LFA

Hi,
Planning to upgrade my stock brake rotors and calipers on my 91 GT and 88 S4.
Both will have 17'', Cup 2 GTS wheels. Can I use any of the Porsche 911 rotor+ calipers with these wheels.
Thanks.
Evren

The Forgotten On

Stick with the 928 rotors, the 911 rotors don't have the correct offset.

Any 911 4 piston calipers will fit if they are from the 993 back as far as I know.

Any of the calipers including the big reds/blacks will fit under the 17 inch rims.

LFA

Thanks,
Just to understand your advise; if the rotor diameter will not increase , do you think changing the calipers might improve braking?
I have my stock rotors and calipers, now that the wheels will increase from 16inches to 17, I was thinking, can I use this extra space to improve my brakes.

The Forgotten On

In order to see an upgrade in braking you will need to dissipate heat quicker, which means a bigger rotor.

So you will need bigger rotors from a GTS or a better pad compound to see better results with the better brakes.

I think a few people run the rotors off of a Ferrari F50 on their 928s, they are even bigger than the GTS rotors The 330 Cayenne rotors are another good option to run on a S4 as they are cheap.

Running 911 brakes wont provide any improvement over 928 S4 brakes unless they are the big reds or blacks.

LFA

Thanks, Cayenne rotors is an interesting option. Can you also use the Cayenne calipers?

The Forgotten On

There was a thread on that at some point, I don't know the results of it though.

However you would need 18 inch rims to fit the massive 6 piston calipers under them and then it would be a lot more difficult to find a good pad to use...

Ad0911

Nice going Evren! While some of us find it deifficult enough to fix one car, you have 2 at the same time in apparantly the same status of ground-up rebuild. Must be more efficient this way. Not mixing up the parts would be my headache! Do you use a strickt divider leftcar / right car?