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Amateur drivers tend to be harder on brakes than more experienced drivers.
Amateur drivers tend to trigger traction control -- either intentionally or inadvertently -- more than advanced drivers, which is killer on the rear brakes.
Very telling little article. I notice that it does NOT reference any official Porsche statement, but the verbal suggestion of one race tech. Then it mentions Brembo options, stating that their carbon ceramic setup costs four times more than their steel setup, but also that it lasts four times longer, which would seem to be a wash cost-wise.
Regardless, I've decided to run my PCCBs through until the end and find out for myself. If my highest priority was the lowest brake cost per track mile, I would have kept running my Exige.
Amateur drivers tend to be harder on brakes than more experienced drivers.
Amateur drivers tend to trigger traction control -- either intentionally or inadvertently -- more than advanced drivers, which is killer on the rear brakes.
That's for sure, years back I went to adjust the ***** on the top of the rear JRZ coilovers I had on a Cayman R (steel brakes) after a session and burn't the crap out of my fingers! The rears on my PCCB GT4 would sit there after a session, smoking / heat waves pouring off them. In spite of that the rear rotors were only 15% down when I traded the GT4 in after 2 years of tracking. There was a long thread about PCCBs a couple of years ago and IIRC someone posted that all of the GT cars at PEC were running PCCBs and they were not wearing the rotors out abnormally fast according to the Porsche employee who ran the place. I guess I'm a little tired of companies selling brake parts spreading misinformation that doesn't seem to be based on reality.
To answer above comments about brake wear, yes 3 weekends on CCM's is excessive, yes a Corvette is not a GT3/GT4 etc. We try to keep out posts knowledgeable with hands on experience.
As far as our customers with Porsche's and CCM's I'd say a majority of heavily tracked cars we service opt for a Girodisc steel conversion with a Pagid or Ferodo race pad. Most customers are surprised when they learn a "conversion" doesn't involve jenky caliper brackets etc. When you do a Girodisc steel conversion you simply remove your CCM rotors (and CCM pads) and install the Giro steel rotors and new pads. That's it, no aftermarket bracketry is involved etc.
When you do a conversion to steel rotors on a CCM 991 your brake pad height or "swept area" (referred to by brake engineers as the annulus) is smaller. This is for a few reasons. Reason 1 is that the CCM pads/rotors must have a larger annulus to provide the same braking capability as their steel counterparts. Reason 2 the steel conversion rotors have a smaller swept area/annulus is to save weight, since you do not need the same sweep area on the steel rotor it does not make sense to have the heavier steel rotor the same size.
^ Front Iron brake pad for 991/992/GT4. Note "annulus" of 80mm ^ Rear CCM brake pad for 991/992/GT4. Note "annulus" of 88mm
We try to keep out posts knowledgeable with hands on experience.
If you're serious about that statement then I would suggest providing somebody's actual hands on Porsche experience.
I drank the Kool-Aid 3 years ago with the GT4 and put on Giro's/Ferodo pads towards the end of my ownership because I was sure I was destroying the PCCB rotors (because of threads like this). It was at that point Porsche of Monterey tested the PCCB rotors I took off and I realized I was worrying about nothing. There went $5K for a new system I didn't need and that I really was never happy with. My "hands on" experience FWIW.
To answer above comments about brake wear, yes 3 weekends on CCM's is excessive, yes a Corvette is not a GT3/GT4 etc. We try to keep out posts knowledgeable with hands on experience.
As far as our customers with Porsche's and CCM's I'd say a majority of heavily tracked cars we service opt for a Girodisc steel conversion with a Pagid or Ferodo race pad. Most customers are surprised when they learn a "conversion" doesn't involve jenky caliper brackets etc. When you do a Girodisc steel conversion you simply remove your CCM rotors (and CCM pads) and install the Giro steel rotors and new pads. That's it, no aftermarket bracketry is involved etc.
When you do a conversion to steel rotors on a CCM 991 your brake pad height or "swept area" (referred to by brake engineers as the annulus) is smaller. This is for a few reasons. Reason 1 is that the CCM pads/rotors must have a larger annulus to provide the same braking capability as their steel counterparts. Reason 2 the steel conversion rotors have a smaller swept area/annulus is to save weight, since you do not need the same sweep area on the steel rotor it does not make sense to have the heavier steel rotor the same size.
^ Front Iron brake pad for 991/992/GT4. Note "annulus" of 80mm ^ Rear CCM brake pad for 991/992/GT4. Note "annulus" of 88mm
Maybe the info still holds true, and maybe it's just a nomenclature thing and I'm being semantic, but CCM rotors are not the same thing as the CCBs that come on Porsches. Are you sure you're talking apples-to-apples here? Corvettes come with CCM. Porsche use CCB. And the rotors on the 997 gen and 991+ cars are different.
Last edited by FourT6and2; 01-27-2022 at 02:54 PM.
As I've said before, the Gen IV PCCBs on the 991 generation is nothing like the Gen III PCCBs on the 997 generation, which is what just about every one on RL base their opinions about PCCBs and track use on.
TL;DR. Gen III =/= Gen IV PCCBs so use your 991 GT3/RS PCCBs.
Maybe the info still holds true, and maybe it's just a nomenclature thing and I'm being semantic, but CCM rotors are not the same thing as the CCBs that come on Porsches. Are you sure you're talking apples-to-apples here? Corvettes come with CCM. Porsche use CCB. And the rotors on the 997 gen and 991+ cars are different.
I think what amateurs do on track is tentatively hold the brakes 'lightly' for long distances leading up to turn in. This leaves very little time for the brakes to cool and generates excessive heat. It will prematurely destroy any setup when done often enough. They will almost be coasting after an early Vmax but with light pedal pressure waiting to apply more as the corner approaches.
CCB = carbon ceramic brake = A floating brake disc made by a core of ceramic material reinforced with carbon fiber and by an additional ceramic layer on both friction surfaces.
CCM = carbon ceramic matrix = A floating brake disc composed of carbon fiber in ceramic matrix.
Which brake rotor design are you actually talking about here? Because you mentioned Corvette earlier as an example. Vettes use CCM. Porsche uses CCB.
Last edited by FourT6and2; 01-27-2022 at 10:40 PM.
I’ve been following this thread closely as I’ve got my first track session coming up next weekend. One good option mentioned above was to use up the PCCB’s and then replace with giro disc after as needed rather than purchase a new set of PCCB’s. I might go that route in the end and find out for myself how long these PCCB’s last.
Okay, some hard data on PCCB and track use. These are numbers off of a 2016 GT3. Approximately 70 track days, most by the head PCA instructor here (which I actually think means he isn't super hard on brakes, he's a really efficient driver and very talented). He'd gone through two sets of pads before I bought the car from him, the car was on the third set of stock pads. And by "gone through" I mean running them until the wear warning light came on. Car has 23k miles, 60 days by him and 10 track days by me when these came off. We took three off because I had three replacement rotors to swap on. Front left is getting there but still within spec according to the dealership. I'd expect front right to be similar. Interestingly there is more wear on the left than the right, we have mostly counterclockwise tracks here, I'm wondering if it is related to that.
Okay, some hard data on PCCB and track use. These are numbers off of a 2016 GT3. Approximately 70 track days, most by the head PCA instructor here (which I actually think means he isn't super hard on brakes, he's a really efficient driver and very talented). He'd gone through two sets of pads before I bought the car from him, the car was on the third set of stock pads. And by "gone through" I mean running them until the wear warning light came on. Car has 23k miles, 60 days by him and 10 track days by me when these came off. We took three off because I had three replacement rotors to swap on. Front left is getting there but still within spec according to the dealership. I'd expect front right to be similar. Interestingly there is more wear on the left than the right, we have mostly counterclockwise tracks here, I'm wondering if it is related to that.
Hmm, counter-clockwise would put more load on right side of car (I'd expect the right front pads to be more worn than left). I'm not sure if it applies to PCCB rotors, but on Iron rotors and pads the wear starts slowly and accelerates as you get closer to gone. So, when you see something like 28% thickness left on pads and rotors, you actually have far less on a time basis (or number of track days left).
Hmm, counter-clockwise would put more load on right side of car (I'd expect the right front pads to be more worn than left). I'm not sure if it applies to PCCB rotors, but on Iron rotors and pads the wear starts slowly and accelerates as you get closer to gone. So, when you see something like 28% thickness left on pads and rotors, you actually have far less on a time basis (or number of track days left).
Yeah, this isn't thickness, it is carbon content of the rotors. So, it isn't down to 28% of the thickness of the rotor, it is 28% of the carbon content, and only in one of the three spots on that rotor.
Okay, some hard data on PCCB and track use. These are numbers off of a 2016 GT3. Approximately 70 track days, most by the head PCA instructor here (which I actually think means he isn't super hard on brakes, he's a really efficient driver and very talented). He'd gone through two sets of pads before I bought the car from him, the car was on the third set of stock pads. And by "gone through" I mean running them until the wear warning light came on. Car has 23k miles, 60 days by him and 10 track days by me when these came off. We took three off because I had three replacement rotors to swap on. Front left is getting there but still within spec according to the dealership. I'd expect front right to be similar. Interestingly there is more wear on the left than the right, we have mostly counterclockwise tracks here, I'm wondering if it is related to that.
What exactly are we looking at there? You measure each rotor in three different spots? At three different times? Can you expound please?
01-27-2022, 02:29 AM
