964 Rear Calipers

[MikeHerman]

Hi,
Someone told me that in 1991 halfway through the model year, Porsche decided to change the rear brake calipers on the 964s. Is this true, and what are the before and after specs of the calipers?
Thanks,
MikeH

[Britwrench]

Early C2 and Tip cars have 2 piston rear calipers, all C4 have 4 piston versions. During 91, the C2 and Tip cars went to the C4 caliper.
You can easily see the caliper through the wheel.

[Pete000]

I just got finished swapping out the wimpy 2 piston units for the more impressive 4 piston set up. Nice thing is they share the same pad as the fronts. I used 944 turbo rears which are the same as the 964, but cheaper and easier to find. Just had to swap the bleeders and the cross over tube. Also did the bias valve from 45 to 55 also easy to do.

[Pete000]

Here ia a comparrison. FYI 944 turbo and 968 calipers work on the 964.

[Bill Verburg]

Originally posted by Pete000
FYI 944 turbo and 968 calipers work on the 964.

There are a couple of caveats that need to be mentioned w/ regard to this statement

1) There are some oddball 944t calipers that can be used but don't have the usual and expected 36/40mm pistons used on a 964

2) 944t and 968 use trailing mount calipers, that can be used on a 964 but the bleeds and feeds will need to be swapped to use in the leading mount 964 implementation.

3) the p/v will need to be swapped from 4 x 2 piston rear 45bar unit to the 55bar unit used on 4 x 4 caliper 964s

[LongDuckDong]

If anyone has a set of rear 4 piston calipers for sale I'd be interested. I'd like to get rid of the 2 piston calipers on my 90' BSER2@aol.com

Any clue is a set of rear calipers off of a 95' 911 would work without having to use adapters or change the valving?
Part #: 993 352 422-right 993 352 421-left


Thanks

[Pete000]

I don't think the 95's will work, but Bill can tell you better than me. He knows Porsche brakes like no other.

[Bill Verburg]

The '95 993 rear has bigger 30/34 pistons this moves the bias to the back.

You want 28/30 and the 55bar p/v instead of your stock 45bar

[LongDuckDong]

Thanks Bill, my search will continue......

[Kraftwerk]

Check out the article in Porsche Panorama July 2005, will demystify the topic a bit further. Interesting stuff..