slvr993

Does anyone have the data on the weights of the 993 C2 and Big Red, front and rear calipers and rotors???

Mytrack car has lost a lot of weight and I'm considering switching to stock brakes if the unsprung weight difference warrants it.

Thanks
Jeff

IamSMC

Calling Bill Verburg

But in the meantime, have a read from his page:
http://members.rennlist.com/1976c38/brakes.htm

slvr993

I was sure someone would have this info given all the debate in the past.

Bill Verburg

front is 2.5# heavier/wheel or 10.4% inc
rear is 5.2# heavier/wheel or 24.76% heavier

you don't change to these casually or for looks

slvr993

Thanks Bill.

These numbers are for calipers and rotors combined?? Thats a lot of unsprung weight, but less than I would have thought especially up front?

Bill Verburg

It's the dry weight of the calipers and rotors, add a few pounds more for pads and fluid

Edward

You meant to say "the dry weight of the calipers and rotors," right?

Wow. I figured they'd be a bit heavier, but that is quite a significant difference per wheel, especially given that this is unsprung weight! Thanks for posting that, Bill. Makes me feel even better about the "little blacks" over the "big reds"

Edward

Bill Verburg

yes, I edited it to amend that little error. My mind was wandering trying to remember if I weighed them w/ or w/o pads & fluid.

the front pads are just a little heavier, the rears a lot heavier, but I sold all my old pads so can't weigh any.

KOAN

How much do you think unsprung weight can be detected in a street car driven on the track? I am considering lighter rotors which are much more expensive, and trying to figure out if they are worth it. I may do an A-B test, but I have to wait many months to find out. There may be a 3-5+ lb difference per rotor.

daveHy

Jeff, are you interested in swapping standard c2 brakes for big reds plus some cash ??

slvr993

Davehy

Sorry - I actually already have a complete C2 set of brakes. A good friend was kind enough to wreck his 993 at the track this year so I got a set cheap.

Jeff

Edward

I'd be willing to bet "not at all" on the street. As for being able to tell the diff on the track, I would think that would depend on how much the weight difference is per corner (where 3+ pounds of moving mass that has to change directions in milliseconds is significant; ounces not so much). Also what state of "tune" the car (or most notably, the suspension) is, and the conditions of a particular track. Closer-to-stock setup would likely make precious little difference, but with a taut track suspension and R-comps, a good driver could tell the difference at surface irregularities and/or bumps and dips, especially at braking or cornering. That said, I will let a truly talented driver step up and provide a more definitive answer

Edward

mcipseric

Are there any gains to changing to big reds from stock "black" on a standard C2 with no engine mods used 50/50 track/street?
I am guessing that the bigger brakes were meant to handle the extra power of the Turbo. Aren't the brakes matched to the car's weight and power... ? Please correct me if I am wrong.
I am a sponge! And a dry one at that :-)

Bill Verburg

there were 2 versions of the big brakes
993RS & 993tt used the same front calipers and same size(322x32) front rotors but RS were 1 piece and tt are 2 piece. everyone uses the 2 piece versions

993RS & tt rear calipers use the same pads(same as 993 front pads) and rotors(322x28) but have different piston sizes. RS has 30/36 tt has 28/28.

The RS has more rear bias that can be used on lowered track cars w/ stiff suspensions and effective lsds.

the point of the bigger brakes isn't so much stopping torque(though that is much better than stock) but to handle the heat generated during track use. The RS/tt brakes will last much longer than stockers because they run cooler, both in a given session and for total # of track days before replacement is necessary.

mcipseric

TY! Looks like I will be going TT BigReds next brake service.