RJay

I'm in the process of stuffing a 993 3.6 motor into my RS Clone (~2100 lbs) and have begun to turn my attention to brake upgrades. The car is street licensed, but its sees little to no street use, strickly AX and DE. The car currently has S brakes. It would appear that the basic choice is either going with Boxster brakes or 930 Turbo brakes (This is so as I have 16" wheels and I'm loathe to convert to 17s...one has only so much money). I'm also debating the benefits of adding power or adjustable brake bias. Any opinions as to the benefits of the above combinations?

Bill Verburg

Since the Boxster setup is not much of an upgrade, I would advise full 930 brakes, or 993/S4 front calipers & 965 rear calipers on 930 rotors all around.

Your options are outlined here


Nice car by the way!

RJay

Thanks Bill for the pointer, the advice and the compliment!

N_Halbert

Hey RJay,
May be you sould just learn to drive it

Good to see your working on the whoa since adding all the additional go. Not that it needed more.

PS. while your at it, you may want to have them look at those wipers.

RJay

Geez Neil. Of all the people I know I would of thought you'd have a little respect for my car control skills. Refresh my memory, 7 out of 8 spins? You of all people should know Whitey's a very bad dog, and like most bad dogs, he's only getting meaner with age.

All kidding aside, I actually hadn't planned to go quite this far. I was debating between a 2.8 RSR style rebuild (expensive, but high revving fun) or a 3.2. Just happened along a reasonably priced nice 993 motor and I figured what the hell, I'll go for it. Given the noise restrictions at LCMT, LMP and now Devens, I figured I was better off having a more or less street motor rather than a racing one. Hopefully Whitey will be a little less finicky now that the big dogs been fed. (and yeah...I've got a new wiper motor coming too, although with this much engine and a little rainex, who needs wipers? Weren't you watching the Rolex yesterday? )

J.PELLEGRINO

RJay,I am in the process of doing a similar project for a client and he had 15" wheels.We converted the front struts to the late type and installed Boxster calipers on Carrera rotors.The original wheels did fit over this combo.He however is strictly a street car guy.We are the area Brembo dealer and they have a new line of brakes that will work on your 911 and at very reasonable prices.Give me a call or drop me a note if i can help.As for 930 brakes,I think you could do better with newer parts and modern technology.Good luck,Jerry

Bill Verburg

Yes, the Boxster calipers on Carrera rotors do fit in 15" wheels but there is very little benefit to doing that. The extra 4mm of rotor width will still be inadeqauate for the speed potential of a 993 powered 2100# car. For street use if you want the appearance fine, otherwise it's just not worth it especially when the additional cost of the mandatory rear upgrades(for that car) is added in.

And yes I agree that the Big Brembo kits are the best, I use that on my own car, but they do not fit in 16" wheels.

The newest GTP kit from Brembo is also quite nice, the front calipers are ~1# lighter the rear ~3# lighter, w/ a larger effective radius on the same 322mm rotors. But they still will not fit in 16" wheels. Additionaly I question the need for additional brake torque w/o additional tire traction. Nor are they particularly cheap.

For a light but powerful car the 304x32 and 309x28mm 930 rotors are sufficient. Yes, the technology is old, yes, having progessive pistons is nice and yes, 993/964 calipers on the 930 rotors is a better solution for 16" wheels but the 930 package is still competitive in function, price and fitment. A full 930 kit will come in ~$500-600 less than the full big Brembo kits and fit in 16s

Just my unbiased opinion of course, I am not in the business and am not trying to sell anything.

A930Rocket

Geoffrey

It actually depends on the 16" wheel. 993TT big reds will fit under certain 16" wheels. We ran them under BBS racing wheels at Sebring. I don't know about the Fuchs.

Steve Weiner-Rennsport Systems

Big Reds will fit inside certain modular 16" wheels of the correct shape and configuration.

They will not fit any 16" cast or forged single piece wheel,...

Bill Verburg

I've been told that they will fit is Design 90s as well, but the majority of users don't have these wheels. It also depends on the hub and fender. For instance I suspect that a '81-89 930 w/ most 16s might be able to get away w/ them.

The full Big red rotor/caliper package measures ~360mm(ie > 14") across and needs > ~60mm from the rotor face

Paul968

One alternative..... We now carry the brand new Brembo GTP-Light weight kits, which fit under a 16" wheel. This kit offers more rigidity, less unsprung weight and a lot more stopping power than the Big Reds....also they dispel the heat much better.

The big red, all though bigger than the GTP kit in size, is 15 year old technology that is now surpassed by the new style kits.

This GTP kit is smaller, lighter and yet yields more braking power than the Big Reds and TT Kits. The Big Reds have a tall hat with a large pad, Porsche designed them this way as they offer a longer pad life in that configuration.

The new GTP kits is a smaller hat with a smaller pad... the difference here is the amount of lbs per inch and the level of contact on the rotor.
This new technology means this kit now fits under a 16" wheel.

The price between the Big Reds and the new GTP is marginal and very much worth the extra money.

Paul R.

Bill Verburg

They came out w/ the GTP kit only because the molds for the Big Reds are wearing out and will not be replaced.

The GTP calipers are lighter by 1# front and 2.9# rear but use the same rotors as the Big Red kits.

The thing I don't like is the even bigger pistons 40/44 front and 28/30 rear. This makes the bias the same as the older Big Red 993tt kit which I and most other users seem to dislike. It appears that most of us have gone to the 993RS Big Red 36/40 front 30/36 rear.