996 Turbo brake system failure during track-day.
#16
Many of the potential obvious causes have been raised here already- it might all pass as unremarkable to me other than the description is very similar to quite a number of cases that I am aware of.Brake failure like this where all the obvious issues here go to a low percentage probability because of absoloutely clear maitainence eliminates or at least puts most of the explanations down to near enough zero. But there was still a unexplained brake failure .The possibility is that it is ABS related in some way is there. Turbos being hard used- track/rally have had exactly this type of failure frequently resulting in plenty of damage. To try and get Porsche to concede anything is well nigh impossible-- worldwide that must have a fair sized file of this type of brake failure.
#17
Burning Brakes
it just doesn't make sense that the brake fluid would boil over after just 5 or 6 laps
My 3700lbs car can lost brake feel within 3 laps. It has motul 600 fluids and came stock with Brembos all around. Doesnt help much.
Sorry to see your situation, but I doubt writting to Porsche Asia is going to help much.
Servicing does no entail to "track prep"
#18
Racer
Thread Starter
Thanks for everyone's input. A couple of pieces of information are due here to clear up some of the assumptions being used.
My brother has been on tracks before and he's participated in Formula Renault events, amongst other performance driving courses. While I do consider him to be a novice in that he isn't a track junkie and is not on the track every single weekend, he isn't a complete newbie and understands the differences in car dynamics on a track and at track speeds, as opposed to during your daily grocery run. That said, I'll caveat by saying that I wasn't there in person, and what truly trasnpired is as much a guessing game for me as it is for any of you.
The Cab has a Tiptronic gearbox (long story, it's predecessor had a manual), so I highly doubt he was stepping on the wrong pedal, and he was downshifting as he was approaching the turn which is why he ran wide when he ran into the armco... the photo should make the point of initial impact relatively obvious (tail started to swing wide as he entered the gravel trap).
The car arrived in '04, but doesn't see much use so it only had about 3,700 miles on the odo. As a result, I was adamant about having the car (and all fluids) serviced on a 6-month basis, as opposed to the regular servicing intervals. The car is only ever serviced by the local Porsche dealer.
Wrong. I'm not even going get into the fact that my initial post said nothing about claiming anything from a financial standpoint. My intention here is to make a case to Porsche Asia to look into this matter and give me the results of a studied analysis as to why the brakes failed (be it due to a systemic failure, boiling of the brake fluid, or any other mechanical reason). Why? One reason: What if this had happened on the return journey from the track on a busy highway? Vehicular density on certain sections of the North-South Highway can be similar to that of I-95 during rush hour on Friday evening (for those of you who have had the pleasure of using the NJ Turnpike). In the worst of situations, the fact that this happened on the track where there was a gravel trap and armco was probably the most favorable.
I really hope this wasn't a reference to English being my second language... It is my first language and I hold a degree in English Literature. Granted I wrote the original post at the *** crack of dawn, and working here can really screw up your syntax, but I am still mildly insulted. As mentioned above, I wasn't at the track when this happened, so the extent of my "forensic record of the fact" is what I heard from those who were there, and what I saw of the Cab post-accident.
Anyway, I did a bit more reading into the general causes of track-related brake failure (StopTech's site has some great whitepapers) and I will concede that several of you may be correct in that this was the result of the brakes a) not being bled, and b) the car not having been track-prepped prior to the event, especially given the car's low mileage.
I will still be writing to Porsche Asia for them to have a good look into this case because I want some peace of mind that this brake failure resulted from the car being overworked, and not because of poor maintenance or any other reason which might open up the possibility of something similar happening on road.
A sincere thanks to everyone who contributed (irrespective of any implicit sarcasm), your comments have been helpful. Additional thanks to SpideyTT and Fongster for adding input relevant to the location. Feel free to continue commenting, and I'll update if I (ever) hear from Porsche Asia.
My brother has been on tracks before and he's participated in Formula Renault events, amongst other performance driving courses. While I do consider him to be a novice in that he isn't a track junkie and is not on the track every single weekend, he isn't a complete newbie and understands the differences in car dynamics on a track and at track speeds, as opposed to during your daily grocery run. That said, I'll caveat by saying that I wasn't there in person, and what truly trasnpired is as much a guessing game for me as it is for any of you.
The Cab has a Tiptronic gearbox (long story, it's predecessor had a manual), so I highly doubt he was stepping on the wrong pedal, and he was downshifting as he was approaching the turn which is why he ran wide when he ran into the armco... the photo should make the point of initial impact relatively obvious (tail started to swing wide as he entered the gravel trap).
The car arrived in '04, but doesn't see much use so it only had about 3,700 miles on the odo. As a result, I was adamant about having the car (and all fluids) serviced on a 6-month basis, as opposed to the regular servicing intervals. The car is only ever serviced by the local Porsche dealer.
You want Porsche to pay for all the damage that occurred to the car as a consequence of track-use brake failure, right?
Most of the description here seems to be a bit vague. I think the words chosen reflect more of an "English as a second language" than a forensic record of the facts.
Anyway, I did a bit more reading into the general causes of track-related brake failure (StopTech's site has some great whitepapers) and I will concede that several of you may be correct in that this was the result of the brakes a) not being bled, and b) the car not having been track-prepped prior to the event, especially given the car's low mileage.
I will still be writing to Porsche Asia for them to have a good look into this case because I want some peace of mind that this brake failure resulted from the car being overworked, and not because of poor maintenance or any other reason which might open up the possibility of something similar happening on road.
A sincere thanks to everyone who contributed (irrespective of any implicit sarcasm), your comments have been helpful. Additional thanks to SpideyTT and Fongster for adding input relevant to the location. Feel free to continue commenting, and I'll update if I (ever) hear from Porsche Asia.
#19
Rennlist Member
Wow there is alot of typing in this post!!! Enjoyable reading. AS you are right now that we know the poster has a "degree in English literature" I take the usage of the word jabbing at the brakes as an accurate description and would have to agree it may not be the best technique at the track although I am no pro driver. (just SCCA racing for fun).
Anyway I push the TT at the track with temps on the track up to 120 ALL DAY and when the fluid does start to go it is not sudden. the pedal starts to feel mushy and initially pumping will help. You have plenty of time to recognize this, cool down and bleed if need be.
I still say that if the car and driver were up to par the thread would not be called TT brake failure but **** I guess I should pay more attention to my pre event preparation before I go ***** to the wall at the track!!! LOL
Anyway I push the TT at the track with temps on the track up to 120 ALL DAY and when the fluid does start to go it is not sudden. the pedal starts to feel mushy and initially pumping will help. You have plenty of time to recognize this, cool down and bleed if need be.
I still say that if the car and driver were up to par the thread would not be called TT brake failure but **** I guess I should pay more attention to my pre event preparation before I go ***** to the wall at the track!!! LOL
#20
Burning Brakes
roadsleeper
if the car had gone off at the turn right by the entry to the pits, I am not suprised. The tight right hander entering the back straight is one which requires a significant amount of heavy braking.
I do highly recommend Castrol SRF fluid. If you ask Weng, Mao or any of the regular track junkies from Porsche Club Singapore/Malaysia. They will tell you the same. Weng can give you the exact details on where you can buy some of those in SIngapore. They are expensive, but significantly worth the difference in price.
if the car had gone off at the turn right by the entry to the pits, I am not suprised. The tight right hander entering the back straight is one which requires a significant amount of heavy braking.
I do highly recommend Castrol SRF fluid. If you ask Weng, Mao or any of the regular track junkies from Porsche Club Singapore/Malaysia. They will tell you the same. Weng can give you the exact details on where you can buy some of those in SIngapore. They are expensive, but significantly worth the difference in price.
#21
Originally Posted by roadsleeper
Thanks for everyone's input. A couple of pieces of information are due here to clear up some of the assumptions being used.
The Cab has a Tiptronic gearbox (long story, it's predecessor had a manual)
I really hope this wasn't a reference to English being my second language... It
The Cab has a Tiptronic gearbox (long story, it's predecessor had a manual)
I really hope this wasn't a reference to English being my second language... It
And a Turbo Tip Cab at the track?
<snip>up your syntax, but I am still mildly insulted.
Anyway, good luck with Porsche Asia. Will you be writing to them in English? : )
#24
Rennlist Member
Does anybody have experience with fluid boiling to the point of absolute brake failure? Will the fluid in the cooled resevoir be at the "full" level, or will the resevoir be low? I'm not referencing a mushy pedal, I'm referencing complete loss of all brakes, unresponsive to pumping. This just seems odd to me, but if it is possible, I definitely want to know that can happen.
Once I was in the pits when a fellow vintage Can Am Lola racer rolled his car into a nice ball, and claimed brake failure at the end of the 1 mile straight. Problem was that finger pressure on the pedal stopped the wheels from turning, even though the car could have fit into a large carton. In the end, the true story was that staying wide, he dropped the outside tires off the outside edge of the pavement trying to take advantage of all the road, and lost control when he came back on while entering the corner. Once you get a couple of tires on grass or gravel, it can feel like the car won't stop. (actually, when you get all 4 off, it feels like the car accelerates).
I'd love to be wrong, but I think this will turn out to be a story told to our poster in an attempt to diffuse responsibility. A nearly new tip cab is a heavy car, but the brakes were essentially new, the total laps were few, the failure was unusually sudden, and the word choice is suspect.
Lots of people forget where on the track they are, and set up for a right tun when a left is coming (even AJ Foyt admitted to that), waiting too long to begin braking, or jamming the brakes on and engaging the anti-lock on a slippery surface are more likely explanations. The latter circumstance feel like stopping a speedboat- it takes a long time.
If there is an explanation that absolves the driver, I would love to hear it. I hope Porsche investigate, and our new Rennlister tells us. AS
Once I was in the pits when a fellow vintage Can Am Lola racer rolled his car into a nice ball, and claimed brake failure at the end of the 1 mile straight. Problem was that finger pressure on the pedal stopped the wheels from turning, even though the car could have fit into a large carton. In the end, the true story was that staying wide, he dropped the outside tires off the outside edge of the pavement trying to take advantage of all the road, and lost control when he came back on while entering the corner. Once you get a couple of tires on grass or gravel, it can feel like the car won't stop. (actually, when you get all 4 off, it feels like the car accelerates).
I'd love to be wrong, but I think this will turn out to be a story told to our poster in an attempt to diffuse responsibility. A nearly new tip cab is a heavy car, but the brakes were essentially new, the total laps were few, the failure was unusually sudden, and the word choice is suspect.
Lots of people forget where on the track they are, and set up for a right tun when a left is coming (even AJ Foyt admitted to that), waiting too long to begin braking, or jamming the brakes on and engaging the anti-lock on a slippery surface are more likely explanations. The latter circumstance feel like stopping a speedboat- it takes a long time.
If there is an explanation that absolves the driver, I would love to hear it. I hope Porsche investigate, and our new Rennlister tells us. AS
#26
Rennlist Member
thanks wross, and as usual AS is right I also have never had myself or other track junkies have brakes completely fail it seems to be a gradual process that should be recognized before a serious incident occurs.
#27
Three Wheelin'
Join Date: Jul 2002
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I have never seen brakes fail to the extent to which your brother's turbo did. I don't blame you for asking for an inquiry as to what happened because, barring driver error, it seems to be a series matter which needs to be resolved. Turbo brakes just don't fail so completely. Anyway, glad that your brother is still in one piece.
Good luck.
Good luck.
#28
Rennlist Member
Originally Posted by tkerrmd
thanks wross, and as usual AS is right I also have never had myself or other track junkies have brakes completely fail it seems to be a gradual process that should be recognized before a serious incident occurs.
#29
Rennlist Member
Roadsleeper - hope that you can get to the bottom of what caused this perceived or real brake failure and share your findings with us. This is relevant to all of us who drive a 996TT.
And please ignore any disparaging remarks about your ability to communicate in English...you're doing just fine. There's always an idiot out there who thinks he knows better!
And please ignore any disparaging remarks about your ability to communicate in English...you're doing just fine. There's always an idiot out there who thinks he knows better!
#30
Rennlist Member
Bobby my point was that I personally I never experienced or heard of someone suffer "gee all of a sudden total brake failure" without ANY symtoms prior to the total failure.