Porsche service for 2000 GT3 Cup
05-21-2012, 09:53 AM
#1
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Porsche service for 2000 GT3 Cup
Broke a stub axle at VIR yesterday .. trying to get it repaired in the Concord NC area this week. Have an event to go to at Mid Ohio this weekend if I can get it repaired.. Anyone know of a good shop that might be able to do this?
thanks
this is a duplicate post in another forum
thanks
this is a duplicate post in another forum
05-21-2012, 02:25 PM
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thanks .. just decided to move everything back to NJ ... work on it there in my garage with my mechanic and change some other things at the same time..
hate to miss Mid Ohio But
05-27-2012, 11:15 PM
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at the outer end of the half shaft.. inside the ???? and about .5 inch inside the the center lug nut... so the wheel passed me by... took out part of rear fender other than that not bad.. certainly could have happened a few hundred yards later in the up hill S's or even worse turn 10... very lucky.. everything is all apart with a parts list for repair we should be good to good to go in about a week .. thanks for all the advise
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05-29-2012, 02:04 AM
#10
It sounds like there may be some Cup Car owners that may not be aware that many components have scheduled maintenance, with specified replacement or rebuild times, usually measured in track hours. A good race shop with extensive Cup car experience, or Ralph in Parts at PMNA (Porsche Motorsport North America) should be able to help you with the times for particular components on various models of Cup Cars, and how it might apply to how you're using your vehicle.
Some of the items that time out are significant safety items, including hubs, stub axles, many suspension components, drive axles, etc. but even calipers, subframe assemblies, etc. will eventually need replacement. Remember that many of the components in Cup Cars (including stub axles) are different than on street cars, and other components (like drive axles) have very different loads. Few street cars hit the gator teeth in exit curbing regularly, or catch air over big bumps, causing significant strain on wheel and drivetrain components.
Since 2004 when I bought my first Cup car, I've had a budget allocated per hour of runtime, as I have a pretty good idea in advance what I'll need to replace and when, but unexpected things will always come up also. I have a full 'nut and bolt' on the car done (car on lift, under panels removed), no more than every two or three events, and carefully check accessible things like brake rotors and pads at every event, and after every session if they're close to being questionable. I'm racing in a competitive series so I don't want to have any DNF's, but even more important to me is my personal safety and that of the drivers and workers around me. I've seen what can happen when a stub axle or other component breaks at an inopportune time.
I also keep the replaced parts (as long as servicable) in the trailer as spares. Having spares in the trailer is also a great way to make friends at an event :-)
Some of the items that time out are significant safety items, including hubs, stub axles, many suspension components, drive axles, etc. but even calipers, subframe assemblies, etc. will eventually need replacement. Remember that many of the components in Cup Cars (including stub axles) are different than on street cars, and other components (like drive axles) have very different loads. Few street cars hit the gator teeth in exit curbing regularly, or catch air over big bumps, causing significant strain on wheel and drivetrain components.
Since 2004 when I bought my first Cup car, I've had a budget allocated per hour of runtime, as I have a pretty good idea in advance what I'll need to replace and when, but unexpected things will always come up also. I have a full 'nut and bolt' on the car done (car on lift, under panels removed), no more than every two or three events, and carefully check accessible things like brake rotors and pads at every event, and after every session if they're close to being questionable. I'm racing in a competitive series so I don't want to have any DNF's, but even more important to me is my personal safety and that of the drivers and workers around me. I've seen what can happen when a stub axle or other component breaks at an inopportune time.
I also keep the replaced parts (as long as servicable) in the trailer as spares. Having spares in the trailer is also a great way to make friends at an event :-)
05-29-2012, 02:32 AM
#12
Yep, stuff just breaks, but a stub axle with two or three hundred hours on it is (IMHO) tempting fate. I of course have no idea how many hours are on the components that failed in this thread, and when or if they've been replaced.
At least if a gearbox goes because you haven't looked at it in five years, it's maybe a flat-tow and a big bill after the weekend. A stub axle or hub can mean a side trip to the emergency room, as well as an even bigger car repair bill.
Some of the time-out failures can be subtle and difficult to spot in a nut and bolt unless you know exactly what to look for. For example, over time, the subframe mounting surface that holds the eccentric bolt in the rear of a 996 Cups can 'mushroom', from the eccentric being tightened when the lip is not 100% flat against the entire mounting surface, but is slightly touching the edge. Do enough alignments, and the eccentric can be tightened against an angled, versus 90 degree, surface, so isn't completely flat, though it's tight when checked and torqued. Then apply vibration and suspension movement under load, and voila, a rear wheel that's moving around. There are corners at certain tracks for which half an inch of sudden toe out in the outside rear wheel is NOT optimal :-) Once you know what to look for, you can spot this in 10 seconds with a flashlight and a peek under the back of a car.
Others are potential stress cracks etc. that can't be easily checked without part removal and testing (magnaflux or other NDT methods), but by the time you remove some of these parts for testing, you might as well just replace as you're already paying for the part removal and replacement.
At least if a gearbox goes because you haven't looked at it in five years, it's maybe a flat-tow and a big bill after the weekend. A stub axle or hub can mean a side trip to the emergency room, as well as an even bigger car repair bill.
Some of the time-out failures can be subtle and difficult to spot in a nut and bolt unless you know exactly what to look for. For example, over time, the subframe mounting surface that holds the eccentric bolt in the rear of a 996 Cups can 'mushroom', from the eccentric being tightened when the lip is not 100% flat against the entire mounting surface, but is slightly touching the edge. Do enough alignments, and the eccentric can be tightened against an angled, versus 90 degree, surface, so isn't completely flat, though it's tight when checked and torqued. Then apply vibration and suspension movement under load, and voila, a rear wheel that's moving around. There are corners at certain tracks for which half an inch of sudden toe out in the outside rear wheel is NOT optimal :-) Once you know what to look for, you can spot this in 10 seconds with a flashlight and a peek under the back of a car.
Others are potential stress cracks etc. that can't be easily checked without part removal and testing (magnaflux or other NDT methods), but by the time you remove some of these parts for testing, you might as well just replace as you're already paying for the part removal and replacement.
05-29-2012, 10:05 AM
#13
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Scott - the worse & most frustrating part for you is that you knew that this was a maintenance item. You had already bought new ones. Driving down from Canada, they were at the shop in New York ready to go on right after that event.
I was right behind you watching the wheel bouncing across the road off the guard rail wondering if I would dodge it. Guy behind me wasn't so sure and changed his shorts.
Did I ever show the you the video?
You dodged a bullet on that one. Broke in T7 at WGI. A dozen faster places with more load and a less happy result.
I was right behind you watching the wheel bouncing across the road off the guard rail wondering if I would dodge it. Guy behind me wasn't so sure and changed his shorts.
Did I ever show the you the video?
You dodged a bullet on that one. Broke in T7 at WGI. A dozen faster places with more load and a less happy result.
05-29-2012, 10:38 AM
#14
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Yup.
I actually think my failure was due to me over torqueing that wheel and hence stub end with a defective 6' torque wrench the day before. Yes, I was lucky and yes, saw the video....insane. The in-car video is bone-rattling.
Yes, we do learn the hard way sometimes!
I actually think my failure was due to me over torqueing that wheel and hence stub end with a defective 6' torque wrench the day before. Yes, I was lucky and yes, saw the video....insane. The in-car video is bone-rattling.
Yes, we do learn the hard way sometimes!