PCCB P-50 motorsport pads
01-04-2007, 04:58 PM
#16
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Originally Posted by frayed
Assuming for the moment that it's nk's driving technique that is respondible for the majority of the fade he's experienced, this would mean that PCCBs are no more tolerant of hamfisted driving than steels.
Besides you're only as strong as your weakest link. The fade can be the result of either the pads, fluid or rotors failing in some sort of way.
Better pads and fluid may result in little to no fade...just a thought.
01-04-2007, 07:06 PM
#17
Three Wheelin'
Originally Posted by leif997
In a post on the racing section; you asked for info on "how to drive a 911"...its has been my experience w/ students of varying levels that excessive attempts at threshold braking often leads to premature brake wear and early fade. I think that your stock brakes should give you many more days of wear and less fade than you are currently experiencing if you are evaluated by a competent instuctor.
I have gone through a season and a half with the same pads and rotors in my GT2R club race car. I actively seek to lessen my braking where possible and try to conserve momentum as much as possible. It sounds like you are seriously scrubbing off way too much speed and as this ties into your other Racing section post, you would be better served to have someone help diagnose your braking issues. The speed you are seeking is tied to conservation of momentum. After 7 - 8 years on the track as you have described; it is assumed that you have a great working knowledge of "the line" at your home track. Adjusting your brake habits will take much time and practice to get out of your current comfort zone. Please follow up wilth an older model 911 or 914 club race car driver for in depth instruction in this and I will bet you a beer (or 3) that you start to shave serious seconds off of your current lap times and save $$ on consumables as well
I have gone through a season and a half with the same pads and rotors in my GT2R club race car. I actively seek to lessen my braking where possible and try to conserve momentum as much as possible. It sounds like you are seriously scrubbing off way too much speed and as this ties into your other Racing section post, you would be better served to have someone help diagnose your braking issues. The speed you are seeking is tied to conservation of momentum. After 7 - 8 years on the track as you have described; it is assumed that you have a great working knowledge of "the line" at your home track. Adjusting your brake habits will take much time and practice to get out of your current comfort zone. Please follow up wilth an older model 911 or 914 club race car driver for in depth instruction in this and I will bet you a beer (or 3) that you start to shave serious seconds off of your current lap times and save $$ on consumables as well
I agree with you on less braking, it's were I have found my lap times improve.. I have the Steel AP front rotor with the rear PCCB using the Porsche Race Pad P-50's which is a step up from the blacks RS-14 with ZERO problems.
This race pad works great cold, I drive it on the street and it has good linear brake torque, it's also a long lasting pad.
With stock pads and PCCB's my pads cracked at the first event, this was on a small track with very little hard braking...around 85% pad remaining and they were junk.
You can't compare the stock pads to the P-50's...different world.
For my street/track use I will look no further than these pads...I am happy.
01-04-2007, 07:11 PM
#18
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Given NK's experience at Sebring here's another thought...
While I've not driven at Sebring I understand it to be a fairly bumpy track. As such, attempts at threshold braking will inevitably invoke ABS...and perhaps a lot. That can't be good for pads and rotors especially PCCBs.
While I've not driven at Sebring I understand it to be a fairly bumpy track. As such, attempts at threshold braking will inevitably invoke ABS...and perhaps a lot. That can't be good for pads and rotors especially PCCBs.
01-04-2007, 07:58 PM
#19
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Originally Posted by BobbyC
The P-50 pads (green) are quite abrasive on the rotors and will shorten their life. If you're not doing club racing enduros the street pads (black) are quite adequate for even the upper run grp DE participants. Just make sure you have Castrol SRF as brake fluid.
And I wouldn't use the P-50 on the street, especially when cold.
And I wouldn't use the P-50 on the street, especially when cold.
Ahh phock it. In the end, it's all a $8,800 leap of faith the porsche got it right this time.
01-04-2007, 08:35 PM
#20
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Originally Posted by leif997
It sounds like you are seriously scrubbing off way too much speed and as this ties into your other Racing section post, you would be better served to have someone help diagnose your braking issues. The speed you are seeking is tied to conservation of momentum.
01-04-2007, 10:00 PM
#21
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Originally Posted by frayed
Bobby, did you have problems with P50's or have you seen others with issues? On steel brakes, oftentimes a decent track pad can be street driven, like a pagid rs 19. My hope was that the motorsport pad from porsche would be streetable w/o tearing up all that silicon carbide.
Ahh phock it. In the end, it's all a $8,800 leap of faith the porsche got it right this time.
Ahh phock it. In the end, it's all a $8,800 leap of faith the porsche got it right this time.
01-04-2007, 10:24 PM
#22
Three Wheelin'
Originally Posted by BobbyC
Frayed, I haven't used the P-50s but came darn close. Got a set and was about to put 'em on before a DE at Watkins Glen...actually 'was going to drive on them from home to track and back. Luckily I had the chance to have a detailed conversation about these pads with a very knowledgeable tech at Porsche Motorsports. In his words, the Green pads were likely to eat at my rotors and he warned that it would be outright dangerous for street driving as they have little bite when cold. Gottta respect this guy. He's good. There you have it.
As much as you have to respect the Porsche tech...I use these on the street and have had good wear on my rotors with ZERO issues when cold.
To check the cold friction level do a search, you will find that they actualy have more cold grip than the RS-19's.
01-04-2007, 10:32 PM
#23
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No offence to anyone but usually tech's will tell you that race pads such as the RS-14's are dangerous on the street (when cold)...my answer is that's bullocks. On my 996GT3 I had the RS-14's and never had any issues either on the street or the track.
What's up with not being able to use the RS-19/29's with the Gen II PCCB rotors?
What's up with not being able to use the RS-19/29's with the Gen II PCCB rotors?
01-04-2007, 10:39 PM
#24
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Originally Posted by MJSpeed
No offence to anyone but usually tech's will tell you that race pads such as the RS-14's are dangerous on the street (when cold)...my answer is that's bullocks. On my 996GT3 I had the RS-14's and never had any issues either on the street or the track.
What's up with not being able to use the RS-19/29's with the Gen II PCCB rotors?
What's up with not being able to use the RS-19/29's with the Gen II PCCB rotors?
01-04-2007, 10:53 PM
#25
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Thanks for the info Bobby. . . I don't put a lot of stock in local dealer techs on issues like that, which deviate from the manual. However, from motorsport tech, I'd have to give due weight to the advice.
Well, I figger by the time I roast the stock pads, this issue will be better flushed out.
Three other points:
1. Not keen on pads, no matter whether state of art, developed for and on conventional iron rotors to be used on silicon/silicon carbide rotors. Very different animal. . .never thought RS 19/29s were that great of an idea, and don't recall Porsche endorsement of these pads on these very different rotors.
2. Was talking to a race shop that's been prepping 997 cars. Stated that the 997 chassis is so optimized for drag, PAG skimped on airflow to the brakes on the regular 997 all in the name of drag. Reported brake problems. Not sure how accurate any of this is, just passing it along.
3. On the 996 GT3, it seems PAG spec'd a different pad compound than on the non GT 996 cars. If accurate, could there be different compounds on 997 GT3 pccb v. 997 pccb?
Well, I figger by the time I roast the stock pads, this issue will be better flushed out.
Three other points:
1. Not keen on pads, no matter whether state of art, developed for and on conventional iron rotors to be used on silicon/silicon carbide rotors. Very different animal. . .never thought RS 19/29s were that great of an idea, and don't recall Porsche endorsement of these pads on these very different rotors.
2. Was talking to a race shop that's been prepping 997 cars. Stated that the 997 chassis is so optimized for drag, PAG skimped on airflow to the brakes on the regular 997 all in the name of drag. Reported brake problems. Not sure how accurate any of this is, just passing it along.
3. On the 996 GT3, it seems PAG spec'd a different pad compound than on the non GT 996 cars. If accurate, could there be different compounds on 997 GT3 pccb v. 997 pccb?
01-04-2007, 11:02 PM
#26
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Originally Posted by BobbyC
Sure u can use them and some on this forum do. But then the pad material on RS 19 is meant for steel rotors and not ceramics. The PCCB pads have ceramic based compounds.
Silicon/silicon carbide/carbon fiber composite is a totally different animal than a cast iron rotor. Iron based pad technology will not entirely transfer over to ceramic composites in terms of tribological performance.
Yeah I know I sound like a geek but I've spent a good part of my professional career on advanced materials/composite technologies.
01-04-2007, 11:06 PM
#27
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Originally Posted by frayed
Thanks for the info Bobby. . . I don't put a lot of stock in local dealer techs on issues like that, which deviate from the manual. However, from motorsport tech, I'd have to give due weight to the advice.
Well, I figger by the time I roast the stock pads, this issue will be better flushed out.
Three other points:
1. Not keen on pads, no matter whether state of art, developed for and on conventional iron rotors to be used on silicon/silicon carbide rotors. Very different animal. . .never thought RS 19/29s were that great of an idea, and don't recall Porsche endorsement of these pads on these very different rotors.
2. Was talking to a race shop that's been prepping 997 cars. Stated that the 997 chassis is so optimized for drag, PAG skimped on airflow to the brakes on the regular 997 all in the name of drag. Reported brake problems. Not sure how accurate any of this is, just passing it along.
3. On the 996 GT3, it seems PAG spec'd a different pad compound than on the non GT 996 cars. If accurate, could there be different compounds on 997 GT3 pccb v. 997 pccb?
Well, I figger by the time I roast the stock pads, this issue will be better flushed out.
Three other points:
1. Not keen on pads, no matter whether state of art, developed for and on conventional iron rotors to be used on silicon/silicon carbide rotors. Very different animal. . .never thought RS 19/29s were that great of an idea, and don't recall Porsche endorsement of these pads on these very different rotors.
2. Was talking to a race shop that's been prepping 997 cars. Stated that the 997 chassis is so optimized for drag, PAG skimped on airflow to the brakes on the regular 997 all in the name of drag. Reported brake problems. Not sure how accurate any of this is, just passing it along.
3. On the 996 GT3, it seems PAG spec'd a different pad compound than on the non GT 996 cars. If accurate, could there be different compounds on 997 GT3 pccb v. 997 pccb?
01-04-2007, 11:16 PM
#28
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Originally Posted by BobbyC
Sure u can use them and some on this forum do. But then the pad material on RS 19 is meant for steel rotors and not ceramics. The PCCB pads have ceramic based compounds.
Bob mentioned that it was the case with the Gen I's but not to be done with the Gen II's. Could the rotor material/finish have changed that much between the two generations?
01-05-2007, 12:30 AM
#29
Three Wheelin'
Originally Posted by nkhalidi
I can't disagree. The only thing I'd mention is that when I try to carry more speed into a turn, the car tends to understeer. Plow plow plow doesn't feel like the fast way around, and I was making a concerted effort to brake hard, go slow-in fast-out, and take advantage of the 911's rear bias. Always trying to learn.
Yeah, the push issue is well documented. I have found on street cars that if you are going to track them, try and have the front toe set an add'l 1/16 out to give a bit more bite on the turn in. It can make the straights a bit twitchy but the toe changes coupled with a light lift off of the throttle will help to induce a bit of oversteer to counter the push. You will have to learn to rotate your car to minimize the push. I alluded to this in my other post on your"how to drive a 911" topic in the racing section. Have a club racer/tech/speed shop representative trackside with you so that adjustments can be dialed in and then applied for immediate feedback. You're gonna have to experiment; trial and error to find the combinations that suit your needs. Just remember: change only one parameter at a time; else you will not be able to differentiate which changes enable which responses. Keep a note book and record your results/impressions. Use your next 4-5 DE days as test and tune days and really concentrate on one or two sections of the track so as to not overwhelm yourself with the cars' attitude changes as they occur.
01-05-2007, 02:07 AM
#30
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Originally Posted by leif997
Yeah, the push issue is well documented. I have found on street cars that if you are going to track them, try and have the front toe set an add'l 1/16 out to give a bit more bite on the turn in. It can make the straights a bit twitchy but the toe changes coupled with a light lift off of the throttle will help to induce a bit of oversteer to counter the push. You will have to learn to rotate your car to minimize the push. I alluded to this in my other post on your"how to drive a 911" topic in the racing section. Have a club racer/tech/speed shop representative trackside with you so that adjustments can be dialed in and then applied for immediate feedback. You're gonna have to experiment; trial and error to find the combinations that suit your needs. Just remember: change only one parameter at a time; else you will not be able to differentiate which changes enable which responses. Keep a note book and record your results/impressions. Use your next 4-5 DE days as test and tune days and really concentrate on one or two sections of the track so as to not overwhelm yourself with the cars' attitude changes as they occur.