Swap out PCCB for track days?
05-12-2006, 07:15 PM
#16
I have a 987S with PCCB and I have decided to leave the ceramic discs in place for DE events. So far, so good, but it's still early. By the way, at least with the Gen2 rotors, the thickness doesn't seem to indicate wear reliably. The dealer mechanic showed me several dime-sized regions of the Gen2 discs near the outer edge of the frictional surfaces which are composed of a different carbon fiber weave (actually, they're Gen1 weaves incorporated into the Gen2 discs). Apparently, as the discs wear, the difference in appearance between the two materials becomes more pronounced, indicating the wear level.
-Dan
-Dan
05-12-2006, 07:44 PM
#17
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Do we know anyone who could fade the steel rotors? The PCCB's seem like all cost and no benefit. The savings in rotational mass and it's relationship to performance is trivial for non-competition track events. There is no improvement in stopping distance. So what do you get? Longer wear is irrelevant, because no amount of time is going to bring the PCCB's within the cost of 5 complete sets of steel rotors. I have yet to see the PCCB driver who expects to keep his car for 250,000 street miles.
In my opinion, if you are going to track, take off the PCCB's and leave them in a box til you stop tracking or sell the car. All you need is one failed rotor with warranty denial to get ticked off permanently. AS
In my opinion, if you are going to track, take off the PCCB's and leave them in a box til you stop tracking or sell the car. All you need is one failed rotor with warranty denial to get ticked off permanently. AS
05-12-2006, 08:18 PM
#18
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Originally Posted by Alexander Stemer
Do we know anyone who could fade the steel rotors?
Even a light weight race car can experience brake fade given the right track.
That said, the ceramic rotors are without a doubt a performance advantage on most tracks. Often times during a session, steel rotor drivers need to adjust their brake points to compensate for the fade they encounter.
Cosmetically they are nice too because the whole setup produces about 5% of the amount of brake dust as conventional units.
I personally do not have ceramic brakes, but I thoroughly wish that I did.
05-12-2006, 11:14 PM
#19
Race Director
Originally Posted by Edgy01
Great minds think alike. Prior to ordering the PCCB for my C2S Cab I did the same thing. The PCCB pads were $100 more than the non-PCCB brakes,--roughly $350 for the PCCB pads.
Over time the rotor costs should drop. Was talking to a 996 TT guy who dropped by my dealership when I was in there and he showed me his PCCBs on his turbo,--14,000 miles on them and absolutely no wear evident at all. I think they finally fixed the problem,--unfortunately at the expense of the first gen. buyers. Personally,--I think Porsche owes them big time.
Dan
Over time the rotor costs should drop. Was talking to a 996 TT guy who dropped by my dealership when I was in there and he showed me his PCCBs on his turbo,--14,000 miles on them and absolutely no wear evident at all. I think they finally fixed the problem,--unfortunately at the expense of the first gen. buyers. Personally,--I think Porsche owes them big time.
Dan
05-12-2006, 11:34 PM
#20
Alexander-
I have had two instances of brake fade (on my '01 986S with steel rotors, of course), not to mention several examples of the pedal getting pretty soft. This was from an engine only capable of 250 BHP of power output. However, since I'm not racing, per se, one could easily argue that, for the money, I'd be much better off driving half a lap at a reduced speed. I personally did not buy the PCCB so I could avoid those rare brake-cooling moments, though. And as far as brake dust is concerned, I can honestly say that there is less than with steel rotors, but more than enough to discolor the wheels after a week or so of street driving (LEGAL street driving, though with aggressive cornering and braking, mind you).
When the ceramic rotors fail and need to be replaced (they are as likely to need replacing because of damage from rocks as they are from wearing out, according to the dealer's mechanic), they will be costly to replace. However, I am thoroughly enamored by the technology involved here, so when they finally fail, I will bite the bullet and replace them with the same. I work for my money, but I enjoy knowing that this technology is pushing the limits of engineering. Could I drive a Toyota? Of course! Would it be a hell of a lot cheaper? Yup. Faster? Well, the old Supra Turbo was pretty quick on its feet. Hell, my old MR2 could corner pretty well. I bet a few thousand dollars in mods to that would make it even quicker than my stock 987S. However, I just enjoy the technology and engineering that has gone into this car, and the PCCB and PASM are just two examples of how science has managed to push the envelope.
I'm not rich (no trust fund or Wall Street shenanigans in my life), but the PCCB concept and performance was worth the steep price to me given my fascination with the technology. Of course, in one sense, it's only money. I mean, if the prices were the same, given the claimed increase in performance and durability, I might expect that many, if not most, people would choose the PCCB option.
Having said that, and if the pedal feel were identical (it's not; the PCCB requires far less effort to achieve the same deceleration) I'm not sure I'd even know what the rotors were made of while I was driving on the road OR the track. Of course, a touchy middle pedal means the stops took a lot of work to get smooth, especially when heel-toe downshifting into turns, but that's the joy of learning a new car.
With either brake material, you've got some of the best hardware you can put on a car.
-Dan
I have had two instances of brake fade (on my '01 986S with steel rotors, of course), not to mention several examples of the pedal getting pretty soft. This was from an engine only capable of 250 BHP of power output. However, since I'm not racing, per se, one could easily argue that, for the money, I'd be much better off driving half a lap at a reduced speed. I personally did not buy the PCCB so I could avoid those rare brake-cooling moments, though. And as far as brake dust is concerned, I can honestly say that there is less than with steel rotors, but more than enough to discolor the wheels after a week or so of street driving (LEGAL street driving, though with aggressive cornering and braking, mind you).
When the ceramic rotors fail and need to be replaced (they are as likely to need replacing because of damage from rocks as they are from wearing out, according to the dealer's mechanic), they will be costly to replace. However, I am thoroughly enamored by the technology involved here, so when they finally fail, I will bite the bullet and replace them with the same. I work for my money, but I enjoy knowing that this technology is pushing the limits of engineering. Could I drive a Toyota? Of course! Would it be a hell of a lot cheaper? Yup. Faster? Well, the old Supra Turbo was pretty quick on its feet. Hell, my old MR2 could corner pretty well. I bet a few thousand dollars in mods to that would make it even quicker than my stock 987S. However, I just enjoy the technology and engineering that has gone into this car, and the PCCB and PASM are just two examples of how science has managed to push the envelope.
I'm not rich (no trust fund or Wall Street shenanigans in my life), but the PCCB concept and performance was worth the steep price to me given my fascination with the technology. Of course, in one sense, it's only money. I mean, if the prices were the same, given the claimed increase in performance and durability, I might expect that many, if not most, people would choose the PCCB option.
Having said that, and if the pedal feel were identical (it's not; the PCCB requires far less effort to achieve the same deceleration) I'm not sure I'd even know what the rotors were made of while I was driving on the road OR the track. Of course, a touchy middle pedal means the stops took a lot of work to get smooth, especially when heel-toe downshifting into turns, but that's the joy of learning a new car.
With either brake material, you've got some of the best hardware you can put on a car.
-Dan
05-12-2006, 11:37 PM
#21
Race Director
[QUOTE=wambo]Alexander-
I have had two instances of brake fade (on my '01 986S with steel rotors, of course), not to mention several examples of the pedal getting pretty soft./QUOTE]
Have you tried better quality brake fluid?
I have had two instances of brake fade (on my '01 986S with steel rotors, of course), not to mention several examples of the pedal getting pretty soft./QUOTE]
Have you tried better quality brake fluid?
05-12-2006, 11:42 PM
#22
Three Wheelin'
Originally Posted by wambo
I'm not rich (no trust fund or Wall Street shenanigans in my life), but the PCCB concept and performance was worth the steep price to me given my fascination with the technology.
all i've heard from experienced performance enthusiasts is that they
would love to have the pccb's as long as they didn't have to pay for them.
05-12-2006, 11:53 PM
#23
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FWIW
PDE ran their 997S cars for a full year with PCCB at Barber.
Anyone who has driven there knows that it is a track with alot of hard braking and alot of trail braking to keep a bit of weight on thhe nose.
The PDE cars are driven by alot of different folks, some know track braking, some have no clue.
The cars loged between 4 to 8000 mi for the year on the track.
This was a pretty good test bed for the durability of PCCB.
The result:
NO rotor problems or issues...Pad replacements only.
PDE ran their 997S cars for a full year with PCCB at Barber.
Anyone who has driven there knows that it is a track with alot of hard braking and alot of trail braking to keep a bit of weight on thhe nose.
The PDE cars are driven by alot of different folks, some know track braking, some have no clue.
The cars loged between 4 to 8000 mi for the year on the track.
This was a pretty good test bed for the durability of PCCB.
The result:
NO rotor problems or issues...Pad replacements only.
05-12-2006, 11:57 PM
#24
Icon-
I spent some time (granted, it was after receiving the car) researching the difference between Gen1 and Gen2 PCCB. I finally found a mechanic (who works for my dealer, no less!) who knew quite a bit about the brakes. (He seems to know quite a bit about my car generally, as he recently replaced the engine, clutch and flywheel on my 06 987S - but that's another story!)
The Gen1 rotors had very large vents in them. Under heavy pressure, there was apparently enough flex in the rotor material to cause the surface of the rotors to wear unevenly. What was once a smooth surface now became washboard-shaped. This lead to uneven heating, further distortion, and as a result, a very abrasive surface. The pads were rapidly chewed up, causing them to damage further the rotors. Apparently, in their testing, the Porsche engineers must have managed their brake pedal pressure differently than the general public.
Once Porsche figured out why the Gen1 rotors were failing, they apparently changed three critical features of the design:
1. They made the vents smaller, thus increasing the internal rigidity of the rotor.
2. They moved the cross-drilled holes so that they dissipated force more uniformly. They're no longer in uniform arcs but now are more random in appearance.
3. They changed the carbon fiber weave pattern.
These changes allegedly addressed the rotor surface flexion problem. Of course, only time will tell for sure, but then that's the excitement in leading edge technology. I'm sure plenty of people complained about the high cost and early failures encountered with, say, fuel injection. However, as the science improved and the miles accrued, the technology was perfected. Perhaps I, too, am too early to the party, but we'll know in a few years. Either way, I can assure you that I won't have any trophies to show, since the car is simply a glorious, overpriced toy when it comes down to it.
-W
I spent some time (granted, it was after receiving the car) researching the difference between Gen1 and Gen2 PCCB. I finally found a mechanic (who works for my dealer, no less!) who knew quite a bit about the brakes. (He seems to know quite a bit about my car generally, as he recently replaced the engine, clutch and flywheel on my 06 987S - but that's another story!)
The Gen1 rotors had very large vents in them. Under heavy pressure, there was apparently enough flex in the rotor material to cause the surface of the rotors to wear unevenly. What was once a smooth surface now became washboard-shaped. This lead to uneven heating, further distortion, and as a result, a very abrasive surface. The pads were rapidly chewed up, causing them to damage further the rotors. Apparently, in their testing, the Porsche engineers must have managed their brake pedal pressure differently than the general public.
Once Porsche figured out why the Gen1 rotors were failing, they apparently changed three critical features of the design:
1. They made the vents smaller, thus increasing the internal rigidity of the rotor.
2. They moved the cross-drilled holes so that they dissipated force more uniformly. They're no longer in uniform arcs but now are more random in appearance.
3. They changed the carbon fiber weave pattern.
These changes allegedly addressed the rotor surface flexion problem. Of course, only time will tell for sure, but then that's the excitement in leading edge technology. I'm sure plenty of people complained about the high cost and early failures encountered with, say, fuel injection. However, as the science improved and the miles accrued, the technology was perfected. Perhaps I, too, am too early to the party, but we'll know in a few years. Either way, I can assure you that I won't have any trophies to show, since the car is simply a glorious, overpriced toy when it comes down to it.
-W
05-13-2006, 12:31 AM
#25
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Gen 2 PCCB
Three thousand fibers were previously the new generation has 400,000!
While the 20 air outlets in the first generation are oblong, the new ones are square. And there are twice as many outlets now as before. The perforation pattern on the braking surface has been
changed as well. It used to be regular. Not it's more random.
Entirely new cooling channel geometry. It allows the cooling air to enter with a minimum of friction and accelerates it to a high speed as it exits. The brake disk becomes a turbine- to maximize airflow at any engine speed. At 200 km/h, an air flow of about 250 liters per second is conducted efficiently through these channels along the internal surface of the disk.
The result: The new design has improved efficiency by 20 percent.
Three thousand fibers were previously the new generation has 400,000!
While the 20 air outlets in the first generation are oblong, the new ones are square. And there are twice as many outlets now as before. The perforation pattern on the braking surface has been
changed as well. It used to be regular. Not it's more random.
Entirely new cooling channel geometry. It allows the cooling air to enter with a minimum of friction and accelerates it to a high speed as it exits. The brake disk becomes a turbine- to maximize airflow at any engine speed. At 200 km/h, an air flow of about 250 liters per second is conducted efficiently through these channels along the internal surface of the disk.
The result: The new design has improved efficiency by 20 percent.
05-13-2006, 01:04 AM
#27
Wambo,
I enjoyed and appreciated your thoughtful and insightful replies. You should join Rennlist. Your relatively minor financial contribution will help keep this exchange in good health for all readers, myself included.
I've been a member for a while now and can tell you, it's among the best forums on the net.
Thank you,
MC
I enjoyed and appreciated your thoughtful and insightful replies. You should join Rennlist. Your relatively minor financial contribution will help keep this exchange in good health for all readers, myself included.
I've been a member for a while now and can tell you, it's among the best forums on the net.
Thank you,
MC
05-13-2006, 09:55 AM
#28
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2nd Gen PCCB
I too have the 2nd gen PCCB's on my new 997 C2S and prior to ordering also heard about the resolution from 1st to 2nd gen PCCB's and how well they now stand up to wear and lack of failure.
No idea how long these are going to last, but may look into "track" pads if I run it on the track. As for now, it's street only.
Deanski
No idea how long these are going to last, but may look into "track" pads if I run it on the track. As for now, it's street only.
Deanski
05-13-2006, 01:08 PM
#29
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It's a good idea to check the pads and if they're almost half way gone, replace them. My turbo S came with PCCB Gen II's and I tracked the car a few times. No wear and they impressed me so much that I ordered them on my 997 Gt3.
