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I know it sounds odd, but nobody in Germany knows about this issue, discussed it with Manthey and they have never seen any cases (and they see a lot).
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
First post after lurking for a long time on Rennlist...
I had a deposit down on a 992 until a few weeks ago* so was consuming anything I could find on it. Interestingly, Porsche has strengthened the strut towers on the 992 with additional bracing. This is captured on page-86 of the workshop manual, with detailed pictures here: https://rennlist.com/forums/992/1119...l#post15513651
It looks like Porsche are recognising there is a weakness in the design they are compensating for.
* Since moved to a 981 GT4 (CS + LWB in Dark Blue Metallic) which I pick up next Friday!
I know it sounds odd, but nobody in Germany knows about this issue, discussed it with Manthey and they have never seen any cases (and they see a lot).
In my opinion nobody from Porsche or related to them(someone posted that PAG owns 51% of Manthey),will ever admit to failures like these!
Not surprising with all the other problems on previous models they never admitted to anything, never issued a recall, etc. They just fix it on the next newer model.
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?
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?
No warranty. You have to take the whole front end apart and check the frame tolerances (required from Porsche). Then you put it back together and the tower goes on with rivets and glue. Depending on what else they find its a $20+k bill.
I know it sounds odd, but nobody in Germany knows about this issue, discussed it with Manthey and they have never seen any cases (and they see a lot).
Just to back up this statement a little.
In quite some conversations with Manthey Racing and other racing & gentleman drivers, instructors, mechanics and others around the Nürburgring scene I have never heard of any strut tower failure on a GT4 or a GT4 Clubsport of anykind.
I know......but it makes you wonder why Porsche Motorsports designed them.
They were cheap enough even if they don't do anything.
The CS does have two cage tubes protruding from the firewall but they don't end on the top of the strut.
The failure could still happen in CS....
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.
Here's the photo of the damage to the CS
Is right along the bend of the material in that section.
Would have been great to see how they repaired the car.
electon mike's original post:
This brings back bad memories as this happend to a 991 GT3 I was buying when the tech did the PDI. He hit a curb on the test drive and did significant damage... I didn't take the car as it was messed up pretty badly, and they couldn't get another GT3 allocation.
in electron mike's photo, the jagged edge of strut tower hat failure shows the strut mount adjacent to the fractured aluminium hat. I think that mount "corner" transmitted excess force initiating the aluminium hat failure. It's possible that force could have been dissipated over a larger area with no failure. As Okie981 noted in a previous post, GT4 strut mount is smaller & more aft, which could cause this pattern of failure.
I'm not going to weld anything into the strut tower of my GT4. What I will do is talk to a local Porsche Meister tech who has a special interest in suspension, to see what they recommend. I hope known experts chime in on this thread soon. That would alleviate some anxiety & give us good idea on how to fortify this weakness.
And this one would have benefitted, as most of the others shown in the thread. Car must have been hard to control ...
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.
01-11-2019, 12:12 AM
Strut Tower Failure
