wrs

Ceramics don't fade at the track and if they aren't allowed to overheat, the rotors will not oxidize which is the main source of degredation since the pads are what take the wear. As I said, I just changed my pads and they had 80% wear left on them but they crystallized from the heat and were making a rasping sound so it seemed better to replace them than risk damaging the rotors. If you let your pads run below 50% then you risk damaging your rotors. Clearly $700 for a pad replacement job is a lot cheaper than $12-$14,00 to get the front rotors replaced.

The other issue that my shop is planning to look into is cooling. If there is an enhanced cooling solution then it's worth it for cars that are going to be tracked very much as again, it's the heat that can cause oxidation of the rotors and that is what degrades them. Heat has to be over 1500F in order for the oxidation to begin and so a hard track day could do this. Maybe that is why Karl's rotors look the way they do, after all, he has 25 track days and he still hasn't told us how many sets of pads he has gone through.

Brake fade is dangerous and I for one would prefer to be safer at the track as I am nothing more than an amateur out to have fun and stay safe. If it costs more to be safer then I see no reason to scrimp. Ceramics don't fade but steel does and brake failure causes crashes. Just recently had a Corvette crash at turn 12 after the long straight. The driver got out alive but his car was destroyed and it was due to brake failure.

worf928

How many track days do you get out of 20% of a set of pads?

wrs

Two. However, the second day it was 100 degrees outside in September and it got very hot in the afternoon. The first day was in July but it only got to 95 but it was still hot. Keep in mind that is actually 40% since you aren't supposed to get below 50% anyway. They were 80% when I started the second day, probably less by the time I was done.

speed21

Not surprisingly, there are a few loose ends with the story.

Either way, and costs aside, I wouldn't swap my ceramics for steels any day of the week. The benefits are just too good.

worf928

Ok. Assuming you are observant and dilligent about pad changes so as to not prematurely wear the rotors how may track days do you think you can get out of the rotors (and what supporting data do you have?)

Also, do you have data on the wear rate difference front to rear or is it the typical 2:1 F:R ratio.

I'm interested in doing the math.

wrs

I don't know that I will do 25 over the life of the car. I will have done three by the end of this year. I may do three more in the next six months after that. Then I will be able to solo and my bet is that I don't do more than 4-5 per year anyway so 25 would happen at the end of life for this car. I don't plan to have it past five years. Maybe a new set of rotors is in store by then. I have no data for any of this, Karl is our only member who has reported on this issue so far. I just want to get as much from the rotors as possible and I kind of don't think Karl did but that is just my guess.

AndrewP

Are PCCB's worth it? Absolutely if you track your car. Porsche grey iron rotors are excellent brakes and so far I have not seen any recent 991's have trouble with overheating on track with them. This is not the case with grey iron rotors on all cars, however. Maybe the lower unsprung weight makes little difference to amateurs in lap times, but the PCCB's are optimal for the 991 in lower weight and braking performance.

RacingBrake

Iron Conversion:
http://www.racingbrake.com/RB-Iron-R...por-irk-03.htm

PCCB Replacement:
http://www.racingbrake.com/RB-CCM-Re...por-crk-01.htm

pccb discs are made by Surface Transforms.

Learn how these discs are made...
http://www.surfacetransforms.com/cp5.php