Will

I’m curious about how drivers of ‘84-89 Carreras in F-Stock manage to deal with the limitations of the stock calipers and rotors on these cars. I believe F-Stock allows pad/fluid/cooling modifications, but no upgrades to the calipers/rotors.

My question is this: I’ve heard that in F-Stock, “brake management” must be used, i.e., one has to live within the limitations of this weak link, driving in such a manner as to not overheat the brakes, perhaps letting your competitors go for broke early in the race only to polish them off when they’ve overdone it later. Can any of you F-Stock drivers with experience on brake-intensive tracks share with us how you drive in order to stay within the limits of your brakes? For example, at Gingerman, serious speed can be taken into turns 1, 5, 10, and 11, with semi-serious speed into a couple of other turns, and threshold braking into these turns will exceed the heat capacity of stock Carrera rotors in a heartbeat, particularly on cars with well-set-up suspensions and sticky rubber. I know they have PCA club races there - any of you F-Stockers care to weigh in with your experience?

Thanks,

Will

Sloth

I ran an F stock 87 Carrera at Sebring and at Road Atlanta this past year.

At Sebring I really had brake cooling problems. My mach bled the brakes a few times during the weekend and added some cooling ducts that helped a bit. However, the brakes were always a weak spot that I had to be aware of. Sebring is hard on brakes to say the least.

At Road Atlanta the mach drilled the rotors, replaced the pads, and rerouted the braked cooling ducts through the fog lights. I did not have anywhere near the brake issues that I did at Sebring. However... different course so it would be hard to make a direct comparison. I still could feel the brake pedal getting a bit soft toward the end of a session.

FYI: Per the rules for stock class cars...
-Pads material is free
-Calipers and rotors must be as supplied by the factory (size)
-Grooving/ slotting/ drilling is allowed
-Air ducting and removal of backing plate/ dust shield is allowed
-Brake fluid is free
-master cylender as supplied by the factory w/ updates for early cars to tandom master for duel circuit system (safety)

Hope this helps. <img src="graemlins/jumper.gif" border="0" alt="[jumper]" />

Tony'z911

I'm hoping to get into Club Racing in a couple years and was wondering if cross drilled, slotted, or both is recommended? I have heard that drilled rotors have a tendency to crack under excessive heat, but how about slotted rotors? If non stock rotors are better then what do you recommend? Do you have stock rotors drilled or slotted or do you buy a brand that sells their rotors that are cast or forged with slots or holes?
Thanks,
-T

Sloth

[quote]Originally posted by Tony'z911:
<strong>Do you have stock rotors drilled or slotted or do you buy a brand that sells their rotors that are cast or forged with slots or holes?
Thanks,
-T </strong><hr></blockquote>

From what I have come to understand... you want to purchase the rotors with the slots or holes cast in them rather than actualy drilling them out. Stock rotors that are drilled are most likely to crack.

Anybody else have further insight on this?

Clarification... the drilled rotors on the 911 I used at Rd Atlanta were cast with the holes in them. Same size as stock.

James Achard

Sloth, Yes, Stock rotors that are drilled will crack. The holes need to be in the casting in order to avoid this problem(somewhat).

Cheers, James

Steve Weiner-Rennsport Systems

Hi Gents:

Just a quick datapoint about the SC & Carrera rotors that are made by ATE, Zimmerman, and Brembo.

Any of these that you see with drilled holes in them were not cast, they were indeed drilled.

The only rotors that actually have cast-in holes are the much larger ones found on the 930, 993 and TT cars.

These small 282x22mm and 282x24mm rotors had those holes drilled after they were cast and machined.

Caveat Emptor on these small drilled rotors.