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Wow, quite a thread. Will go through all 40 pages when I have some time, but the pics from the last few pages were disturbing. How do you even fix damage like this? I assume it's covered by warranty?
When you read the thread you will have your answer about how to fix it. Not aware of any being covered by warranty, but I'm not Yoda either. It is collision damage under auto insurance, damage caused by impact with another object. Unless of course your insurance company claims it is a manufacturing defect, then I'm not sure what would happen.
After seeing all the pictures of the failures and particularly the one here, I believe that the plates were designed as a safety device only, not as a reinforcement. When the top breaks off, the car loses all vertical support on that corner, which can have disastrous consequences.
I have heard this same explanation from a team that runs 991 Cups and works on 981 CS cars. While not what I would take authoritative, it was to my consideration, one of the better descriptions.
I have a set of the Motorsport tops but have not installed them as I do not see the benefit. On the BMWs I use to be involved in racing we welded a second strut tower before attaching the front bar points like you see in the Cup and CS.
While the Motorsport tops don’t offer any benefit as far as adding strength to the strut mount, it does offer some protection against losing control of the car on a highway or in a corner. I would definitely get one installed just for that piece of mind.
I’m also curious, with time and fatigue does anyone think this will become more common? I read earlier that the type of aluminum alloy is considered very strong, does that also imply that it won’t fatigue like regular aluminum?
After seeing all the pictures of the failures and particularly the one here, I believe that the plates were designed as a safety device only, not as a reinforcement. When the top breaks off, the car loses all vertical support on that corner, which can have disastrous consequences. These were designed for the 991 cup and 981 clubsport which are subjected to frequent hard hits when cutting across gators on track. With the plates - call them straps - the top of the shock is kept from dislodging entirely because the straps are bolted to much stronger areas on 1. the chassis (top left) and 2. the shock tower (bottom right in the picture).
They work the same in the street car, except that the chassis connection is another, not so strong connection to the side of the tower.
IMHO, the net result of putting these into your car is that it will keep the car manageable after it happened and possibly saves the hood from getting bent. The plates will not prevent the breakage from happening in the event.
^^ This makes sense & is completely plausible. In the video Mike Skeen's car went off the road & had a hard impact. Although there was structural failure of the strut tower, the strut didn't "pop up" like a jack-in-the box (refer to posts 597-599). The unsupported red car strut is completely unsprung & ~ 6-8 inches higher which translates to a front wheel going completely into wheel well. That would as cmosman indicated cause catastrophe/disaster. Mike Skeen's CS didn't roll-over & the secured motorsport plates kept jack-in-the box!
I had custom welding of the motorsport plate flanges to secure them similar to the Clubsport. I'll post pics soon.
Last edited by G-forceGT4; 02-09-2019 at 12:29 AM.
Strange, I heard that Porsche is offering a class to the IMSA teams on how to repair/replace strut towers. This would imply the corporation/Manthey are aware of failures. And there is the reported beefier towers on the 992.
As a vehicle development engineer and program manager in a previous life, I am well aware of structural damage from potholes and other like impacts. More than once, shock rebound force has been increased over what ride and handling specialists wanted — solely to keep the suspension from dropping to the bottom of the square-edged pothole on the durability test route. Big difference when the goal might be 400 cycles without a vehicle halting failure. On an attempted joint vehicle program between two major automobile manufacturers, the meeting between the facing test/proving grounds engineers got very emotional when discussing whose square-edged pothole test was more representative of the real world.
To the 981/991 issue, a bonded-in carbon fiber reinforcement probably would be the best solution for existing cars. Shouldn’t be too difficult to create the insert and use a relatively thick bonding agent to handle production tolerances. Certainly worth considering, if Porsche will not warranty a failed shock tower (is this definitely the case?). Since my current Porsche is “only” a 981 GTS, I don’t know if GT4 spring clearance to the strut tower would complicate the insert approach.
At the moment, I’m interested in this issue but not yet motivated as my current track day car is a Lotus Exige. If My dealer allocates one of his 718(982) GT4 allocations to me, then I could get motivated to action. 🍿
To those suffering a failed strut tower, I hope Porsche steps up and repairs or buys your car. Best wishes,
Bob L
^ Great post. If there is someone who could get that insert done in carbon-fiber, I may be interested also.
I never realized T6 at Thunderhill had such a big ditch at the outside of the curb. Good to know!
Every car has an Achilles heel, and while it appears that Porsche could have put a little more meat in the shock tower, or make the other components slightly weaker so that they would let go before the tower does, I don't think it qualifies as a design flaw or worry. Only so much abuse a car can take.
I once ran over a tall curb in my first e46 M3, and it bent every component of the front suspension. I remember the body shop commenting on how well BMW engineered it all, so that those components would take the brunt of the force, without damaging the frame. Then again, BMW complete failed on the design of the RACP (aka subframe) since thousands of those have failed and continue to do so. Like I said, every car has an Achilles heel, although in the case of the Cayman, it does not appear to be fatigue failure, just an example that you can not expect to get away with hitting a large pot hole or a curb.
Here is how I avoid it from happening, I turn harder and keep my front wheel in the air ;-)
Inside (unloaded) wheel/susp going over stuff is not the problem, whether the wheel is in the air or not. Outside (loaded) wheel/susp hitting stuff is what should be avoided whenever possible.
I never realized T6 at Thunderhill had such a big ditch at the outside of the curb. Good to know!
Every car has an Achilles heel, and while it appears that Porsche could have put a little more meat in the shock tower, or make the other components slightly weaker so that they would let go before the tower does, I don't think it qualifies as a design flaw or worry. Only so much abuse a car can take.
I once ran over a tall curb in my first e46 M3, and it bent every component of the front suspension. I remember the body shop commenting on how well BMW engineered it all, so that those components would take the brunt of the force, without damaging the frame. Then again, BMW complete failed on the design of the RACP (aka subframe) since thousands of those have failed and continue to do so. Like I said, every car has an Achilles heel, although in the case of the Cayman, it does not appear to be fatigue failure, just an example that you can not expect to get away with hitting a large pot hole or a curb.
Here is how I avoid it from happening, I turn harder and keep my front wheel in the air ;-)
I didn't see this youtube video posted before, so if I missed it apologies in advance. This car was in Scotland. I've seen some of their other videos where the driver tracked the car and took excursions off track after lurid slides. He says the strut tower failure occurred in routine driving, so an educated guess is that the initial crack occurred earlier.
I didn't see this youtube video posted before, so if I missed it apologies in advance. This car was in Scotland. I've seen some of their other videos where the driver tracked the car and took excursions off track after lurid slides. He says the strut tower failure occurred in routine driving, so an educated guess is that the initial crack occurred earlier.
Yeah...those guys really beat up that poor car. I wonder if all their video 'evidence' will effect how Porsche decides to deal with his issue.
I would think that this being a GT car, which is designed to take some track use and abuse, would not fail on routine use like this. Did they ride it hard?, maybe. But to cause this kind of control loosing damage, you should have to see more evidence, like a cracked wheel or a bulging tire. Most of the cases that have been shown, seem to happen in normal use. I think Porsche underestimated the necessary strength necessary for the application.
Inside (unloaded) wheel/susp going over stuff is not the problem, whether the wheel is in the air or not. Outside (loaded) wheel/susp hitting stuff is what should be avoided whenever possible.
Originally Posted by G-forceTarga4S
^^ Great advice. Looks awesome too!
I was kidding of course
Originally Posted by JPR
I would think that this being a GT car, which is designed to take some track use and abuse, would not fail on routine use like this. Did they ride it hard?, maybe. But to cause this kind of control loosing damage, you should have to see more evidence, like a cracked wheel or a bulging tire. Most of the cases that have been shown, seem to happen in normal use. I think Porsche underestimated the necessary strength necessary for the application.
Jpr
I agree, that is a design flaw for sure.
Just when I thought I was safe (coming from the e46 M3 rear "subframe" failure) I am in another car with an Achilles heel worry. On the M3 it was more of a metal fatigue type of thing, where on the GT4 it can fail from one bad incident . I don't see how this can be fixed/prevented without welding in some reinforcements, which is the last thing I want to do on a car with <5k miles. I wonder if they could make a stamped piece that fits underneath, between the tower and where the strut mounts? That would be a clean fix.
To my mind, as this Strut Tower can 'let go' through normal road use after just hitting a pot hole (an every day occurrence now days) resulting, as shown in all cases, with a complete collapse of the front suspension, then this warrants being labelled as a major safety issue. This is because the suspension, steering, handling and worse of all, the driver retaining control of the car, are all severely compromised. As a result serious injury or even death could be the end result! Sooner or later this WILL happen!
This design defect should be reported to the respective country's Vehicle Safety Authority for investigation with the intention of forcing Porsche to implemnent the necessary corrective mesures..
To my mind, as this Strut Tower can 'let go' through normal road use after just hitting a pot hole (an every day occurrence now days) resulting, as shown in all cases, with a complete collapse of the front suspension, then this warrants being labelled as a major safety issue. This is because the suspension, steering, handling and worse of all, the driver retaining control of the car, are all severely compromised. As a result serious injury or even death could be the end result! Sooner or later this WILL happen!
This design defect should be reported to the respective country's Vehicle Safety Authority for investigation with the intention of forcing Porsche to implemnent the necessary corrective mesures..
+1
The liability issue should be a gigantic red flag to Porsche.
You can pay me now. Or you can pay me (a lot more) later.
01-13-2019, 05:13 PM
