DANACO

Hey there, what wheels are on your modified body, lower picture, are they the ones Tire Rack sells ?

4 Point 0

Yes. It’s funny, I don’t suffer any warping or buckling, or fade. The only symptom is the calipers discoloured. We are actually starting to think its just a coating failure and nothing more.

Wheels are stock Porsche GTS CL.

DANACO

👍
9x20 F ?
12x20 R ?
if so what size tires are you running ?

4 Point 0

Yep.

265/35/20 Eagle F1 Supersport RS I have E-Motion adjustable control arms and Tractive coilovers with tractive top camber hats. Running -4 degrees camber.

305/30/20 Cup2-R. At present.



-4 Camber front

DANACO

Thanks !

4 Point 0

Stock heat shield




Custom Trimmed


I’m not removing the heat shield, simply trimming it up like I do on my track cars. This will then still protect the speed sensor and ball joints from the scorching radiant heat of the rotor when your on track.

Jony++

So, does the 265x35x20 fits in the stock rim well?

I love my 4GTS, and if there is one thing I would like to improve is the front handling, that's why I'm following your post with attention. Thanks

4 Point 0

Yes, the tyre fits well. However you need adjustable control arms, to adjust your castor or they will rub on the inner guard lining.

Jony++

Ok, makes sense, there is not much room for the tire.

In your opinion which is the biggest improvement in the front axle?

4 Point 0

E-Motion

These, so you can increase neg camber.

Sway bars are good and needed, but to save your tyres, you need the neg camber, especially for tracking.

DANACO

So you have 305/30-20 on 12” rims ? Interesting, do they fit the rims ok ? It’s not a recommended combination, not even 315/30’s are which I find odd.
I have a new to me 19’ 991.2 turbo s I would like ( there’s a set for sale in the classifieds here) to put that style wheel on but am reticent on the 12” wide rears from what I read in the Tire Rack fitment chart.

Jeahbladejeah

@DANACO As of about 6 months ago, Tire Rack still didn't distinguish between 991.1 and 991.2 wheel offsets so I wouldn't put too much faith in their numbers. Doesn't mean it's wrong, just take it with a grain of salt and confirm elsewhere. 305/315 should be no problem on 12" rims.

DANACO

Where might you suggest I look elsewhere for fitment advice ?

Jeahbladejeah

Depends on what car you have and what you're trying to accomplish I suppose. New wheels & tires? Or just tires? Lots of threads here on Rennlist, just buried. The search function is pretty good after you learn how to use it with relevant modifiers for your car.

Here's an older thread re: difference between 991.1 and 991.2 fitments: https://rennlist.com/forums/991/1126...rrera-t-2.html
Can also play around here to learn more: willtheyfit.com

DANACO

My inquiry is to determine whether a 305/30-20 or a 315/3020 tire is acceptable on a 12” width rim. I just called Michelin and for both tire sizes the widest they recommend is 11.5” There are folks on this forum that do put those sizes on 12” rims without incident but wonder what the consequences might be in doing so. Stretching a tire I believe is not a good thing as it changes the intended shape of the tire both at the sidewall and across the section of the tread not allowing it to perform as intended and how it might affect wear. The question is, is 1/2” wider significant or inconsequential to the latter concerns ?