924Board.org

bass gt · Posted: Sat Jan 06, 2007 9:45 am Post subject: Rear Brakes

Hi Guy's,

Another seemingly strange Q, but here goes!!.
Do any of you know the piston diameter of the 931 rear brakes??

Many Thanks,

Steve

-nick · Joined: 16 Nov 2002 Posts: 2699 Location: Cambridge, MA

54mm front and 36mm rear. I think that's from the tech/spec book.
_________________
1980 931S
15psi boost, MS-II, EDIS, 951 IC, custom intake, Ford 5.0L throttle body, Forge BOV, WB o2, G31 w/LSD, 964 wheels, 968 rear sway, Bilsteins, 200# Welt. springs. A laptop, and a partridge in a pear tree.
1991 964 C4 Cabriolet

Smoothie · Posted: Sat Jan 06, 2007 11:43 am Post subject:

Yessir, the little book says 54mm-front, 36mm-rear for the 5-bolt, 4 wheel disc setup.
-And for the 4-bolt disc-front, drum-rear arrangement it's 48mm-front and 19.05mm-rear.
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

bass gt · Posted: Sat Jan 06, 2007 12:42 pm Post subject:

Thanks guy's,

In case you are wondering, i am fitting a Tilton pedal box into the car, and need to calc what size master cylinders i will need.

Steve

bass gt · Posted: Sun Jan 07, 2007 4:18 pm Post subject:

Sorry,

Are the rears single piston, or one piston each side??

Thanks

sequential · Joined: 18 Nov 2005 Posts: 500 Location: BANNED

bass gt · Posted: Sun Jan 07, 2007 4:44 pm Post subject:

Hi Wayne,

Tilton reckon that if i give them the specs of the car, they can size it all up in one shot. Well thats the theory anyway. Will be nice to get rid of the servo assistance anyway...

Steve

Raceboy · Joined: 01 Mar 2004 Posts: 2326 Location: Estonia, Europe

If you need more piston diam. at the rears, you can use 4bolt front pistons with barrels, they fit.
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold

'84 924, turbocharged, sold.
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bass gt · Posted: Sun Jan 07, 2007 6:16 pm Post subject:

Raceboy.

Do you mean the front calipers from a 4 lug car?

Raceboy · Joined: 01 Mar 2004 Posts: 2326 Location: Estonia, Europe

ic932 · Joined: 11 Feb 2005 Posts: 1104 Location: UK

if i remember correctly you are using willwood 4 pots up front? maybe 951 brembo's and 951 (86') rear discs would work well with the wilwood front calipers?

it just so happens i have brand new 951 discs and mint 968 4 pot brembo rear caliper's for sale

....hmmmm

bass gt · Posted: Mon Jan 08, 2007 12:51 am Post subject:

sequential · Joined: 18 Nov 2005 Posts: 500 Location: BANNED

bass gt · Posted: Mon Jan 08, 2007 5:25 am Post subject:

sequential · Joined: 18 Nov 2005 Posts: 500 Location: BANNED