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Re: RC - Anymore experiences with the PCCB brakes?
Grant, maybe you want to check "FixedWing"'s experience with the PCCB in our forums.
I will have the chance to drive a C4 S equipped with PCCB but til now, I have no date.
If you track race your car, forget about the PCCB...just a conclusion from what I heard here and there...
I will have the chance to drive a C4 S equipped with PCCB but til now, I have no date.
If you track race your car, forget about the PCCB...just a conclusion from what I heard here and there...
Yes, I saw FixedWing's unfortunate experience - how can
Porsche do that? They offer the PCCB on all of their highest performance models (many that will be tracked). Then, they talk about making PCCB the standard for the new 997. If they are so bad, but they plan to make them more common, I can only conclude the following:
1. Porsche has plans to significantly improve them soon
2. There is going to be a reversal in the plan (back to Steel);or
3. There is going to be a Big Problem!
1. Porsche has plans to significantly improve them soon
2. There is going to be a reversal in the plan (back to Steel);or
3. There is going to be a Big Problem!
Re: Also, if Carbon works so well in F1, why not on P-cars?
The carbon brakes need...temperature. The PCCB is not a carbon brake, the rotors are made from a ceramic compound material including carbon. I'm not sure that the PCCB is bad but I think the development should go on.
BTW: a guy from SGL Carbon told me that the Enzo Ferrari and the Mercedes SLR will have a similar brake: made by Brembo and developed by SGL Carbon/Porsche. Brembo is the third manufacturer in the PCCB development team (Porsche, SGL Carbon, Brembo) as far as I know.
BTW: a guy from SGL Carbon told me that the Enzo Ferrari and the Mercedes SLR will have a similar brake: made by Brembo and developed by SGL Carbon/Porsche. Brembo is the third manufacturer in the PCCB development team (Porsche, SGL Carbon, Brembo) as far as I know.
FixedWing's unfortunate experience
I do believe that they can eventually get ceramic brakes right and when they do they will be an improvement. They just aren't there yet and shouldn't be selling a system which is, in my opinion, dangerous.
I am in the USA now. I dropped my car off at the dealer on Tuesday just before I left Belgium. I was able to demonstrate to the dealer pretty effectively all of the handling, noise and brake problems. I suspect that a lot of it is that my car has now seen 51,000 relatively tough kilometers. This is more than most. So I wonder if I am seeing issues that others will not see until their warranties have expired?
The brakes have got so bad now that they are pulling hard one way or the other when they get warmed up. I suspect that the reason might be that they are grabbing at different rates because the various pads and rotors are heating up at different rates due to the different friction levels. The pads are certainly wearing at different rates. The various surfaces all look quite different.
I have lately found myself frequently bent over examining GT2 brake rotors. I saw one GT2 on Tuesday which had 5,000 km on it. In my opinion, these rotors showed the early stages of the defects my rotors have. A few days previously I saw another GT2 which appeared to have much more wear on the brakes. But in this case the rotors did not show the same defect even though they had much more wear on them. Either the rotors are different or it is a matter of driving style.
My big worry now is that they will keep fixing the problem until the warranty expires and then leave me holding a system which really doesn't work and which I am now responsible for fixing at extravagant cost.
S.
I am in the USA now. I dropped my car off at the dealer on Tuesday just before I left Belgium. I was able to demonstrate to the dealer pretty effectively all of the handling, noise and brake problems. I suspect that a lot of it is that my car has now seen 51,000 relatively tough kilometers. This is more than most. So I wonder if I am seeing issues that others will not see until their warranties have expired?
The brakes have got so bad now that they are pulling hard one way or the other when they get warmed up. I suspect that the reason might be that they are grabbing at different rates because the various pads and rotors are heating up at different rates due to the different friction levels. The pads are certainly wearing at different rates. The various surfaces all look quite different.
I have lately found myself frequently bent over examining GT2 brake rotors. I saw one GT2 on Tuesday which had 5,000 km on it. In my opinion, these rotors showed the early stages of the defects my rotors have. A few days previously I saw another GT2 which appeared to have much more wear on the brakes. But in this case the rotors did not show the same defect even though they had much more wear on them. Either the rotors are different or it is a matter of driving style.
My big worry now is that they will keep fixing the problem until the warranty expires and then leave me holding a system which really doesn't work and which I am now responsible for fixing at extravagant cost.
S.
carbon/carbon
They do work at the track but it is a very special application. They don't work at all when cold (so dangerous until warmed up and not suitable for street use). They also need tremendous amounts of cooling air otherwise they will overheat. Our cars aren't set up for this and would need to be completely redesigned.
S.
S.
Re: FixedWing's unfortunate experience
From my earlier post...
I heard from an insider (a long time Porsche racing customer) here (California) that they are having trouble with the ceramic brakes and that Porsche is replacing them for customers that complain. Replacing them with conventional brakes!
RC's response was "...let me put it this way: I won't deny it. "
I heard from an insider (a long time Porsche racing customer) here (California) that they are having trouble with the ceramic brakes and that Porsche is replacing them for customers that complain. Replacing them with conventional brakes!
RC's response was "...let me put it this way: I won't deny it.
"
Conventional brakes
Hi Loren,
Two things:
1) That's PCNA. They seem to be able to do their own thing mostly. For example, look at the very different warranty on cars sold in N.A. compared to the rest of the world.
2) There is a technical problem. On the GT2 Porsche made a cast iron rotor to fit the hub and callipers. But Porsche has never produced the larger rotor that will fit the Turbo hub with the current callipers. They are different. So if Porsche was to do this then they would need to retrofit everything back to original and not just swap the rotors (might not be a bad idea -- the callipers are heavy and not too impressive either).
I think if they offered to retrofit my brakes to original until they got the ceramics sorted out then I would likely go for it at this point.
S.
Two things:
1) That's PCNA. They seem to be able to do their own thing mostly. For example, look at the very different warranty on cars sold in N.A. compared to the rest of the world.
2) There is a technical problem. On the GT2 Porsche made a cast iron rotor to fit the hub and callipers. But Porsche has never produced the larger rotor that will fit the Turbo hub with the current callipers. They are different. So if Porsche was to do this then they would need to retrofit everything back to original and not just swap the rotors (might not be a bad idea -- the callipers are heavy and not too impressive either).
I think if they offered to retrofit my brakes to original until they got the ceramics sorted out then I would likely go for it at this point.
S.
Re: Conventional brakes
My friend doesn't go through PCNA he goes through Porsche Motorsport. I was speaking of the ceramic brakes you buy through Porsche Motorsports. My point was that if they are having trouble with the "racing version" of the brakes... what are they doing on production versions?
It would appear from your message that BOTH have problems!
It would appear from your message that BOTH have problems!
Re: Ceramic brakes in racing
In theory, ceramic brakes could be used for racing but they would need sufficient cooling air so that they never exceeded their operating temperature. In formula racing this is easier as the teams use the air scoops as a way of cheating on the rules dealing with airflow around the tyres. So these scoops are way too big for the minimum airflow that is needed to cool the brakes. Also, the cars are lighter and so don't need as much braking ability. I have heard of teams working on ceramics for F1 racing but it isn't there yet.
The situation is much more difficult for a sedan. Sedans don't have that same critical need to control the airflow around the tyres. So additional cooling air means additional frontal area and additional drag.
Eventually we will see ceramics on the track though. I'm sure of that.
One of the things that I always wonder is why Porsche doesn't mount the rear brakes inboard? Even my old 1973 Jaguar XJ12 had inboard brakes. With inboard brakes unsprung weight would be dramatically reduced and there would be no need for exotically light brake rotors. Could it be that they are mounted out-board simply for the looks??
S.
The situation is much more difficult for a sedan. Sedans don't have that same critical need to control the airflow around the tyres. So additional cooling air means additional frontal area and additional drag.
Eventually we will see ceramics on the track though. I'm sure of that.
One of the things that I always wonder is why Porsche doesn't mount the rear brakes inboard? Even my old 1973 Jaguar XJ12 had inboard brakes. With inboard brakes unsprung weight would be dramatically reduced and there would be no need for exotically light brake rotors. Could it be that they are mounted out-board simply for the looks??
S.
Re: With inboard brakes, cooling is more difficult, isn't it?
Yes, cooling is an issue that would need to be addressed -- especially since the heat would be a lot closer to the differential and other components. Remember that the vast majority of the braking is done at the front. A lot less heat is being produced at the rear. But still, some sort of dedicated airflow would be needed to cool the brakes.
The front brakes could also easily be inboard on the Turbo and C4S. But now you would have even bigger cooling issues. It could be done and it would dramatically reduce unsprung weight.
The airflow necessary to cool inboard brakes could be tied in very nicely with a ground effects car. :)
S.
The front brakes could also easily be inboard on the Turbo and C4S. But now you would have even bigger cooling issues. It could be done and it would dramatically reduce unsprung weight.
The airflow necessary to cool inboard brakes could be tied in very nicely with a ground effects car. :)
S.
Re: With inboard brakes, cooling is more difficult, isn't it?
I would imagine inboard brakes would create a few additional engineering problems... namely the drivetrain lash in the shafts and the flexibility in the shafts themselves. The shafts and joints would have to be beefed up a lot to be able to handle braking forces, and the joints would have to be designed to have zero backlash, which would be very expensive. Certainly you wouldn't want your brakes coming on some time after you depress the pedal while the backlash is taken up- and torsional flex of the shafts could create some real problems! 
Cheers,
Ken
Cheers,
Ken
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