 Rs has a wider front end??)

Most street guys think more rear tire will make the car handle better... NO it will make the car understeer more, which is easier to control for the average driver and is safer, especially in a 911.

If you want a car to handle better (handle more neutral), then a wider front tire will balance the car much more and actually the car will handle better.

There is NO need for a NB 911 to have a wider rear tire than 305mm, unless you want a 911 that understeers very badly.

If this a street only car that never gets tracked or driving hard, then put the 325's on... but if it does.. try something narrower in the rear.

I know this because I have tried all these different set ups on my car and I now run a 250 front and a 280 rear on my car for the track and its the best combo I have found.

 

245 325 WILL understeer
255/315 kind of push too.
all depends on how comfy you are with the car and what you use it for.
but the OP asked if the tire will fit. they will.

 

mooty you're right i should have just answered his question without .02 cents.

YES, they will fit.

 

Thanks guys for the extra tips too. :-)

 

Yes they will fit BUT you can not do any suspension drop. For example my RS as is I can not run a 325 rear. Heck I doubt a 315 will fit.

Ranger

 

I have run 265/35/18 x 305/30/18 with great success. The car was very, very, very balanced. I could do no wrong. Just get on the throttle and go.

 

please correct my thinking, but the only way you'll experience understeer is if you're exceed the limits of cohension of the front tires.

that said, if you run a 265/305 for example, with perfect balance, then when you lose grip, you're losing both the front and rear at the same time.

going to a wide tire in the rear doesnt mean you wont be able to corner as hard, it just means when you do lose grip, you only lose it in the front and not the rear -- which might actually make recovery easier, no? Additionally, you can get on the throttle more confidently as you come out of the corner..

 

i do auto-x on 265/335 tires, -3f -2.7r camber, gt3 sways at medium holes, shocks set to 5 comp, 6 rebound - car is very well balanced, with just a hint of oversteer.

 

Agreed. The 235 and 245 upfront were not quite enough in the R888.

 

ah, i understand now. u think push as when you acutally lost grip. when u lost grip, you lost control. when i say push or lose, i am talking about the dynamic character of the car, when it still has full grip. it's relative grip, how much front vs how much rear, but never running out of grip front or rear. furthermore, it depends on driving style. i like a car to push and i find even with 255/315 it pushes. so if you run 245/325 it would push more, if i were driving it. sasportas drives 265/305 with aplomb, i will never run those b/c it will be too lose for my driving.

also there are many reasons why a car pushes, you only think about tires.
when you have big rear tire, yes, in theory you can apply throttle out the turn to go fast, but if front is too small relative to rear, you have no grip up front, you will not turn in right, if you can't turn in, you wont be able to get to apex then forget about exit.

with similar set up if the driver trail brakes very deep, then bigger rear will help with grip and still have good turn in. if drive brakes in straight line but turns in with lots of throttle, a small front will not turn in.

it's very set up and driver dependent.

 

FWIW - My favorite size combo for track is 245/35-18 F, 315/30-18R. Using Hoosiers R6 this set up is well balanced (can still power on full early push/ease power to rotate) with sways 1 from full stiff in front, full soft in rear.

 

I've been runing Pirreli Corsa 235/35-19 & 325/30-19 with a full Track Geometry for more than a year on my 7GT3.1

Absolutely no problems at all.

As for set-up, many people are opting to stay with std rear ARB on full stiff with 325 rear sections rather than go for a stiffer (GT2) ARB with std 305 rears to improve handling.

Good luck buddy, worked for me.