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Old 06-22-2004, 09:56 AM   #5
st-anger
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posted by jon_s:

Mr St-Anger, I was woundering if you could cast any light on a slightly sore point as far as the UK press is concerned.

It concerns the life of the ceramic brakes, which are supposed to have a service life of 186,000 miles ( -is that right!) but are lasting significantly less than that (In some limited cases) Cost of replacement is a whopping £27,000 (Enzo brake territory!).

Porsche are apparently claiming that track days are the problem! What exactly did Porsche expect their owners to do!

I sure hope there is a fix in the pipeline, as £27,000 to replce them is quite frankly taking the piss.


:arrow: … a good statement in that context: PCCB´s are a political hot potato within PAG”
now that´s a fact, that there´re some problems, or better, had been some problems…
to quickly answer your first question: yes, under “normal” driving conditions PCCB´s do have a service life of up to 300.000 km ( ~186.000mls )…
when they´re used on the track they sometimes have to be replaced after 10- to 15.000km ( ~8000mls )…
there´s been a huge discussion, some dealers changed the rotors under warranty, some not, especially in the USA....don´t ask me why???
so PAG added this disclaimer:

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.

therefore, anyone using the PCCB brakes on the track must be prepared to replace all components after each track event. cast iron rotors are cheap consumables but ceramic composite rotors are most certainly not! ergo, a track car is exactly the sort of car which should not have PCCB brakes. there are good reasons why you will not find these brakes on any of Porsche’s race cars…
there are three main problem areas with ceramic composite brakes:
first, the rotors overheat and fail.
second, the ABS system has not been modified for the PCCB rotors which causes less than optimal ABS performance and also damages the rotors. third, the pads are not able to handle the heat and are quickly destroyed once overheated. the lower unsprung weight that these brakes offer is noticeable as is the total lack of fade. and I do believe that ceramic-composite brakes offer tremendous potential, but Porsche introduced them too soon and they are just not ready for consumer use.

just read this:
DC introduced a ceramic brake pretty similar to the PCCB on a special limited production CL 55 AMG, called “F1 Edition” model. By that time, Mercedes had high hopes and big plans for introducing the ceramic compound brake on other models too, but they didn't.
and here's the question: why didn't they do it?
remember: we're talking about a multi-billion dollars super car manufacturer with billions of dollars of production/research budgets...

so, one major issue regarding PCCB development was cost, so they tried to adapt the current brake system with all components to the PCCB. same applies to tires.
a perfect and optimized PCCB system would require different components (incl. completely different electronics and mechanial parts) and of course optimized tires, not to speak about the pads which could be better but also much more expensive and no one would pay 1000 bucks for one set of pads which last 2500 mls.

PCCB works pretty well on the street, even if it needs some temperature to achieve best results. as far as replacement/maintenance cost is concerned, I think we can't blame a manufacturer if a brake isn't "track worthy", actually which brake is "track worthy"? even the beloved 380 mm steel discs need replacement after some tough track runs, so right now, the PCCB is at the beginning of development, it is a pretty new product and for the street at least as good as the steel brake, why??? PCCB does NOT provide a shorter braking distance because of the facts mentioned above.

so, PCCB is still in it's first generation but the new GT2 (MY 2004) already has an overworked PCCB system (incl. some of the hardware components and some aerodynamical changes to supply the brake swith more air) and it remains to see how good it performs on the track, so again: if you're into serious track racing, going for the regular steel brakes might be a better idea.

btw, the PCCB brake system on the Carrera GT is completely different to that of the 996 Models with the PCCB system installed:
the diameter of the disc is greater than that of the smaller system on the 996 models. (380mm vs 350mm), thereby increasing its efficiency. the cooling system of the brakes is much more advanced and channels significantly more cooling air to the brakes than on the 996 models and it has specially developed brake pads.






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