Question 4 Brake Guru’s (Bill V)

[Slider79SC]

I am building a car to use for DE’s and maybe some Club racing here and there so I need some insight on configuring a braking system. I would like to keep the cost down as this is being built on a tight budget, so I don’t want to go super elaborate.

Here are the specs on the car:

1969T with full RSR body
2200 lbs. With full GT class cage
1985 Carrera suspension with Bilsteins
22/29 T-bars
Racers group adjustable sway bars
Re-valved Bilsteins
16x8 & 16x9.5 Forgelines
245 & 265 R compound tires
Elephant racing bushings
220 hp 3.0
Short geared 915 with LSD

So what are my best options without going overboard on cost?

Thanks everyone….

[Jack Olsen]

I'm no Bill Verburg, but I'd say Carrera brakes (with race pads, and some ducting for cooling) should stop a car that's that light without too much trouble, and also not add a whole bunch of unsprung weight.

[Slider79SC]

Thanks Jack,

Your opinoin is valued very highly around here and for good reason.

Do you think this would be good enough for a two driver car at DE's? I don't have plans for big HP for now so I do see your point.

Thanks again....

[nestorjw]

if u do feel like spending some more, i have a C4S big red kit...

[Rot 911]

I'm with Jack. The Carrera brakes handle cars weighing 400-500 pounds more than yours at DE's without additional brake cooling. But cooling ducts are pretty easy to fab and don't cost much money so I would say add them. Big Reds would be overkill unless you are doing some serious racing.

[ChrisBennet]

I know it's "obvious" that bigger brakes weigh more but has anyone compared the weight of of a cast iron Carrera caliper to a say an aluminum 993 caliper? The larger rotors probably make the big brake setup heavier but I wonder if its as much as you think. Those Carrera calipers are heavy!
-Chris

[RallyJon]

Not to mention the weight of the rotors. It amazes me that no one offers a two-piece replacement rotor for 911s. The 304x28mm AP rotors on my Subaru weight less than the puny stock rotors. Talk about a no brainer...

[Mike Feinstein]

Will be upgrading my Carrera to 930 brakes next month. Looks like I'll have calipers, pads (pagid orange), cooling backplate and rotors available if you need them.

[masraum]

I think you can replace Carrera Calipers with Al S calipers. The rumor is that the S calipers were wider for the use of thick endurance pads and because of that they will fit Carrera rotors.

[Bill Verburg]

Since you're no longer in a stock class anyway,

993 front calipers on oem brembo 930 front rotors(custom hats and caliper adapters are readily available), 965 rear calipers (or 993 rears in a pinch, the 965s are sorta rare) on stock 930 rears, 23.8mm ATE m/c # 3.2123-1003.3, Goodridge ss lines, Padgid RS4-4 orange pads(Pagid RS14B black if you don't mind replacing rotors more frequently)

There is ~5# difference in weight at each front wheel from the above setup and stock iron rotor w/ A caliper. the small sacrifice in weight is well worth the additional thermal capacity.

The bigger tires will also be able to better utilize the higher torques supplied by the upgraded brakes

[beamonk]

I didn't know about using the carerra rotors with the S calipers. Would you have to use the SC pads b/c of the rotor thickness differences?

[Bill Verburg]

Fitting S calipers on 24mm Carrera rotors is similar to fitting 993 rear calipers on 28mm 930 rear rotors,i.e. lots of pad grinding is necessary and possibly some aluminum from the throat as well. At the rear it's not as big a deal because the thinner pads are less stressed than at the front. Thin pads at the front are not a good thing.