cobalt

I would suspect a 355 would fit but would be tight. Is there concern for cooling when there is such little open space in the wheel? I went to the brembo site and I only saw a 328mm rotor offered as part of the package. I guess you can opt for larger or I missed something. I will be pumping out about 500 WHP I hope my 322's will be enough up front. The newer GT3's run a 380mm, the old big brakes are tiny by modern standards but it is mostly about the clamping force and pad compound. Hopefully I won't see fade but had no issue when the car only put down 350 whp with 2 drivers.

964George

I pulled this info from the Brembo site and associated PDF link below.

Fronts
PORSCHE 964 CARRERA 4 1989-1994 F GT 4-Pistons Cast 2pc (B, R, S) 2-piece disc 332x32
PORSCHE 964 CARRERA 4 1989-1994 F GT 4-Pistons Cast 2pc (B, R, S) 2-piece disc 355x32
PORSCHE 964 CARRERA 4 1989-1994 F GT 6-Pistons Cast Monobloc (B, R, S, Y) 2-piece disc 355x32
PORSCHE 964 CARRERA 4 1989-1994 F GT 6-Pistons Billet Monobloc (GT-R) 2-piece disc 355x32
PORSCHE 964 CARRERA 4 1989-1994 F GT 6-Pistons Cast Monobloc (GT-S) 2-piece disc 355x32
Rears
PORSCHE 964 CARRERA 4 1989-1994 R GT 4-Pistons Cast 2pc (B, R, S) 2-piece disc 328x28

https://www.brembo.com/en/Varie/Brem...ust%202019.pdf

Spyerx

the front brakes on my 997rs are 380mm and i run 18” bbs e88 on it. It clears. It’s tight. The front calipers have lots of rubber rash from track bits gettin between wheel and caliper.

You could talk to race technologies or surface transforms on options for custom carbon ceramic rotors. I have a Brembo race tech big brake kit the front is a 993 part to work with all the 993 bits the rear also they confirmed at time these would fit and bias was good and would clear wheels it’s tight but not as tight as my 997rs! 18” are required. Heat is not an issue there is so much thermal capacity u less you are driving the crap out of the car race pads barely get to temps on track.

i put a big package on mine in anticipation of a monster motor. And i like to stop this thing has insane braking ability. It’s really amazing actually.

and remember if you are putting the 993 front end spec the 993 braking system.

the 4 piston Motorsport caliper is also a really nice option. I think it’s a 328 f/r

they whole package is lighter than factor as while the rotors are larger the calipers are forged in front and the hats are aluminum. And yes the parking brake works,


1M2.8001A – 355x32mm slotted, w/6p Monobloc: 28/30/36mm pistons

2C2.6017A – 328x28mm slotted, w/4p: 28/30mm pistons

ForeverCar

Thanks! Good to know that even 380mm rotors have a possibility of fitting. I doubt I will go that large. Surface Transforms has 355mm that might be good if I find the right hat. Same for the rear. Not having parking brake would be okay but I would prefer to have it (glad to see the Brembo kit has parking brake).

Besides weight, low dust is the other minor factor.

As with most of the build, cost gets very high very quickly though. I am starting to get discouraged by the cost of a very lightweight build.

964.4L

Mine are identical Spyerx. Sorry to go off topic, but did you use the standard 964 master cylinder or did you have to change anything?

chsu74

Will oversizing the brake system not heat pads up properly on this lighter street car build?

ForeverCar

I am curious about this too. I plan on consulting with brakes experts like @RaceTechnologies and @Essex. I would imagine a street use friendly pad setup should work. Something similar to stock PCCB pads works decent from cold.

ForeverCar

Resurrecting my own old thread here. I think I might have found a path forward.

I will share more as I make progress.

s65e90

I need to weigh my car, but I'd suspect it's right around this weight. No AC/heat/sound deadening (does have lightweight carpet), and all fiberglass panels and door windows are plastic. Front/rear factory glass, light wheels.

ForeverCar

If you end up weighing your car, please share the numbers. Thanks!