Catastrophic coolant loss causes spin at Mosport
05-27-2010 | 07:34 PM
#46
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From: S.F Bay Area
thanks for bringing it to the forums attention!
05-27-2010 | 10:40 PM
#49
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From: Florence, SC
That makes more sense....
We had the same thing happen to a 996 (GT3?) recently at a CMP DE, the coolant caused a following 930 to spin off track, killing the instructor.
Those press fittings are bull****...
We had the same thing happen to a 996 (GT3?) recently at a CMP DE, the coolant caused a following 930 to spin off track, killing the instructor.
Those press fittings are bull****...
05-28-2010 | 02:47 AM
#53
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Hey guys, good guesses. I appreciate the difficulty in diagnosing driving through online videos, but wanted to drag this out a bit to raise awareness of a fairly serious, albeit rare, issue on our GT3 engines.
There is an aluminum press fitting that goes into the engine that is held in by nothing more than some loctite/glue. When the engine gets really hot under track use and high temps, the loctite/glue can let go and your rear tires are now covered in super hot coolant. In my case, it was the left fitting that came out which doused the left rear tire.
I was very, very lucky that there was slower traffic because I normally come down the straight at ~230km/h and enter that corner pulling >1g at 160km/h. On the lap when the fitting popped out, I was only at 213km/h down the straight and I had backed out of the throttle really early to give the guy ahead some space and was down to a very reasonable 130km/h when the pipe let go.
At the 2:45 mark on this video, this is what a more normal pace is like:
From inside the car, my initial reaction was that the Miata I just passed blew its brakes and hit me, the spin felt so violent and random. Next thought was that I missed the downshift and went into 1st, but that didn't seem plausible. It was only when I smelled the sweet burning coolant that I realized what had happened.
Unfortunately, a car behind me lost control over my coolant and did some minor damage to his car in the tirewall on the entrance to 8. I'm trying to work with one of the shops he's using to bring down the cost of the repair, given the circumstance.
There were a few lessons learned:
1. Change the coolant to water and water wetter when on the track
2. When you spin on the track, get the heck off as fast as you can (I was in problem solving mode instead of survival mode after the spin)
3. Check part no. 997.106.039.90 and 996.106.238.71 for any cracks, wear or movement
Hope this saves someone the scare I went through...
There is an aluminum press fitting that goes into the engine that is held in by nothing more than some loctite/glue. When the engine gets really hot under track use and high temps, the loctite/glue can let go and your rear tires are now covered in super hot coolant. In my case, it was the left fitting that came out which doused the left rear tire.
I was very, very lucky that there was slower traffic because I normally come down the straight at ~230km/h and enter that corner pulling >1g at 160km/h. On the lap when the fitting popped out, I was only at 213km/h down the straight and I had backed out of the throttle really early to give the guy ahead some space and was down to a very reasonable 130km/h when the pipe let go.
At the 2:45 mark on this video, this is what a more normal pace is like:
From inside the car, my initial reaction was that the Miata I just passed blew its brakes and hit me, the spin felt so violent and random. Next thought was that I missed the downshift and went into 1st, but that didn't seem plausible. It was only when I smelled the sweet burning coolant that I realized what had happened.
Unfortunately, a car behind me lost control over my coolant and did some minor damage to his car in the tirewall on the entrance to 8. I'm trying to work with one of the shops he's using to bring down the cost of the repair, given the circumstance.
There were a few lessons learned:
1. Change the coolant to water and water wetter when on the track
2. When you spin on the track, get the heck off as fast as you can (I was in problem solving mode instead of survival mode after the spin)
3. Check part no. 997.106.039.90 and 996.106.238.71 for any cracks, wear or movement
Hope this saves someone the scare I went through...
Glad you're safe!
05-28-2010 | 08:54 AM
#54
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From: Californian
But I have to say, the car control and down shifts were impressive.
Next time, in a spin, bring the wheel back out of full opposite lock so the car doesn't tend to "loop" and of course go two feet in to spare reverse-rotating the engine and stalling -- two feet in is also a good time to be concentrating on the steering wheel position. Once the car is sliding backwards, if the fronts are straight, they won't be a "rudder" to spin the car.
You might also reposition the camera to have a view of the track instead of the rearview mirror. : )
I have been in a similar situation with a faulty Brake Bias - (Only rear Brake with no front) and to be honest due to the speed and severity of the spin, nobody would be able to catch the car or prevent it from spinning in these situations.
As CGT states you can control what happens next, which will ovbiously reduce the possiblilty of a shunt and I felt that you did a good job.
Sounds like it is well worthwhile to get this checked out before going to your next track day.
05-28-2010 | 12:04 PM
#55
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Alex, that's very scary to hear that there are more fittings like this throughout. It's also scary how many people have had this happen, seems a lot of bullets have been dodged. There is no way I'm running on track with coolant anymore. I've replayed what happened over and over again in different scenarios and even on the slow tracks, this failure could have led to serious car damage at best and potentially personal injury at worst.
Alex, what is involved in the fix that your shop does to the engines? I want to talk to my local shop to see if there is a way to reduce the risk of this happening again. Water+waterwetter dumping onto my rear tires when the car is loaded up in turn 4 is not a viable option. Thanks!
Alex, what is involved in the fix that your shop does to the engines? I want to talk to my local shop to see if there is a way to reduce the risk of this happening again. Water+waterwetter dumping onto my rear tires when the car is loaded up in turn 4 is not a viable option. Thanks!
05-28-2010 | 12:25 PM
#56
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From: OH
Can you guys tell us the mixture for H20 and water wetter? Currently, I drive to the track. Is this going to be an issue at all with overheating? I am tracking next weekend at Mid Ohio and would like to make the switch before then.
05-28-2010 | 12:32 PM
#57
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From: Limehouse, ON
^^ Thanks Alex, it would be very helpful if you could summarize the info. More specifically:
- Confirm that only the GT1 block can suffer from these pulled fittings and not the M96/M97
- Confrim that there are indeed 8 of these per engine
- Is there something that can be done in the field or does the motor need to be dropped to fix/secure these couplings. Maybe adding a clamp and lockwire but then, there is certainly a fair amount of pressure involved when these let go so this might not be enough
- Do you think that this is something that can be checked before a track event? i.e. do these things pull out gradually or do they just pop with no warning? It would be nice if we could add an item the the DE tech inspection check list to look at these... but only if a gradual migration could be observed
- Lastly, do you think that these failures are time/mileage related or can they bite you from day one?
The easy solution is the water + wetter substitution but it would be nice to have a more permanent solution and not have to worry about it anymore.
Sorry for all the questions but you are obviously one of the authorities on the matter.
Cheers,
- Confirm that only the GT1 block can suffer from these pulled fittings and not the M96/M97
- Confrim that there are indeed 8 of these per engine
- Is there something that can be done in the field or does the motor need to be dropped to fix/secure these couplings. Maybe adding a clamp and lockwire but then, there is certainly a fair amount of pressure involved when these let go so this might not be enough
- Do you think that this is something that can be checked before a track event? i.e. do these things pull out gradually or do they just pop with no warning? It would be nice if we could add an item the the DE tech inspection check list to look at these... but only if a gradual migration could be observed
- Lastly, do you think that these failures are time/mileage related or can they bite you from day one?
The easy solution is the water + wetter substitution but it would be nice to have a more permanent solution and not have to worry about it anymore.
Sorry for all the questions but you are obviously one of the authorities on the matter.
Cheers,
05-28-2010 | 12:34 PM
#58
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On my last track day I had the same exact coolant press fitting give way. Luckily it happened when I was coming out of a hair pin by a flag station. They promptly black flagged me since a white cloud of smoke was coming out of the rear of the car. Thanks for having the huevos to post this.
There's something wrong the way Porsche designed this press fitting/manifold.
It's held together by epoxy which apparently gave way. BTW, my car has ~ 35k miles on it.
05-28-2010 | 12:43 PM
#59
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From: Canada
if you can give us more specific instruction on how to do it right that will be great. Maybe a group buy of your clamps?
having said that, we still can't prevent the other cars on the track from leaking...
it is sad reading track related posts lately.
05-28-2010 | 01:32 PM
#60
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There seem to be two scenarios... really new cars doing it (glue hasn't set?) or the 5-6+ year old ones that have lived a hard life. I don't know how long Porsche expects the "glue" to last but with heat, age, pressure etc... it's not going to last forever^^ Thanks Alex, it would be very helpful if you could summarize the info. More specifically:
- Confirm that only the GT1 block can suffer from these pulled fittings and not the M96/M97
- Confrim that there are indeed 8 of these per engine
- Is there something that can be done in the field or does the motor need to be dropped to fix/secure these couplings. Maybe adding a clamp and lockwire but then, there is certainly a fair amount of pressure involved when these let go so this might not be enough
- Do you think that this is something that can be checked before a track event? i.e. do these things pull out gradually or do they just pop with no warning? It would be nice if we could add an item the the DE tech inspection check list to look at these... but only if a gradual migration could be observed
- Lastly, do you think that these failures are time/mileage related or can they bite you from day one?
The easy solution is the water + wetter substitution but it would be nice to have a more permanent solution and not have to worry about it anymore.
Sorry for all the questions but you are obviously one of the authorities on the matter.
Cheers,
- Confirm that only the GT1 block can suffer from these pulled fittings and not the M96/M97
- Confrim that there are indeed 8 of these per engine
- Is there something that can be done in the field or does the motor need to be dropped to fix/secure these couplings. Maybe adding a clamp and lockwire but then, there is certainly a fair amount of pressure involved when these let go so this might not be enough
- Do you think that this is something that can be checked before a track event? i.e. do these things pull out gradually or do they just pop with no warning? It would be nice if we could add an item the the DE tech inspection check list to look at these... but only if a gradual migration could be observed
- Lastly, do you think that these failures are time/mileage related or can they bite you from day one?
The easy solution is the water + wetter substitution but it would be nice to have a more permanent solution and not have to worry about it anymore.
Sorry for all the questions but you are obviously one of the authorities on the matter.
Cheers,
1)Only the GT1 has this style of fitting and problem yes.
2)997 GT3 has 6 (I'll show you some pix shortly)
3)Nothing you can really do to. The motor has to come out to fix and reach these bastards.
4)See above but the failures we've seen have had two patterns... Really new cars and it happening very quickly aka glue not setting/curing? The second one is cars with a hard life and a lot of years/miles. Basically that's glue isn't going to hold forever.
Alex, that's very scary to hear that there are more fittings like this throughout. It's also scary how many people have had this happen, seems a lot of bullets have been dodged. There is no way I'm running on track with coolant anymore. I've replayed what happened over and over again in different scenarios and even on the slow tracks, this failure could have led to serious car damage at best and potentially personal injury at worst.
Alex, what is involved in the fix that your shop does to the engines? I want to talk to my local shop to see if there is a way to reduce the risk of this happening again. Water+waterwetter dumping onto my rear tires when the car is loaded up in turn 4 is not a viable option. Thanks!
Alex, what is involved in the fix that your shop does to the engines? I want to talk to my local shop to see if there is a way to reduce the risk of this happening again. Water+waterwetter dumping onto my rear tires when the car is loaded up in turn 4 is not a viable option. Thanks!