Q&A

It has been questioned and discussed here before:

I have finally had the time to take my 991.2 GT3 Cup out with 992 GT3 Cup tires:
Michelin Porsche Cup N3/R Slick tires:
Front: 30/65-18 Rear: 31/71-18

The fronts are a bit wider,
The rear tires are the same as for the 991.

They fit perfect !!! Do not rub anywhere.
ABS also functioned without any issues.

Drove it with my preferred set up originating from using the 27/65 Michelin Porsche Cup N2 front tires

I'm sure if i drove harder, the outer sides of the fronts would have completely been driven on the maximum width of the surface.
I now had around 1 cm that was not used. Sure if i also would reduce the camber slightly, they would have the maximum contact width.

It was worth the try as i have around 100 sets of these tires with around 100 km on it only.
So this is perfect for a trackday, testing and Club Racing use now



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wagongotya

amazing

carbondan

Fantastic.
The 991.2 GT3 Cup MR uses those same front tires mounted onto 991.1 GT3-R front wheels with no modifications to the front suspension (other than the upgraded dampers) and wider fender flares.
What ride height and camber settings do you like for the michelins front and rear?
I'll install a set of these on my next tire order.

Q&A

Camber:
FL: 5,50 FR: 5,52
RL: 5,06: RR: 5,04
Camber Spacers
FL: 18.0 FR: 18.0 mm
RL: 13.2 RR: 13.0 mm
Ride Height:
Front: 78,0
Rear: 103,5

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carbondan

Michelin recommend 11.5 to 12" rim for that tire. It looks like the 992 Cup rim is 12" wide with ET 23.5.
991 Cup is 10.5" ET28
991 Cup MR uses the 991.1 GT3R fronts 'without modification to the suspension' which are 12" ET17
Would the 992 cup front wheel fit and work properly?

Using an offset calculator, with numbers relative to a 991 cup at 10.5" ET 28
992 cup wheels would give 14mm less clearance on the strut side and would extend the outer edge by 24mm.
991.1 GT3R wheels would give 8mm less clearance on the strut side and would extend the outer edge by 30mm.

Q&A

Sure they will fit a 991 MR.
Even better then on a 991 / 991.2

Obviously the 27/65 in the front are better on a 991 Cup.
but with none of these cars running in top series, you won't be able to get little used sets from top teams anymore.
So the 30/65 is a good alternative, when you're not wanting to drive your car on the limit and have some fun on a trackday.
Handling is really good, no rubbing.
With altering your set up slightly, you can most likely even gain more out of them (have not tried so far)

The rear sizes on the 992 are the same as for the 991.
The fronts a touch wider. 30 vs. 27 which fitst the rim good.
No rubbing as i mentioned.

If you compare a set of Hankooks for the 991.
The have an almost similar width as the 30/65 front tire.
These all have a more 90 degree angle, mounted.

The 992 Cup tires on 992 Cup wheels have the more round angle.
Similar as how the 27/65 tires sit on the 991 wheels (OEM set up)

This explains the overal width extension when you add up all those differences.
Check the stag of wheels i have and what the height (= width) differences are

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lawlence

Bringing this thread back to life after doing some research.

It's the 991.2 GT3R wheels that have the +17 offset.

991.1 is +33 which would definitely hit the strut/spring.

8mm with the 991.2 wheels would be okay, there is about 13mm back there between the wheel and main spring, leaving 5mm for deflection which is plenty. Question then is where to source wheels... they do not come up often for sale!