strut tower failure
11-21-2016, 02:56 PM
#137
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All non-GT car info about these failures is helpful to try and understand this. I don't agree that this shock tower rupture is acceptable, under any circumstances. It should have been stamped metal. Having said that, I'm more interested if any non-GT cars had this failure from "normal" use. Normal meaning thrashing the crap out of it on a race or autocross track, or driving on very rough public roads. For example, hitting a vertical curb that blows the airbags would not be normal use, so if the shock towers rupture there, so be it, I guess.
Last edited by okie981; 11-21-2016 at 03:16 PM.
11-21-2016, 03:31 PM
#138
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All non-GT car info about these failures is helpful to try and understand this. I don't agree that this shock tower rupture is acceptable, under any circumstances. It should have been stamped metal. Having said that, I'm more interested if any non-GT cars had this failure from "normal" use. Normal meaning thrashing the crap out of it on a race or autocross track, or driving on very rough public roads. For example, hitting a vertical curb that blows the airbags would not be normal use, so if the shock towers rupture there, so be it, I guess.
White Cayman S's impact looks severe and well outside any definition of normal use—but hard to say how bad the impact was vs. the outside sheetmetal damage...and one wonders if a stamped steel shock tower would have failed. My gut guess based on all previous experiences seen says no, but that's all it is—a gut guess.
What strut top is in that white car? Curious about it, as it looks like the car was modified. Need to go back and look at the wheel for obvious damage, too.
11-21-2016, 05:27 PM
#140
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The strut top looks to be the OEM part for 981/991 non-GT cars, just like the one in the photo of my BS earlier in this thread. And that's the same strut tower as in all 981/991 cars. Pretty nasty impact, but I believe like you, if it were stamped metal there would be no ruptured shock tower. Maybe a tweaked uni-body frame though. And the aluminum front sub-frame is another subject altogether as far as how it takes these impacts. But lots of cars are made with aluminum sub frames these days. BMWs, Audis, others I'm sure. I wonder if other OEMs are using cast aluminum shock towers......
11-21-2016, 06:42 PM
#142
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I remember early aluminum Audi cars, like the first A8, being kinda unimpressive in terms of their weight savings vs steel unibody cars. Yes, aluminum is lighter than steel, but when it is used for structure, you need more of it.
The metal in these 981/991 shock towers is THICK, but clearly can't take the sharp inputs that stamped steel towers have weathered for decades, even in rusty old Porsches with 300,000 miles. Wonder how much weight they saved...
The metal in these 981/991 shock towers is THICK, but clearly can't take the sharp inputs that stamped steel towers have weathered for decades, even in rusty old Porsches with 300,000 miles. Wonder how much weight they saved...
Last edited by stout; 11-21-2016 at 11:53 PM.
11-21-2016, 08:06 PM
#144
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Pretty sure these failures are undoing any marketing value-add, one $$,$$$ failure at a time. Hopefully, the folks inside are on it. I suspect someone like Mike Levitas could come up with a fix for this with a car on the lift, a beer in hand, and an hour to think about it. Porsche might be a bit quicker yet—if the right team can get through the red tape.
11-22-2016, 01:35 AM
#146
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Pretty sure the cast aluminum parts are more expensive than stamped steel parts.
11-22-2016, 08:24 AM
#147
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The cost may be very close either way. It's been a while since I did automotive component design, so I'm a bit rusty on cost estimating. Also depends on the amount of post-processing after the casting or stamping process.
11-22-2016, 08:55 AM
#148
They saw a need to reinforce the rear strut towers, but not the front except on the club sport which is a track car. Yet they market the street GT4 as a street car that is designed to track with the same strut tower as a base 981 boxster??
Last edited by 4carl; 11-22-2016 at 11:45 AM.
11-22-2016, 09:26 AM
#149
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Curious....I added JRZ pro...will this make the failure more probable or less so. On one hand, it won't easily bottom out. On the other, the springs are a lot stiffer.
