Diablo Dude

Agreed.
And it would be helpful if someone could develop a data-base (ala: 3rd gear failure) with mileage, build-date, and track days.

911-140.6

I think they'll help a lot . Got my set the other day. I've also consulted with my future son in law who is a Structural Engineer as far as what I can do to transfer and mitigate vertical load on our strut towers. I'll report back if we come up with something.

One of my thoughts was based on using Aerospace grade carbon fabric applied using epoxy.
Airbus, Boeing, etc have used this method on load bearing surfaces like ailerons, landing gear doors, rib tubes, etc....things that take a beating and carry compression . I just need to find out if proper curing can be done in ambient temps vs hi temp baking like the industry does. I truly don't mind wrapping the entire towers on both the inside and out if it means not breaking. I don't think I'll ever sell my GT4 so not too worried about how it will look.

3M makes a product call Scotch Weld DP420 which should be able to create a bond .

High modulus carbon is what I'm aiming for as the bike industry uses it via vacuum press and w/o baking .

Here's a quote from a materials abstract by SciELO Analytics. The failure modes achieved were quite high...considerably more than what our cars would go through from slamming a pothole or track curbs...at least in theory.

Carbon fabric/epoxy composites are materials used in aeronautical industry to manufacture several components as flaps, aileron, landing-gear doors and others. To evaluate these materials become important to know their mechanical properties, for example, the tensile strength. Tensile tests are usually performed in aeronautical industry to determinate tensile property data for material specifications, quality assurance and structural analysis. For this work, it was manufactured four different laminate families (F155/PW, F155/HS, F584/PW and F584/HS) using pre-impregnated materials (prepregs) based on F155TM and F584TM epoxy resins reinforced with carbon fiber fabric styles Plain Weave (PW) and Eight Harness Satin (8HS). The matrix F155TM code is an epoxy resin type DGEBA (diglycidil ether of bisphenol A) that contains a curing agent and the F584TM code is a modified epoxy resin type. The laminates were obtained by handing lay-up process following an appropriate curing cycle in autoclave. The samples were evaluated by tensile tests according to the ASTM D3039. The F584/PW laminates presented the highest values of tensile strength. However, the highest modulus results were determined for the 8HS composite laminates. The correlation of these results emphasizes the importance of the adequate combination of the polymeric matrix and the reinforcement arrangement in the structural composite manufacture. The microscopic analyses of the tested specimens show valid failure modes for composites used in aeronautical industry.

ExMB

There are already picture posted of those installed. They really don't go to anything worthwhile on the frame in the street version. Keep in mind that in the CS the front cage portion goes through the firewall and is attached in the frunk area.

jmartpr

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....

Pruettfan

Well this thread has cured my GT4 fever. Given the way most of these cars are rarely driven and only one failure we know of took place at a track this appears to be a real issue and worthy of concern. I would be buying a GT4 to be a track car primarily so this potential weakness is a real red flag for me.

benben01

This is no way to start off the new year "jlennox"... Hopefully you can get it fixed and reinforced. I lost 2 sets of rims last year thanks to highway potholes at night time on my S4 and my wife's C63... Does any remember if BGB or some other vendor was looking into making reinforcements for 981 and 991 shock towers?

jmartpr

If you plan to track a GT4 a lot IMO 19" wheels/tires are a must.....not only you save $$$ on the long run while having an extra set of wheels/tires, the extra meat on the side wall to keep the diameter as close as possible to stock adds more compliance and cushion a bit more the impacts.

olmy

I remember watching the "Porsche Challenge at Pikes Peak" video from Motor Trend when it was released and wondering if anyone else noticed the strut tower failure due to an off track incident.

Granted this a bit more than hitting a pothole ...

Skip to 12:42 :

jmartpr

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.

d00d

I thought Pikes Peak was hairy until I saw this;

okie981

Same exact failure mode we've seen on non-CS cars. This unfortunately seems to indicate the bracing on top of the CS shock towers isn't intended to reinforce the shock tower, it's meant to anchor the roll cage and shock tower together, possibly for more overall rigidity in chassis flex. I'm of the opinion the solution will come from outside Porsche with a reinforcement "bucket" made to conform to the inside of the shock tower and set in place with the same adhesive used to assemble many of the structural parts of the car. Material could be steel, aluminum, or possibly carbon fiber. This is why earlier in this thread I was seeking to obtain a brand new shock tower, so I could do some analysis on a scanned 3D model of it and do the same analysis with a bucket attached to the inside. Of course doing a mod like this will only reveal the next least strongest part of the suspension and/or structure.....

okie981

Earlier in this thread there were some posters who expressed their dislike with this being a sticky because it was believed to be more of a freak occurrence and it would put a cloud over the GT4 and other 981/991 GT cars. I posted that it didn't make me any difference either way because I intended to proceed with obtaining a new shock tower part and work on designing a solution. If you read this whole thread you will see that I had to give up on getting a new part because it is very tightly controlled by Porsche. I tried several angles of attack to obtain a part. No can do. Without a new part unassembled from the car it will be sub-optimal to try and get a good 3D scan, at least it would be with the scanning equipment I can get my hands on.

If anyone knows a moderator and would like to see this a sticky, please contact them or post the moderator's name in this thread (or PM me).

venom51

It's a cast part..my guess is the failure is the result of casting defects in some but not all castings. That's why it's not a larger scale issue.

4carl

Sven76