Brake Upgrade Clarification

[North Coast Cab]

I've been researching for brake upgrade options and every time I look I get a headache. I guess I'm looking for 930 calipers, but I just don't understand which rotors are used and if a ub change is required. I already have a 930 MC and I can handle the machining. Can someone help?

John

[trak ratt]

15", 16" or ?? makes a difference.

[North Coast Cab]

16"

[Bill Verburg]

15", 16" or ?? makes a difference

Doesn't make a bit of difference for 930 calipers. 930s fit in 15" x 7" or better.


Narrow car wants 0mm offset flat hats w/ stock hubs, w/ 304x32 mm rotor annulus. The rotor can either be oem(floating) or aftermarket. VCI or Rennsport are the 2 most obvious aftermarket sources, but their hat/rotor combo is not interchangeable. Best is oem , next is Rennsport, next is VCI(Willwood) There are other suppliers of the Willwood and/or Colman rotors in that size.

Other option is floating or non floating hat, floating for track, non for street or combination is best.

Only the 930 body cars will need a hub change to 930 hubs w/ the late 304x32 1 piece rotors.

rear rotors are straight bolt on, calipers of course need mods.

[RoninLB]

Originally posted by Bill Verburg

Doesn't make a bit of difference for 930 calipers. 930s fit in 15" x 7" or better.

Narrow car wants 0mm offset flat hats w/ stock hubs, w/ 304x32 mm rotor annulus. Best is oem ,

rear rotors are straight bolt on, calipers of course need mods.

perfect.. so in the past couple of days you gave more info for me than 6yrs of trying to find hard info.

so 4 x 7 x 16 911 Fuchs + 930 calipers front and rear is doable on a narrow body with fender mods ?

the 0mm offset flat hats w/stock hubs are the '78-'79 930 stock rotors bolted to a '77 hat ?

big thanks

[Bill Verburg]

I've posted the same info for the past 6yrs

[RoninLB]

well then it didn't sink in.

thx again.

[Bill Verburg]

There's alot of that going around

[Steve@Rennsport]

Originally posted by RoninLB
perfect.. so in the past couple of days you gave more info for me than 6yrs of trying to find hard info.

so 4 x 7 x 16 911 Fuchs + 930 calipers front and rear is doable on a narrow body with fender mods ?

the 0mm offset flat hats w/stock hubs are the '78-'79 930 stock rotors bolted to a '77 hat ?

big thanks

Ron:

You can fit 930 brakes on a narrow-bodied car ('69-'77) as long as the calipers are machined correctly and part of the outer fins are faced off for wheel clearance. You still might need a set of 3mm wheel spacers depending on your set of Fuchs. Any good brake kit should come with all the correct caliper spacers, mounting bolts, short lines, etc.

We've installed them inside 6x15" Fuchs on up,.....

As Bill said, you'll need the flat-hatted version of the front rotors ('78-'80 OEM; ours, or VCI's) on your stock 911 hubs and simply the stock 930 rear rotors (without splash shields) on the rear.

FWIW,......Our Brembo 305x32 front rotor assemblies are a lot more rugged and last FAR longer than the OEM Zimmerman full-floating units for any track or competition use. BTDT,...SOOOO many times.

Hope this helps,

[RoninLB]

Originally posted by Steve@Rennsport

Hope this helps,

absolutely

[rattlsnak]

I went with a 996 TT setup. They can be had for alot cheaper than Big Reds cause nobody used to make adapters for them, but now they do.

[Bill Verburg]

For lighter more normally powered cars another good more modern option might also be the GTP light setup

[Rick Ilcisko]

John, I upgraded to 930 brakes on my 911SC last summer. I wouldnt have it any other way. Bought the front rotors from Steve at Rennsport. Steve was very helpful and I would recomend his business to anyone. I live local and close to Cleveland if you want to meet up and see my install send me a PM. Rick Here is a pic of the frontsand a pic of the rears

[mpeastend]

Bill Verburg, you mentioned the Brembo GTP lightweights...which M/C would they need in a non-boosted car? 23.8mm? Mercedes or ATE? You had previously posted that the pedal would still be a little soft using them due to their larger pistons, is there anyway of firming it up other than a dual M/C setup in a non-boosted car? Would the bias and brake balance be such than I wouldn't need a proportioning valve for the rear in a 70 911, carrera flares, 2200 lbs, for the track or a modest one at 33 bar? Thanks Bill.

[Bill Verburg]

Bill Verburg, you mentioned the Brembo GTP lightweights...which M/C would they need in a non-boosted car? 23.8mm? Mercedes or ATE?

Yes. They are one and the same, buy a kit from Rennsport which will include several little bits and pieces to make the install easy.

You had previously posted that the pedal would still be a little soft using them due to their larger pistons, is there anyway of firming it up other than a dual M/C setup in a non-boosted car?

No, the GTP kits if they use the pistons described in the data I got from Race Technology will feel softer and actuate lower than a Big Red kit or a 993 kit. The only cure for that would be dual masters or transplant a hyd. boosted system. The GTP/L kit uses smaller 964 size pistons and when used w/ the 23mm m/c will have a very nice very high, hard pedal, one of the nicest I have ever driven w/.

The thing w/ bias is that it is dynamic, the bias at low speed needs to be very different from the bias at high speed, you can live w/ good basic bias at all speeds and it will work well. All the Race Technology kits have good basic bias. But bias can be tweeked to work better for specific situations. I am becoming more and more a fan of adjustable p/v on the rear circuit or for a pure race car, dual masters.

The GTP and GTP/L are fine w/o a p/v but can be tweeked to good effect. I do not like the fixed stock p/v at all but they can also serve a function.

The 33bar valve is way too aggressive except in the worst case bias situations

[mpeastend]

Thanks yet once again Bill V...your knowledge is invaluable. I'll definitely go with the GTP-LW's now based on your posting. I thought the lightweights had the same pistons as the GTP. Thanks much! Mike P