PCCB Wear and PTV?
11-13-2017, 12:26 PM
#16
Rennlist Member
MEASURE ROTORS OFF THE CAR
Excellent results, thanks for sharing!
I love the braking bite "attack" and pressure throughout braking on PCCBs.
Would not want to give that up.
Excellent results, thanks for sharing!
Update!
Went back to the same dealer and asked them to remove the rear rotors and measure them again. The service manager asked me 3 times if I was really sure I wanted to do it and even called the lead tech since they all thought it was a waste of time and I might be a little off in the head. However, after assuring them that if the numbers came back exactly the same I wouldn't freak out and that I would pay the tab either way the took the car....
New numbers!
Rotor---Max----On Car----Off Car----Min---New % Worn
LR-------55-----47.7-------52.5-------42----19.2
LR-------56-----49.0-------53.9-------43----16.2
LR-------53-----45.4-------50.4-------41----20
RR-------57-----49.4-------53.9-------43----22.1
RR-------54-----46.7-------51.0-------41----23.1
RR-------58-----50.6-------54.8-------44----22.9
The good news is there is a massive difference with the rotors off the car and the new readings came out to about 21% worn, less than half as bad as the original reading. If anyone is getting their PCCBs measured, definitely have them pulled off the car and thank you to everyone that suggested it.
I'm not upset that they didn't do this the first time since they didn't actually charge me for the first measurements and they are just looking to make sure the rotors are in spec vs trying to geek out and measure wear rates. However, I do wonder how many owners have had to buy new PCCBs due to misreads. I would be PISSED if I spent $10k on PCCBs cause the tech didn't measure the rotors correctly and tossed a perfectly good set of rotors in the trash.
The rate of wear on the rears is still more than double that of the fronts even with the latest readings. That still concerns me but given the front rotors weren't measured off the car and the voodoo in measuring these things, who knows what the real rate is. I'll check again next year but if the wear rate is linear and I can go 20+ years just replacing a rear set of PCCBs that sounds like a good deal to me.
Went back to the same dealer and asked them to remove the rear rotors and measure them again. The service manager asked me 3 times if I was really sure I wanted to do it and even called the lead tech since they all thought it was a waste of time and I might be a little off in the head. However, after assuring them that if the numbers came back exactly the same I wouldn't freak out and that I would pay the tab either way the took the car....
New numbers!
Rotor---Max----On Car----Off Car----Min---New % Worn
LR-------55-----47.7-------52.5-------42----19.2
LR-------56-----49.0-------53.9-------43----16.2
LR-------53-----45.4-------50.4-------41----20
RR-------57-----49.4-------53.9-------43----22.1
RR-------54-----46.7-------51.0-------41----23.1
RR-------58-----50.6-------54.8-------44----22.9
The good news is there is a massive difference with the rotors off the car and the new readings came out to about 21% worn, less than half as bad as the original reading. If anyone is getting their PCCBs measured, definitely have them pulled off the car and thank you to everyone that suggested it.
I'm not upset that they didn't do this the first time since they didn't actually charge me for the first measurements and they are just looking to make sure the rotors are in spec vs trying to geek out and measure wear rates. However, I do wonder how many owners have had to buy new PCCBs due to misreads. I would be PISSED if I spent $10k on PCCBs cause the tech didn't measure the rotors correctly and tossed a perfectly good set of rotors in the trash.
The rate of wear on the rears is still more than double that of the fronts even with the latest readings. That still concerns me but given the front rotors weren't measured off the car and the voodoo in measuring these things, who knows what the real rate is. I'll check again next year but if the wear rate is linear and I can go 20+ years just replacing a rear set of PCCBs that sounds like a good deal to me.
Would not want to give that up.
07-06-2020, 05:13 AM
#17
Is the stock GT4 PCCB good enough for track and reliable?
Or is better pads and brake fluid required?
Or is better pads and brake fluid required?
07-08-2020, 10:22 PM
#18
Rennlist Member
Update!
Went back to the same dealer and asked them to remove the rear rotors and measure them again. The service manager asked me 3 times if I was really sure I wanted to do it and even called the lead tech since they all thought it was a waste of time and I might be a little off in the head. However, after assuring them that if the numbers came back exactly the same I wouldn't freak out and that I would pay the tab either way the took the car....
New numbers!
Rotor---Max----On Car----Off Car----Min---New % Worn
LR-------55-----47.7-------52.5-------42----19.2
LR-------56-----49.0-------53.9-------43----16.2
LR-------53-----45.4-------50.4-------41----20
RR-------57-----49.4-------53.9-------43----22.1
RR-------54-----46.7-------51.0-------41----23.1
RR-------58-----50.6-------54.8-------44----22.9
The good news is there is a massive difference with the rotors off the car and the new readings came out to about 21% worn, less than half as bad as the original reading. If anyone is getting their PCCBs measured, definitely have them pulled off the car and thank you to everyone that suggested it.
I'm not upset that they didn't do this the first time since they didn't actually charge me for the first measurements and they are just looking to make sure the rotors are in spec vs trying to geek out and measure wear rates. However, I do wonder how many owners have had to buy new PCCBs due to misreads. I would be PISSED if I spent $10k on PCCBs cause the tech didn't measure the rotors correctly and tossed a perfectly good set of rotors in the trash.
The rate of wear on the rears is still more than double that of the fronts even with the latest readings. That still concerns me but given the front rotors weren't measured off the car and the voodoo in measuring these things, who knows what the real rate is. I'll check again next year but if the wear rate is linear and I can go 20+ years just replacing a rear set of PCCBs that sounds like a good deal to me.
Went back to the same dealer and asked them to remove the rear rotors and measure them again. The service manager asked me 3 times if I was really sure I wanted to do it and even called the lead tech since they all thought it was a waste of time and I might be a little off in the head. However, after assuring them that if the numbers came back exactly the same I wouldn't freak out and that I would pay the tab either way the took the car....
New numbers!
Rotor---Max----On Car----Off Car----Min---New % Worn
LR-------55-----47.7-------52.5-------42----19.2
LR-------56-----49.0-------53.9-------43----16.2
LR-------53-----45.4-------50.4-------41----20
RR-------57-----49.4-------53.9-------43----22.1
RR-------54-----46.7-------51.0-------41----23.1
RR-------58-----50.6-------54.8-------44----22.9
The good news is there is a massive difference with the rotors off the car and the new readings came out to about 21% worn, less than half as bad as the original reading. If anyone is getting their PCCBs measured, definitely have them pulled off the car and thank you to everyone that suggested it.
I'm not upset that they didn't do this the first time since they didn't actually charge me for the first measurements and they are just looking to make sure the rotors are in spec vs trying to geek out and measure wear rates. However, I do wonder how many owners have had to buy new PCCBs due to misreads. I would be PISSED if I spent $10k on PCCBs cause the tech didn't measure the rotors correctly and tossed a perfectly good set of rotors in the trash.
The rate of wear on the rears is still more than double that of the fronts even with the latest readings. That still concerns me but given the front rotors weren't measured off the car and the voodoo in measuring these things, who knows what the real rate is. I'll check again next year but if the wear rate is linear and I can go 20+ years just replacing a rear set of PCCBs that sounds like a good deal to me.
I discovered this very scenario a few years back. I recall Alan C. and many others also went through the drill.
Experienced Porsche techs know the on car measurement is not accurate. Your service guys must never see cars that are tracked. There are Porsche publications that recommend the off car procedure if the on car procedure shows substantial wear.
And yes it is the PTV which can't be turned off that increases the wear rate on the rears. That is why most guys that track swap to steels , either AP J hooks or giro disc .
The wear rate is not linear either. The rate of wear seems to speed up after about 20 % .
Cheers
