TRM

Just a curiosity I have.

Hurricane

I can only speak for the Carreras, not the GT3s. I had a 2013 991.1 911S w/PCCBs and a 2018 991.2 911GTS w/PCCBs - there was quite size difference between them. The regular S steel brakes were also a little different in size between the .1 and the .2.

PCCBs for the 991.1 were 350mm front and back, the S brakes were 340mm front and 330mm rear.

On the 991.2, PCCBs were 410mm front and 390mm back. S were 350mm front and 330mm rear.

Litigator

AdamSanta85

991.1 and 991.2 PCCB are different. 991.1 are smaller, the 991.2 Carrera has the same size rotors as the Turbo and GT cars.

I am pretty sure the 991.2 Carrera PCCB are the same as Turbo PCCB. They are the same size (and maybe the same pad) as the GT3 PCCB but the uprights they connect to are different thus the calipers won't swap between applications.

Hinz Motorsport

@AdamSanta85 is correct. To expand...
991.1/2 GT3 PCCB - 410/390mm
992 GT3 PCCB - 410/390mm

991.1 GTS PCCB - 350/350mm
991.2 GTS PCCB - 410/390mm
992 GTS PCCB - 410/390mm

That said, the GT3 and GTS 410/390 rotors have different offsets as the uprights are different, so they are not interchangeable. The pad shapes used in all models above aside from the 991.1 GTS are the same, however.

atm75

Thanks for answering a question I always had in the back of my head.

So the only way to upgrade a 991.1 GTS to PCCBs is to either get hold of either 991.1 or 991.2 PCCB discs.

Are the 991.1 and 991.2 GTS calipers different too?

A related question: would upgrading the wheels to the GT3 wheels help resolve the offset issue?

Also, my understanding is that Porsche changed the compound between the disc generations and that the current generation (991.2 and forward) has less issues with heat related wear.

Thanks

Hinz Motorsport

If you have a 991.1 and want to stick with factory PCCBs, you would then need the factory 991.1 Carrera PCCB calipers.
991.1 and 991.2 PCCB discs are different, as are their calipers. The 991 PCCB calipers are designed for 350mm discs. The 991.2 PCCB calipers are designed for the 410/390 discs. That said, there is a range both calipers can operate in, but going from a 350 to a 410 is too large in most cases and vice versa. This is because the pad shapes the calipers take are different and are designed for specific disc annulus/radius.
The offset issue is in the wheel carrier/upright. Changing wheels won't do anything to change the hat offset required in the disc. If it fits, it is merely an aesthetic change but the 991 GT3s came with centerlock wheels, not 5-lug as most other 911s have.
Newer PCCBs (i.e. 911+) are better than old (i.e. 997-), but still have their limitations if driven on track. For street-only use, factory PCCBs will last a long time.

All that said, if seriously considering ceramics on a 991 GTS, we offer Surface Transforms kits that will work with your factory red/iron-based calipers. We have 350mm kits for both iron and PCCB-equipped cars. For the 991.1, we have a 350mm Kit front and rear that is a direct bolt-on. We also have kits for 991.1 PCCB-equipped cars and 991.2 iron and PCCB-equipped cars.

STs are way better than PCCB discs (better in literally every metric) and can be refurbished several times. With RSC1, it will be noiseless and dustless, with excellent bite, feel, and modulation. Discs cost $6957 per axle, and $13,915 per car, which is significantly less than new replacement PCCB discs.

IXLR8

Not according to my 991.1 GTS with PCCB. The Porsche Code production sheet which lists 340/330 mm. Also shown as that in the "991.1 Service Information - Technik Introduction.pdf". Maybe Porsche has it wrong.

Never thought to measure them since it stops extremely well, but the next time I have the wheels off, I will.

Hinz Motorsport

I believe 340/330mm are the sizes for the iron rotors, not PCCB. All 991.1 Carrera PCCBs were 350mm front and rear as far as I know. 991.2 moved to 410/390. I don't think Porsche ever offered any PCCBs smaller than 350mm, but I could be wrong. Can someone else confirm?

IXLR8

That is what was listed on the production code sheet showing all specifications along with the options and their codes. The S model also used the 340/330 mm set up so maybe Porsche messed up on my sheet.

I'll measure my PCCBs when the car comes out of winter storage.