Is there a comprehensive brake thread?

[Tippy]

I've had my 87 911 for 8 years now, and I STILL don't know what brakes my car has.

Any threads with full measurements and/or pics of calipers??

I have cross drilled ~290mm rotors (I think???) now.

[Trackrash]

There are so many different brakes available, it would be hard to catalog them all.

Post a picture of what you have and hopefully one of the experts will chime in.

[Matt Monson]

Search for a brake thread started by Bill Verburg.

[Tippy]

I searched 20 pages to no avail. I did find an old link to Rennlist, but it was dead.

I'll post pics later when I have time.

[Bill Verburg]

Originally Posted by Tippy

I've had my 87 911 for 8 years now, and I STILL don't know what brakes my car has.

Any threads with full measurements and/or pics of calipers??

I have cross drilled ~290mm rotors (I think???) now.

specs are here

These are A & M calipers w/ matching 20mm rotors, '87 would be visually the same, probably cleaner, from '84 the calipers had thicker spacer in the middle and used 24mm thick rotors vs the earlier 20mm thick rotors. The rears also got bigger pistons(42 vs 38mm) and a 33bar p/v was added to the rear circuit.

[Tippy]

Thank you Bill! Definitely not stock then as I suspected. The fronts say PowerHaus, but the numbers don't show up on a Google search.

Let me post some pics so I don't waste anymore time.

[Tippy]

First 3 are front, last is rear.

I think I measured around 11.4"s for both, but don't remember if that's accurate or not.

Anything spring to mind if source Porsche model?

[Tippy]

Morning bumpity bump

[Bill Verburg]

Originally Posted by Tippy

First 3 are front, last is rear.

I think I measured around 11.4"s for both, but don't remember if that's accurate or not.

Anything spring to mind if source Porsche model?

the fronts are the big ones used on 993tt and 993RS(some versions of 928 and 964 also used these) aka 'Big Red' they have 36/44 pistons and want a 322x32mm rotor, min rotor thickness is 30.6mm

the rear appear to be 993 normal rear though there are other versions of that caliper that have been used, if they are 993 rear they have 30/34mm pistons and oe are used on 299x24mm rotors they can be fitted to a 911 trailing w/ some effort and can be used w/ a 930 rear rotor 309x28mm(that is what you appear to have) There are several ways to adapt the caliper to the 911 trailing arm, one common method is to fill the oe mounting holes and redrill

it will look like this from the axle side



the other method is to machine off the mounting ears and convert the caliper to radial mount w/ a caliper adapter
that would look like this
from left stock 993RS axial mount rear caliper, center 993RS rear caliper converted to radial mount w/ caliper adapter, stock radial mount 993RS front caliper, your rear is smaller but the method is the same.

[Tippy]

Thank you Bill! So a lot of folks when posting these same pics stated they were not Big Reds due to the smaller rotors. Can a smaller rotor be used with the BR calipers? Different pads?

Sorry for the dumb questions.

[Tippy]

I just reread, so you can use different rotor sizes with the same caliper.

[Bill Verburg]

Originally Posted by Tippy

Thank you Bill! So a lot of folks when posting these same pics stated they were not Big Reds due to the smaller rotors. Can a smaller rotor be used with the BR calipers? Different pads?

Sorry for the dumb questions.

Maybe but much smaller than 322 w/ a big red the pads start to hang off the outer edge and the inner rubs on the hub.

here is a pic of 993RS/tt 322mm rotor and calipers, this is the back side but you can see how close the caliper is to the hub


here's a pic from the front


the 993 used a shorter caliper and 32x304mm rotors

this 993 normal front on a 32x304 has been painted they are black for C2 or silver for C4 this can be used on a larger rotor but not the other way around


the 993RS/tt and 993 normal front calipers look similar(ignoring the color), the 993RS/tt is thicker looking from the side and has a hump in the middle
normal 993

RS/tt 993, not thicker appearance and hump

[Tippy]

Thanks so much, Bill! You always come through on this stuff.

[Hcarraro]

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Henry