Calling SWB brake gurus...

[mjmoran]

OK, Just decided to turn my 68 into a DE/trackish car. The stock brakes on her seem to last me only about 10 laps and then are toast for the day...granted this is with stock pads, but I need some cooling! Anyway, what are my limited possibilites of new rotors and calipers that fit the spacing and early struts? I do not want to go to new style Carrera struts, although I know that that is the best method. I have heard that 944 rear rotors fit. I guess I would need to put a spacer in the caliper though since mine are non vented.

TIA

[ttweed]

Hi Mike-

Nice meeting you at the Speed festival last week.

My prescription for dealing with brake fade is as follows, based on your desire to keep original equipment:

Start with the cheap things and add fixes progressively until you can do a full session with no problems on the hottest days. The first things to do are to make sure you are using high temp pads that can stand the abuse of hot lapping and that your brake fluid is fresh and has a high boiling point, and that the system is bled perfectly before you start. The next thing to do is to duct cooling air to the brakes. This can be done with some cheap tubing and tie wraps, if need be. Take your inner dust shields off if you haven't already done so, and devise a way to bring cool air from the front air dam under pressure to blow on the calipers. Next would be some of the titanium backing plates from Sherwood to isolate heat transfer to the fluid. The final cheap upgrade is to learn to brake correctly on the track, so that you are not inducing more heat soak than necessary to the fluid.

From there, it gets more expensive. Using the vented rotors from the later models would be next. These were the same thru about '83, I think, and are very cheap and readily available. Channeling the cooling air into the center of these discs, using backing plates in the hubs to prevent the air from spilling out, will force the cooling air thru the vents of the rotor and blow it out into the throat of the calipers. It is a much more effective way to cool the brakes than just a hose aimed at the caliper. You may have to change the aluminum hubs too, I believe, to account for the change in thickness of the vented rotor.

There are several calipers that can be used with the 3" bolt spacing and this rotor, including the early "S" model ATE caliper and a similar one from the early BMW 2002, or there is a Girling 4-piston caliper that is very trick but quite a bit more expensive. The 944 part you are thinking of is for the rears, I believe. The vented rotor from an early 944 will fit there with a bit of machining to the outside edge. The rear vented rotors are a '67-68S-only item and QUITE overpriced.

Good luck with the '68!

TT

[mjmoran]

Thanks Tom...took the 68 to the track today and I could not believe the difference in brake compaired to the 67s with vented rotors. Our track up here has some pretty high speed areas ending with hard braked turns so it is hard on brakes anyway. I have ATE super blue and regular ATE pads although I do have some type of backing plate on the pad itself (I will check on the type of metal). This 2002 type disk may be the answer. I could also do the 67S type. Just fab out a spacer in the caliper. She was loads of fun today although I think the Carrera will be making an appearance tomorrow so I get more track time -- no waiting for the brakes to cool.

Yes, It was great to meet you and the other guys last weekend. Lets plan on better weather next time though.

Cheers,

[mjmoran]

Just found out why my brakes were so bad...one of each of the pistons had frozen up on the front. I only had single piston calipers!

Anyway, these calipers are the same as the rear ones on my Carrera...so anyone tried putting Carrera rears with Carrera disks on a SWB? These would have tons more heat sink than the stock and a larger piston to boot!

Now, what to do for the rears??? Maybe SC calipers or ???

CHeers,