Definitely need an engineered solution, but I am surprised that none of the aftermarket has hopped to on this. Whether thin steel or CF, an inverted "bucket" that is epoxied in place could prevent a $$,$$$ repair—or worse. Front dampers would have to come down/out, and then some method of bonding them in, and then the (minimal) added thickness accounted for with the spring perches. Done.

 

The idea of a stiffer spring is something I keep coming back to as an interesting concept and has been my primary dislike of the car on track. While a higher spring rate would seem to transmit more stress, I could see how it may also aid in keeping that stress below a key threshold in extreme cases like bottoming out, or other.

Are there any mechanical engineers out there that would be able to talk through the higher spring rate consideration?

So far i have kept away the curbs as much as possible and have played around with various configurations for my DSC box that helps to compensate for the nose dive I disliked on track.

Though, it is still possible that there could be a few pieces that simply were not up to quality control levels specified but yet passed along from suppliers, which given the transmission threads, seems plausible.

 

 

 

 

 

 

There is probably some primer and paint in there that needs to be removed, otherwise the epoxy wouldn't have a good bond with the aluminum strut tower casting.
Since the 992 apparently relies on two links to fortify the area, I could see the proposed insert similarly bolted to the inner sides of the tower in at least two places.
The insert could extend further down with a lip underneath the frame rail for greater mechanical advantage like Carl describes.

 

Can we make a push again for this to be a stickie?

 

Yes, that is what I thought as well. Sounds good in theory, except the bonding thing is possibly tricky, as stated below.

Next time I have my car on the lift I will take a look at it. Ideally someone with a modern 3D scanning tool could get a model of the area and then design and fab an insert. A time consuming endevour. But it would probably sell like hot cakes if there was a kit for it.

 

A cup insert from below would rob from valuable, limited shock travel our cars suffer from with the factory dampers. The only way I'd consider this is with a move to a shorter strut.

 

Some quick thoughts as a mechanically minded person—but no engineer!

I'd be curious to hear someone like PeteVB or Robert Linton weigh in on the importance of the bonding agent in this scenario, as the real goal is to spread the load and the piece would obviously be held up (and pushed up) by the strut itself. Might not need much (or, effectively, any?) help from the body agent to stay in place. Question becomes what's the best way to spread that loading so the tower top doesn't take the whole hit. And, of course, what happens as that load is spread.

Agree x2.

This is where some thoughts from someone like PeteVB or Linton would be interesting to get. There are other very bright minds here with experience in this area, too. Keys would be to come up with the thinnest/strongest solution possible—which would to me suggest carbon-fiber. If we are talking about something washer-thin, I wouldn't hesitate to install it and I wouldn't worry about shortening dampers, etc. That's well within the tolerance of ride height...or if I had to raise the rear by a washer to match the front end that's a washer higher, I'd happily do it.

 

I've done 6 Tarmac Rallies (and a lot of track days) and both the front and rear shocks have bottomed out, coil bound, massively 100's of times on very bumpy closed roads, I simply cannot believe my car's in one piece after reading this thread ( I hope I haven't jinxed myself). On these rallies there a 2 people in the car, I have a full cage, fire extinguishers etc and with a full tank the car weighs in total 1600kgs. that's on the heavy side and the strut towers have held up. As its a cast mount there must be variations in the quality of the casting for a pot hole to do this to some cars.

Last year due to the front shock hitting the bump stops so much with so much force I installed longer travel Tractive Shocks, this may have been saving my car for the last 4 tarmac rallies.

anyone have any feedback on the SP motorsport solution? it looks like the strut tower would just peel away regardless doesn't it?

 

With anything cast, chemistry of the metal and heat treatment determine the final strength. The least destructive way to determine what each chassis has in place would be to verify the hardness. Equotip though not widely accepted as being repeatable is the least intrusive followed by rockwell. To really understand, a destructive sample would have to be extracted and charpy impacts performed. If anyone who has experienced a failure can obtain a sample of the broken strut tower, I'll take it from there. If we have low impact resistant strut towers in our cars, a reinforcement really won't do much to prevent the failure unless it essentially replaces the entire strut tower and ties back to sound material.

 

Off topic, but do you have any videos of the rallies? Love to check it out!