View Poll Results: PCCB or Steel Brakes on your 991 GT3?
PCCBs, the car is for street driving only.
150
22.76%
PCCBs, and I'll track it that way too.
148
22.46%
PCCB, but buying steel rotors or system for track.
44
6.68%
Steel brakes, it's the way I roll.
317
48.10%
Voters: 659. You may not vote on this poll
PCCB or Steel on your 991 GT3?
05-09-2019, 06:00 PM
#287
Race Director
05-09-2019, 08:23 PM
#288
Rennlist Member
A question to “track rats”.
For how long would PCCB rotors last if a car is used for track days?
My steel rotors were typically dead after 4-5 full track days. Typically the vibration was the reason to change for a new set of the rotors.
I have two sets: OEM steel brakes and OEM PCCB. I upgraded my steel set for PCCB with the idea to use PCCB fir street and stell for track days. But I begin to think that maybe I use PCCB for track days also given that:
1) you can find good offeres on ebay like this, where you can buy a complete set of new PCCB rotors and pads for $10K: https://www.ebay.de/itm/NEU-Porsche-...-/303054395558
2) if the PCCB rotors can last at least 25 full track days. “Full track days” is where you push the car really hard all day long with 250 miles per every track day.
I am tired of constant vibrations with steel rotors after track days. That is the reason I have an idea for PCCB for track days.
thanks in advance for sharing your experience!
For how long would PCCB rotors last if a car is used for track days?
My steel rotors were typically dead after 4-5 full track days. Typically the vibration was the reason to change for a new set of the rotors.
I have two sets: OEM steel brakes and OEM PCCB. I upgraded my steel set for PCCB with the idea to use PCCB fir street and stell for track days. But I begin to think that maybe I use PCCB for track days also given that:
1) you can find good offeres on ebay like this, where you can buy a complete set of new PCCB rotors and pads for $10K: https://www.ebay.de/itm/NEU-Porsche-...-/303054395558
2) if the PCCB rotors can last at least 25 full track days. “Full track days” is where you push the car really hard all day long with 250 miles per every track day.
I am tired of constant vibrations with steel rotors after track days. That is the reason I have an idea for PCCB for track days.
thanks in advance for sharing your experience!
If your overheating iron rotors in 4 or 5 days factory PCCB's will be toast in about the same time at 12k plus per axle. Stick with iron.
05-09-2019, 10:10 PM
#289
05-10-2019, 08:11 AM
#290
05-10-2019, 08:23 AM
#291
Race Director
05-10-2019, 12:23 PM
#292
My experience is that using the OEM parts is always more simple. Those are always available, you can intall the parts wherever you want, etc.
The brake pads is another story as Pagid or other high temperature pads are also always avaiable as so many people use them.
05-10-2019, 12:29 PM
#293
05-10-2019, 01:24 PM
#294
Rennlist Member
PCCB wear is very very dependent on driving style and brake usage - lighter usage = they last longer, heavy usage = they last less time - there is _NO_ fixed duration for which they will last, it depends on the track, the driver, and the conditions! If you don't heat them up and use them heavily they last a very very long time, if you do use them heavily they last a much shorter period of time.
they do not magically expire on day 29 - the ONLY way to tell if the rotors are "done" is to measure them with a density meter (wheels off, car in the air, preferably rotors off on a bench).
don't focus on how long they will last - they may last forever
focus on the cost to replace them when it does come time to replace them - if you're comfortable with that cost then PCCB's are great - if you're not comfortable with that cost they I would suggest looking for an alternative. The fact of the matter is how long they last depends on how much you use them, and there is no good answer - but if you track the PCCB's and you do wear them out replacement costs are as follows:
https://rennlist.com/forums/991-gt3-...-watson-2.html
post #45
parts cost (plus shipping) to do a PCCB brake job (no labor) is:
$25,363.03
if you are comfortable with that as a brake job cost then track the PCCB's all you want.
they do not magically expire on day 29 - the ONLY way to tell if the rotors are "done" is to measure them with a density meter (wheels off, car in the air, preferably rotors off on a bench).
don't focus on how long they will last - they may last forever
focus on the cost to replace them when it does come time to replace them - if you're comfortable with that cost then PCCB's are great - if you're not comfortable with that cost they I would suggest looking for an alternative. The fact of the matter is how long they last depends on how much you use them, and there is no good answer - but if you track the PCCB's and you do wear them out replacement costs are as follows:
https://rennlist.com/forums/991-gt3-...-watson-2.html
post #45
parts cost (plus shipping) to do a PCCB brake job (no labor) is:
$25,363.03
if you are comfortable with that as a brake job cost then track the PCCB's all you want.
05-10-2019, 03:40 PM
#295
Race Director
TrakCar and the guys doing the ccb rotors from AutoQuest are using Pagid pads...never heard of any issues getting pads and these rotors last longer than anything and can be refurbished. These guys do like 20-30 days a year on them
05-10-2019, 03:42 PM
#296
Race Director
doubt know about those pads and pccb. I had no issue at Sebring with stock pccb pads over heating...but we will see later this year
05-10-2019, 04:43 PM
#297
Rennlist Member
I don't think PCCB's "overheat" - they just wear out faster - brake fade is not something that they experience - nor do the rotors "warp" - they would break if they did that…high thermal stress just causes them to degrade structurally faster.
I've owned and read a lot about PCCB"s - overheating is NOT a problem I've seen - excessive heat just causes them to wear faster - but from all accounts they remain stunningly functional even in extreme thermal stress conditions - but you end up "vaporizing" carbon elements in the resin mixture which leads to density loss - once a certain density threshold is achieve it's considered prudent to replace the rotors due to loss of structural integrity - the density can be measured by a tool via Porsche Service, and there are published thresholds for acceptable density...
it was explained to me this way: the PCCB rotors are a mix of ceramic, resin, carbon fibers - the carbon fibers behave much like re-bar in concrete - they add structural rigidity to the overall rotors - but the carbon fibers will vaporize/degrade in high thermal conditions (like a fuse burning) - and after you've vaporized enough Cabron Fiber's from your rotor it's not longer structurally sound and needs to be replaced.
\so the wear characteristics of PCCB's are nearly 100% dependent on how hot you get your brakes and how often you get them that hot and how long they stay that way…if the brakes are not thermally stressed then there is no carbon vaporization and therefore little if any rotor wear from a density point of view, and therefore very little need to replace the rotors.
but if you are commonly roasting them and getting them to glow you won't suffer brake fade or effectiveness loss, you're just wearing the rotors at an accelerated rate (via density loss)
this is what makes it sooooo hard to predict PCCB rotor life - and the determination of life requires an expensive sensor and removing the rotors from the wheels for accurate measurements - you can not visually determine if the rotors are worn (other than explicit damage, but that's not what is being discussed here). Also I have tried and can not obtain information about how to purchase a PCCB sensor so I don't have to pay a dealer to measure my rotors…
again it's comes down to your tolerance of cost when the time comes to replace them due to wear, and the ongoing cost to determine _IF_ they have worn (paying a dealer to take the rotors off your car to measure them).
I've owned and read a lot about PCCB"s - overheating is NOT a problem I've seen - excessive heat just causes them to wear faster - but from all accounts they remain stunningly functional even in extreme thermal stress conditions - but you end up "vaporizing" carbon elements in the resin mixture which leads to density loss - once a certain density threshold is achieve it's considered prudent to replace the rotors due to loss of structural integrity - the density can be measured by a tool via Porsche Service, and there are published thresholds for acceptable density...
it was explained to me this way: the PCCB rotors are a mix of ceramic, resin, carbon fibers - the carbon fibers behave much like re-bar in concrete - they add structural rigidity to the overall rotors - but the carbon fibers will vaporize/degrade in high thermal conditions (like a fuse burning) - and after you've vaporized enough Cabron Fiber's from your rotor it's not longer structurally sound and needs to be replaced.
\so the wear characteristics of PCCB's are nearly 100% dependent on how hot you get your brakes and how often you get them that hot and how long they stay that way…if the brakes are not thermally stressed then there is no carbon vaporization and therefore little if any rotor wear from a density point of view, and therefore very little need to replace the rotors.
but if you are commonly roasting them and getting them to glow you won't suffer brake fade or effectiveness loss, you're just wearing the rotors at an accelerated rate (via density loss)
this is what makes it sooooo hard to predict PCCB rotor life - and the determination of life requires an expensive sensor and removing the rotors from the wheels for accurate measurements - you can not visually determine if the rotors are worn (other than explicit damage, but that's not what is being discussed here). Also I have tried and can not obtain information about how to purchase a PCCB sensor so I don't have to pay a dealer to measure my rotors…
again it's comes down to your tolerance of cost when the time comes to replace them due to wear, and the ongoing cost to determine _IF_ they have worn (paying a dealer to take the rotors off your car to measure them).
The following users liked this post:
Captain P (03-10-2023)
05-10-2019, 05:32 PM
#298
Rennlist Member
Originally Posted by daveo4porsche
I don't think PCCB's "overheat" - they just wear out faster - brake fade is not something that they experience - nor do the rotors "warp" - they would break if they did that…high thermal stress just causes them to degrade structurally faster.
I've owned and read a lot about PCCB"s - overheating is NOT a problem I've seen - excessive heat just causes them to wear faster - but from all accounts they remain stunningly functional even in extreme thermal stress conditions - but you end up "vaporizing" carbon elements in the resin mixture which leads to density loss - once a certain density threshold is achieve it's considered prudent to replace the rotors due to loss of structural integrity - the density can be measured by a tool via Porsche Service, and there are published thresholds for acceptable density...
it was explained to me this way: the PCCB rotors are a mix of ceramic, resin, carbon fibers - the carbon fibers behave much like re-bar in concrete - they add structural rigidity to the overall rotors - but the carbon fibers will vaporize/degrade in high thermal conditions (like a fuse burning) - and after you've vaporized enough Cabron Fiber's from your rotor it's not longer structurally sound and needs to be replaced.
\so the wear characteristics of PCCB's are nearly 100% dependent on how hot you get your brakes and how often you get them that hot and how long they stay that way…if the brakes are not thermally stressed then there is no carbon vaporization and therefore little if any rotor wear from a density point of view, and therefore very little need to replace the rotors.
but if you are commonly roasting them and getting them to glow you won't suffer brake fade or effectiveness loss, you're just wearing the rotors at an accelerated rate (via density loss)
this is what makes it sooooo hard to predict PCCB rotor life - and the determination of life requires an expensive sensor and removing the rotors from the wheels for accurate measurements - you can not visually determine if the rotors are worn (other than explicit damage, but that's not what is being discussed here). Also I have tried and can not obtain information about how to purchase a PCCB sensor so I don't have to pay a dealer to measure my rotors…
again it's comes down to your tolerance of cost when the time comes to replace them due to wear, and the ongoing cost to determine _IF_ they have worn (paying a dealer to take the rotors off your car to measure them).
I've owned and read a lot about PCCB"s - overheating is NOT a problem I've seen - excessive heat just causes them to wear faster - but from all accounts they remain stunningly functional even in extreme thermal stress conditions - but you end up "vaporizing" carbon elements in the resin mixture which leads to density loss - once a certain density threshold is achieve it's considered prudent to replace the rotors due to loss of structural integrity - the density can be measured by a tool via Porsche Service, and there are published thresholds for acceptable density...
it was explained to me this way: the PCCB rotors are a mix of ceramic, resin, carbon fibers - the carbon fibers behave much like re-bar in concrete - they add structural rigidity to the overall rotors - but the carbon fibers will vaporize/degrade in high thermal conditions (like a fuse burning) - and after you've vaporized enough Cabron Fiber's from your rotor it's not longer structurally sound and needs to be replaced.
\so the wear characteristics of PCCB's are nearly 100% dependent on how hot you get your brakes and how often you get them that hot and how long they stay that way…if the brakes are not thermally stressed then there is no carbon vaporization and therefore little if any rotor wear from a density point of view, and therefore very little need to replace the rotors.
but if you are commonly roasting them and getting them to glow you won't suffer brake fade or effectiveness loss, you're just wearing the rotors at an accelerated rate (via density loss)
this is what makes it sooooo hard to predict PCCB rotor life - and the determination of life requires an expensive sensor and removing the rotors from the wheels for accurate measurements - you can not visually determine if the rotors are worn (other than explicit damage, but that's not what is being discussed here). Also I have tried and can not obtain information about how to purchase a PCCB sensor so I don't have to pay a dealer to measure my rotors…
again it's comes down to your tolerance of cost when the time comes to replace them due to wear, and the ongoing cost to determine _IF_ they have worn (paying a dealer to take the rotors off your car to measure them).
If you are looking for the tool, it is the Carboteq tool made by Proceq. Can be measured on the car or off (more accurate) at three points for each disc. The operating density range is stamped on the hat in these locations, the tool records the measurement for each to track wear. Alternative is removing the discs, thoroughly cleaning them and then weighing each. Not practical for most. The tool can be bought for around $5k I think if you really want one.
05-10-2019, 05:51 PM
#299
Rennlist Member
thanks @signes I appreciate the clarifications
I've attempted to buy the tool and have never been able to complete a purchase- do you know of any cases where the tool has been successfully purchased by an individual or a small/medium mechanic's shop? We have been trying for years and never able to be successful.
I've attempted to buy the tool and have never been able to complete a purchase- do you know of any cases where the tool has been successfully purchased by an individual or a small/medium mechanic's shop? We have been trying for years and never able to be successful.
05-10-2019, 05:53 PM
#300
Rennlist Member