FormulaRX

I searched but mostly big reds came up. Are there any benefits to fitting standard 993 front brakes on a 964 C4? I might be getting a pair of front calipers for free. What is the size difference? Will I need to upgrade anything else being that this is going on a C4? Any brake bias issues? Lastly, is it even worth it? Thanks

DobermanDad

Interested in hearing what is said. I've been tempted by 993 calipers a few times. I don't know that the standard are much better than what we have, but they can be used with adapters and different rotors and pads.

tdiquattro

I think it depends what condition your stock calipers and discs are in? and how hard you drive the car?

For me this was an amazing upgrade, so much more stopping power, I had new discs and pads on the stock brakes although they had some pad lift they were operational - but the difference was big, so if yours are shot then it makes even more sense.

You should change the rears to 993 as well though to maintain a sensible balance. The 993 rears look the same and bolt up the same, but have bigger pistons in the calipers which gives better balance with the fronts. No need to change the master or bias valve if you have a C4.

I would say everyone should do it, the secret isnt just a few mm larger discs it is 30% on pad area for wear/heat, and 32? 34? mm (cant remember) thick discs for heat.

Netbug

993 NA rotors are thicker (32mm vs 28mm)
993 and 964 front pads are not interchangable.

964 C4 rear caliper is the same as the 993 rear caliper (cosmetic differences)

too much money to put a thicker rotor up front unless you plan to track it as you need a special bracket to accommodate the 993 rotor, or the rennline bracket for the 928 rotors. Hence why everybody goes big red up front for the larger diameter.

Chiefyb

http://www.911uk.com/viewtopic.php?t...asc&highlight=
Just completed this exact setup. Have a read of the last few pages, might be interesting...

Bill Verburg

There are 3 basic Brembo calipers that were used from '89 -98 on 964 & 993 some versions were also used on various 944/951/968/928 models

for want of official names, lets call then small, medium and large
small
all are axial mount, black and silver versions, black on 964 front and rear, use the same pads as the 930s ie ~98x44mm, they come in front versions of 28x298mm rotors and rear versions for 24x299mm or 28x299mm rotors. The front versions all use 36/40mm pistons, the rears 28/30mm or 30/34mm. The rears come in leading and trailing designs(each can be converted to the other by swapping bleeds and feeds)

medium
front versions are all radial mount, came in black and silver, pad size is ~132x48mm, all use 32mm thick rotors, rotor diameters were either 304mm or 322mm. pistons are 36/44mm. they came in leading and trailing design(as w/ the small calipers either can be converted to the other), There are 2 sub categories -those w/ extended mounting bases used on front 964RS and 964 3.3t, those w/o extended mounting bases used on 928/993 front. The extended base calipers were used w/ 322x32mm rotors. the flat base calipers on 928/993 w/ 304x32mm rotors.

The rear version was axial mount and only came in red. It was only used on the rear of 993tt, 993RS, 993RS/CS, 993Cup, 993RSR. The 993tt versions uses 28/28mm pistons all others use 30/36mm pistons. The rotor is 28x322mm.

large
aka 'Big Red' but they also came in black on 928GTS. all are radial mount. all use 322x32mm rotors. All use ~132x58mm pads, all have 36/44mm pistons.

So base 964 w/ 4 piston caliper f/r used, black
front small 36/40 on 28x299 rotors,
rear small 28/30 on 24x299 rotors
brake torque @70bar w/o p/v 1974nm/1139nm ratio 1.74, w/pv 1974nm/615nm ratio 3.210

base 964 w/ 2 piston rear
brake torque @70bar w/o p/v 1974nm/1309nm ratio 1.508, w/pv 1974nm/707nm ratio 2.793


964RS used, black
front medium 36/44 on 322x32 rotors
rear small 30/34 on 24x299 rotors
brake torque @70bar w/o p/v 2381nm/1390nm ratio 1.713, w/pv 2381nm/751nm ratio 2.640

964 Cup used the same brakes as 964RS but w/o p/v

964 brake upgrade paths
first decision
wheel carriers
use stock steel then you need caliper adapters for the radial mount fronts either medium or large may be used. Use either 964 or 928 or 951 or 968 rotors

use steel 964RS/964t steel, then you just bolt either medium or large to them. Use either 964 or 928 or 951 or 968 rotors.

use 993 aluminum wheel carriers, again either medium or large bolts to these but you need to use 993 rotors

use 993RS aluminum wheel carriers. as w/ the 993 carriers but you also need the 993Rs outer tie rod ends or o/s Tarret tie rod ends

next decision medium or large calipers in front
use 993 or 928S4 medium calipers, Then use 304x32 928S4 rotors. These are plain and not drilled. If you chose to go w/ either 993 wheel carriers then use 993 304x32mm rotors these are drilled.

use 964RS or 964 3.3t medium calipers and then you use 964 RS one piece 322x32mm rotors these are drilled. If using 993 carriers use 993tt 2 piece rotors these are drilled can also use Gyro disk aftermarket 993tt rotors.

use 993RS/tt big red calipers then use 964RS rotors or 928GTS rotors , there are both 32x322 but the RS are drilled and the GTS are plain. If using either 993 carrier then use 993tt 32x322 rotors, these are drilled and 2 piece hat/annulus

on a 964 any if the bigger fronts will require that the rear be changed to either 964RS 30/34 or 993 30.34 rear. These are the same caliper except for cosmetics both are black but there are some silver 993 versions used on 993C4

w/ medium fronts on 304mm rotors
brake torque @70bar w/o p/v 2230nm/1390nm ratio 1.604, w/pv 2306nm/751nm ratio 2.970

w/ medium fronts on 322 rotors brake bias as per 964RS

last option for those willing to give up parking brake
993RS front and rear 32x322 front, 28x322 rear
brake torque @70bar w/o p/v 2306nm/1618nm ratio 1.426, w/pv 1974nm/707nm ratio 2.640

Bill Verburg

Oh unless you have a C4 all brake upgrades will want to also install a 993 power brake booster and m/c, the 964 C4 comes w/ an adequate 23.8mm m/c but may wish to go to a 25.4 from an RS for better pedal feel.

The stock 964 20.6mm m/c is border line w/ stock let alone bigger caliper sets

FormulaRX

Wow pretty informative! Thanks for the detailed info!

FlyinTomato

fantastic post again Bill. should sticky it so we can all reference to it. You must be tired of posting the same info over and over again

doruiacovescu

Bill, do you know if standard front 993 callipers can be used on 964 c4 front with 16 inch wheel? Design 90

eddieb4

As I'm sure everyone knows, Brembo makes a direct Bolt on kit (at least for a C2). Parking brake works as it should. Custom ordered from Brembo in yellow.
355 x 32 fronts
328 x 28 rears
Man are they unbelievable! Overkill for sure but eye candy too.
I've kept and refurbished 46k mile originals to stay with the car when I sell.

doruiacovescu

Bill, do you know if standard front 993 callipers can be used on 964 c4 front with 16 inch wheel? Design 90

GeorgeK

Doru,
Yes. I use a 993 setup with 928 discs, they fit under any 16" wheel.

golfnutintib

bill v is the man

slight threadjack question -- for sane but sporty/spirited road driving (zero track use) are 964 c2 stock brakes worth upgrading (from a baseline of good condition rotors and pads of course...? i would think that even back to the early 90's that porsche put plenty of braking power on 911's, yes?

GeorgeK

No upgrade necesary with this type of use if your std setup is in good condition.