strut tower failure
#392
Three Wheelin'
#395
A metalurgical post-script...
I was able to get the part examined (thoroughly but 'unofficially'*) by a metals lab, and there were some aspects of interest.
They were not told, but from their tests they were able to identify the metal as from Porsche, because it is apparently a proprietary aluminum alloy that is very strong. I would guess that any shop that ever simply tries to weld one of these back together would be fighting a metallurgical battle they couldn't win.
They found that my part had two fracture surfaces, meaning that a crack had occurred much prior to the date of my road incident, and the complete failure was induced by enough new jolting to break the rest of it. It seems we should define a regular inspection protocol for this part, and perhaps a concerted consideration of the club-sport reinforcement part, and a write-up on what it takes to install? I still have most of the broken part to examine. I would want to make sure the reinforcement actually added support where the fracture occurred...
*The information was delivered unofficially, delivered by word-of-mouth only, for free as a kind and generous professional courtesy. They can make this information available in a formal detailed official engineering report, for a time, if it is paid for, and it is not likely to be cheap. This is because an official report exposes the testing company to time spent later, in involvement in any business or legal proceeding in which the report might become material.
HTH,
Joe
They were not told, but from their tests they were able to identify the metal as from Porsche, because it is apparently a proprietary aluminum alloy that is very strong. I would guess that any shop that ever simply tries to weld one of these back together would be fighting a metallurgical battle they couldn't win.
They found that my part had two fracture surfaces, meaning that a crack had occurred much prior to the date of my road incident, and the complete failure was induced by enough new jolting to break the rest of it. It seems we should define a regular inspection protocol for this part, and perhaps a concerted consideration of the club-sport reinforcement part, and a write-up on what it takes to install? I still have most of the broken part to examine. I would want to make sure the reinforcement actually added support where the fracture occurred...
*The information was delivered unofficially, delivered by word-of-mouth only, for free as a kind and generous professional courtesy. They can make this information available in a formal detailed official engineering report, for a time, if it is paid for, and it is not likely to be cheap. This is because an official report exposes the testing company to time spent later, in involvement in any business or legal proceeding in which the report might become material.
HTH,
Joe
#396
#397
Rennlist Member
I was able to get the part examined (thoroughly but 'unofficially'*) by a metals lab, and there were some aspects of interest.
They were not told, but from their tests they were able to identify the metal as from Porsche, because it is apparently a proprietary aluminum alloy that is very strong. I would guess that any shop that ever simply tries to weld one of these back together would be fighting a metallurgical battle they couldn't win.
They found that my part had two fracture surfaces, meaning that a crack had occurred much prior to the date of my road incident, and the complete failure was induced by enough new jolting to break the rest of it. It seems we should define a regular inspection protocol for this part, and perhaps a concerted consideration of the club-sport reinforcement part, and a write-up on what it takes to install? I still have most of the broken part to examine. I would want to make sure the reinforcement actually added support where the fracture occurred...
*The information was delivered unofficially, delivered by word-of-mouth only, for free as a kind and generous professional courtesy. They can make this information available in a formal detailed official engineering report, for a time, if it is paid for, and it is not likely to be cheap. This is because an official report exposes the testing company to time spent later, in involvement in any business or legal proceeding in which the report might become material.
HTH,
Joe
They were not told, but from their tests they were able to identify the metal as from Porsche, because it is apparently a proprietary aluminum alloy that is very strong. I would guess that any shop that ever simply tries to weld one of these back together would be fighting a metallurgical battle they couldn't win.
They found that my part had two fracture surfaces, meaning that a crack had occurred much prior to the date of my road incident, and the complete failure was induced by enough new jolting to break the rest of it. It seems we should define a regular inspection protocol for this part, and perhaps a concerted consideration of the club-sport reinforcement part, and a write-up on what it takes to install? I still have most of the broken part to examine. I would want to make sure the reinforcement actually added support where the fracture occurred...
*The information was delivered unofficially, delivered by word-of-mouth only, for free as a kind and generous professional courtesy. They can make this information available in a formal detailed official engineering report, for a time, if it is paid for, and it is not likely to be cheap. This is because an official report exposes the testing company to time spent later, in involvement in any business or legal proceeding in which the report might become material.
HTH,
Joe
Extremely interesting, and thank you for doing this for the community, Joe.
#399
#400
Drifting
I was able to get the part examined (thoroughly but 'unofficially'*) by a metals lab, and there were some aspects of interest.
They were not told, but from their tests they were able to identify the metal as from Porsche, because it is apparently a proprietary aluminum alloy that is very strong. I would guess that any shop that ever simply tries to weld one of these back together would be fighting a metallurgical battle they couldn't win.
They found that my part had two fracture surfaces, meaning that a crack had occurred much prior to the date of my road incident, and the complete failure was induced by enough new jolting to break the rest of it. It seems we should define a regular inspection protocol for this part, and perhaps a concerted consideration of the club-sport reinforcement part, and a write-up on what it takes to install? I still have most of the broken part to examine. I would want to make sure the reinforcement actually added support where the fracture occurred...
*The information was delivered unofficially, delivered by word-of-mouth only, for free as a kind and generous professional courtesy. They can make this information available in a formal detailed official engineering report, for a time, if it is paid for, and it is not likely to be cheap. This is because an official report exposes the testing company to time spent later, in involvement in any business or legal proceeding in which the report might become material.
HTH,
Joe
They were not told, but from their tests they were able to identify the metal as from Porsche, because it is apparently a proprietary aluminum alloy that is very strong. I would guess that any shop that ever simply tries to weld one of these back together would be fighting a metallurgical battle they couldn't win.
They found that my part had two fracture surfaces, meaning that a crack had occurred much prior to the date of my road incident, and the complete failure was induced by enough new jolting to break the rest of it. It seems we should define a regular inspection protocol for this part, and perhaps a concerted consideration of the club-sport reinforcement part, and a write-up on what it takes to install? I still have most of the broken part to examine. I would want to make sure the reinforcement actually added support where the fracture occurred...
*The information was delivered unofficially, delivered by word-of-mouth only, for free as a kind and generous professional courtesy. They can make this information available in a formal detailed official engineering report, for a time, if it is paid for, and it is not likely to be cheap. This is because an official report exposes the testing company to time spent later, in involvement in any business or legal proceeding in which the report might become material.
HTH,
Joe
So, what was the unofficial failure mode of the original crack?
#401
As I recall, the implication was that it was also impact-originating, as opposed to any gaps/imperfections in the metal. I cannot think of any prior impact though... Bumpy roads at worst. No air, no track days, so no corner kerbs etc.
#402
Burning Brakes
Another thank you for all you have posted about this. Was your car ever driven by anyone else that could have contributed to the problem?
#403
25 miles on it at delivery, and only left at the dealer once for an oil change at 1100 miles. Neglected to check the in/out miles for that visit (not yet that paranoid)
#404
Rennlist Member
Still, there are a lot of cars out there running with no problem at all. So it seems to be a freak occurrence, or near freak occurrence—but it would be wonderful to understand this better. We may never get there, but your work and the work of others has shed some invaluable light on the incident with your car. Good to hear the piece is made of super strong material, still wondering whether the analysis company can tell us more, politely and off the record (is it brittle? is it a good use of said material? etc) in its opinion. Wonder if the first impact even happened in some aspect of the shipping/delivery.
#405
Aren't the cars driven on and off the RO-RO vessels? In my shipping experiences, while complaining about the cost of some crates, an export packer once told me, "A stevedore could tear up a bowling ball with a cigarette paper."