Mark GT2

I don't know if they would shatter or not. Not being familiar with this type of rotor I doubted that they would warp - and my experience with ceramic - it normally shatters (doesn't bend). With the gouges in the rotor, we put new pads on, ran around the track a couple times, checked the rotors again and the holes were getting larger and deeper (quickly I might add). The flaking was like sand - the rotors were starting to disintigrate and this material continue to come out......it was a bit unnerving to say the least.

Steve in FL

Seeing as I'm the person that originally posted this response from PMNA (on funcarsonline's GT3 board) I think I should clarify it was in response to e-mail I'd sent asking about _track_ use of PCCB brakes. On the street one would expect them to last much longer. And if you look at the GT3 pages on Porcshe web site you'll see they have the following "disclaimer" about track use: "With its major weight savings and exceptional fade resistance, even at very high temperatures, PCCB is the ideal option for genuine competition use. It is important to note, however, that circuit racing or similar extreme driving conditions can significantly reduce the overall life expectancy of even the most durable pads and discs. It is therefore important – as with conventional steel high-performance brakes – to have all PCCB components properly checked and replaced, if necessary, after every track event."

brh986: For an explanation of "floating rotors" see http://stoptech.com/faq/data/faq18.html

MJones

Guess thats why theres lemon laws, and some people get lemons,
I read this PCCB thread and dont believe that Ceramic Composit is as prone to failure, as made out...Ceramic Composite Clutches for the C-GT
1500 track miles for rotors is a whole lot of abuse for any brake system

Chris Cervelli

I think you proved to yourself that the PCCB brakes are not going to work for you. I think your methodology was fair and you gave the brakes ample time and opportunity to get the job done.

They don't get the job done.

I have to believe that Porsche tested the PCCB system extensively with street tires. It seems like somewhere along the line, they would have outfitted a Cup car with them and seen how they take real abuse. Maybe this did not happen. That would be totally inexcusable.

You should get yourself some '03 Cup car iron discs and never look back. They are about $250 each and should last 25 hours or so even when you beat them mercilessly.

There is no way the increase in unsprung weight is going to affect the handling of a 3000 lb street car. That whole unsprung weight thing is totally overdone, anyway. If you look a GT3R what do you see?? A really light body (sprung weight) and huge brakes and huge wheels and tires. So the GT3R has a far worse ratio of sprung to unsprung weight than your GT2 will ever have. The GT3Rs seem to get around the Glen ok.

It is BS that you paid an extra $8K for brakes that don't work in the car's intended use. Porsche ought to take care of you for that least.

It is kinda funny when you think about. All the technology cars have these days, and the best brake discs are made of the lowest tech metal there is, cast iron.

brh986

Ben,

You make very good points but...

There are still a few reasons I haven't called to change my order yet.

Mainly despite all the horror stories the only places I've read them are message boards and I have read at least some that say the PCCB is great (if I remember right watt says they're fine). You always hear from people that have a bad expirience more often than those that have a great expirience IMO (this is not limited to porsches just in general when you think about it). I'm not taking delivery until june '04 and I figure they will either have to fix or discontinue these brakes if it's as bad as reported here. There is just no way Porsche is going to get away with a scam on this scale if it's really that bad. They've got to much to lose just to screw their customers for $8k on faulty brakes. I figure htey will either fix or stop fitting the cars with it. I'm wondering if maybe teh horror story people got a bad batch of rotors or something? I can't believe we haven't seen these stories published in a magazine if truly all the pccb are this bad. Maybe only 25% of them turn out this way? What does everyone think? WHy haven't we read about this in car and driver or something like that - if they are as bad as described here in every case then I don't believe they can pull of a scam like this without getting some extremely bad press.

JasonAndreas

I'm not trying to defend Porsche but every major racing sanctioning body specifically bans ceramic brake rotors.

JeffES

This thread/topic harkens back to a previous set of posts on PCCB.
It seems that there is much truth to the following comments:
PAG was in a "rush" mode to bring PCCB to market in advance of DaimlerChrysler,
The manufacturing processes for the rotors are yet to be sorted out (no, they won't shatter - they're CF. The surface is infused w/a ceramic compound),
"Early Adaptors" are indeed pioneers.

Other observations:
Eary advertising for PCCB included comments on fully metallic pads w/no common application to metal (cast) rotors. Where did those pads "go"?
Nowhere have I seen advertisment that PCCB's offered superior stopping performance. The "advantages" were to be in "Lifespan" and unsprung weight. (Contrary to what was posted above, unsprung weight is a very "big" issue. While there is no hard and fast correlation, an oft used "rule of thumb" is that a pound decrease in unsprung weight has as much impact as a 100 lb decrease in "sprung" weight, thus a possible advantage to PCCB.)

The solution either lie in the rotor itself, or in a combination of the rotor and "common" brake system operation(s). For example, ABS systems generally keep the pad in pretty good contact with the rotor during the pulse cycle.....

Interesting, to say the least. Keep us posted, please.

J

Sloth

Would love to hear what happens too... please keep us informed.

ldw

Chris hits the points right on the nose as usual... The cup front rotors take incredible abuse and last a remarkably long time-this can depend somewhat on pad use. I have always used Pagid orange with excellent stopping power in warm ambient and cold.
The greens are excellent, but we have found them to not last as long actually and rotors must be replaced more frequently.

On the GT3 street car, I now have 1100 miles(400 of that being on the track). The stock yellow pads have worn perhaps 15% maximum. The rotors have some very fine micro cracks extending from perhaps 40% of the drilled holes within the rotor.
They extend only a few mm and is completely expected following hard track use. The rotors certainly have several more track days in them and many thousands of street miles remaining.

JeffES

Chris,
Sorry, but you've hit one of my "keys". In a street car (not talking true race vehicles here, such as a Cup car), every gram of unsprung weight is an issue. The less the unsprung mass, the lighter (thus less $$) suspension components can sometimes be used is one issue, while the reduction in mass also allows the suspension to be tuned for good compliance with less compromise in comfort (yes, comfor is a big issue, even to co's like Porsche). It's a bit of a paradox, true, but unsprung weight is an issue that impacts more aspects of a true street car vs a track car.
Respectfully,
J

Sun Ra

you should be dealing with your regional PCNA rep., not your dealer. your dealer can tell you who this is, or you can call owner service at , if these are still current: 8005458039/770290/3500.

bring him into the issue and see what happens.. it's sounds like the dealer knows you've been tracking and that releases Porsche of substantial responsibility [no way to know how you drove the car] but the rep may still come thru. it's also not clear what your history is with the brand, whether you are are repeat customer which may help. the other issue is it's not clear you bedded the pads properly before you went to the track?

as i've said before, Rick perkins my exec. handler at PCNA says he's had one PCCB claim, so be the second!!! do not rely on your dealer as a final answer.

also while i have had 12,000 trouble free miles on PCCB in 3 cars, I do not track, altho' i use alot of brakes. we just inspected my current gt2's brakes after 3500 miles of very high speed driving with heavy braking, and at 6000 total miles they are perfect. Fixed wing has has alot of trouble with his, and another nameless friend of mine got free front brakes from his dealer in Europe

Sun Ra

btw,
oak is running gt2 calipers with iron rotors and loves it, and i'm sure he will share all the setup details if asked

Karl S

Jeff,

In theory you might be right. The realty is Porsche does not recalibrate the suspension settings if you get PCCB, so the advantages you state are not realized unless the owner spends some more money and does their own suspension tuning. The other advantage of less unsprung weight is sharper turn-in and a more responsive feel to the car. I suspect that there are very few drivers with enough track experience (you won't get it on the street) to be able to really feel 40 lbs difference in unsprung weight.

Karl

JeffES

Karl,
Of course, you're correct. What happens on pure "street cars" is that the product planners work w/the suspension engineers to peg suspension performance to the range of planned wheels/tires/suspension components.
This also points to me that the entire PCCB issue is not fully sorted out.
As far as turn in (suspension settings)- you're correct there as well. I've met dozens (hundreds maybe) who insist that they can tell, but I've only met a handful who actually could. I know I can't do it very often or very well.
"Responsiveness" is another issue. By reducing the unsprung weight, the forces on compression and rebound are a bit less, thus reducing the oscillations felt in the passenger cabin. Generally, the longer the wheel travel, the more the "impact" of unsprung weight. In other words, you'll notice the change in weight more the rougher the road surface....
J

Oak

Mark GT2,
To retro-fit steel rotors to your GT2, All you would have to do is use the MKll GT3 cast iron rotors 350mm front and 330mm rear respectively. A new set of GT3 Mkll rear calipers to get the caliper in the correct alignment for the smaller diameter 330mm steel rotors (PCCB is 350mm rear). (You could probably have the GT2 calipers machined.) That's pretty much it, front and rear rotors and new rear calipers. You can even use the P90 pads on the steel rotors, they work great with steel. Similar pad compound to the R19, the green compound is the same as R14. These both work great with the steel set up. They are easy on the rotors, great initial bite, High fade resistance, see
R19 and R14 pad compound