GTS-Jim

Maybe I missed it but appears to be 105 posts about a second hand account without the Facebook post or anything else for collaboration?

.2PDK

I believe the thread was started on the assumption that the second hand account was correct when in reality an entirely different situation.

As the towers on the 718 seem to be the same as 981 I was only inquiring if anyone has heard of the failure on the current models since this thread started.

.2PDK

This is what the tech at my dealer said. He has not seen any failures on 718s or 981s for that matter but has heard of them.

His theory is just that, stiffer suspension can weaken towers over time, this is why there have been no cases of failures in the other 718 variants (S, GTS) since they came out (to his knowledge).

Assuming they are also tracked and abused you'd imagine there would be just as many documented in the different variants.

Westcoast

Every report front strut tower failure that I could find followed a significant impact or off road incident. Determining this was time consuming due to the lack of disclosure by many of the individuals involved.

Also remember that any significant impact can be at fault including deep potholes or running up over a curb to mention only a couple, simply driving along a regular road as reported by some does not contribute to this type of failure.

ajw45

Those models along with softer suspensions also have longer travel (not as lowered). We're talking about going from a maybe 180 lb springs to 220, not huge. Huge is going from 220ish to infinity when the springs/shock fully compress and the suspension goes solid. Stiffer springs will decrease the chances of going to infinity and beyond assuming travel remains similar. I remember lowering my BMW and still having room for 7" springs after dropping the car over an inch. Depending on your set-up on the cayman if you drop the car further and/or use helper springs you're looking at a 5" spring and less than 2" of suspension travel before the spring or shock fully compresses.

Archimedes

This. x100.

Denny Swift

Yes, that was my assumption too, but I still disagree that damage is more likely to occur with a softer suspension. And I haven’t seen any proof that failure occurred only with the suspension bottoming. A really fast hard hit on a shock is like a really fast hard hit on water skis. If you hit the water at 60 mph it’s going to feel like falling onto concrete (and much different from a 25 mph fall). If your suspension hits the sharp edge of a pothole or a curb at high speeds, it will impart a severe blow to the support with minimal travel (more so the stiffer the suspension). Similarly, you’re more likely to crack a wheel with stiffer suspension and can certainly do so without the suspension bottoming. This is just interesting conversation in terms of the 718. Hopefully, Porsche strengthened the design of the towers on the 718.

Zhao

My education on aluminum is old and my brain is pretty much useless thanks to this year so take this as opinion instead of fact:

I'm not too worried about the strut tower failure problem happening on the 718s. The 981 strut tower problem looks like an cast aluminum problem (I'm not 100% sure the towers are cast aluminum, but the sheers on the 981 GT4s look like they are cast, and I'm not sure how they'd give that portion of the car the strength it needs in aluminum without using castings), with it being too brittle, probably from manufacturing it improperly (heat treating it or something else) when the bends are formed. I would definitely call that a design flaw, but it's not uncommon for strut towers to take massive forces from impacts. I inspected an Acura MDX that hit a chunk of cement on the highway; it inverted the strut tower on the impact side of the vehicle and put a diagonal buckle in the roof from the body flexing so much. Aluminum is far more brittle than steel so what may only bend steel, may split aluminum. It's pretty common for cast aluminum suspension components to completely sheer in half under any sort of decent impact. Sheered strut tower tops are rare probably only because so few vehicles are built with inner structures of aluminum.

Change ups are pretty common on vehicles and some manufacturers can have multiple of the same part within a year (seen dodge do that). So it would be very weird if Porsche did not look into this problem and quietly do a change up on the part with a different process of manufacturing, increased thickness, or different heat treating or whatever so that the 718s do not suffer from the same problem as the 981. It also could be a bad run where there never was a design flaw and it was just a month or 2 their production of the aprons were out of tolerances for heat treating or whatever that caused them to be more brittle and less tolerant of impacts.

The only thing I do not like is if this is purely from impacts, something else should have been engineered to bend or sheer before this happened. Generally on a suspension hit you should see components closest to the wheel fail or get compromised first. Example: You don't have a bent sub frame unless you have a bent control arm.

.2PDK

I believe they're the same but could be wrong.

This.

s2kspyder

Does anyone know if the spring rates and shock valving is the same between 981 and 982? I know the PASM settings are different.

981 F 257 ft/lb R 457 ft/lb
718 ???

Bluelinebroker

Hi all. Good reason. I bought this car wrecked and need some structure parts. One is the passenger side mount. No dealer as of yet will sell to me as they want cert shop. Has anyone produced after market? Anyone help me get one ? Thanks

Antipodean

Porsche supplies them to certified repairers only. Certified repairers have the expertise and tools (esp. the celette) to effect a safe restoration. Do you?

Zhao

Going to be brutally honest here. You're in over your head.

If you were in the industry you'd know Porsche only releases that to a certified shop and you'd know there is zero chance of aftermarket strut towers. No one makes aftermarket strut towers for a toyota corolla let alone a Porsche.

Whoever is fixing the car for you is also in over their head as they should have answered those questions to you instantly.

It will also be next to impossible for you to find a certified shop that will sell you those parts. Knowing the types of owners and people that run a shop of that caliber having worked at a high end shop before, I think most of them quite literally would rather cancel their insurance and then burn their shop down rather than sell you structural parts. Sell the car back through copart or wherever you got it from, or have a certified shop change the strut tower which frankly is not a crazy expensive repair compared to doing some other body repairs on Porsches.

okie981

I will never claim to know everything about anything and make conclusions about something unless I have hard reliable data to make a conclusion from. Anecdotally, sure, you appear to be correct that everyone "hit something". Based on the lack of incidence of this strut tower failure since a rash of ones around the 2017 timeframe, I'll go out on a limb and say there was a run of sub-standard parts making their way into assembly lines. When installed in cars that have low ride heights (981 GT4) without much rubber snubber motion attenuation at limits of shock compression (981 GT4), they were prone to fail at the weakest point. But, that's conjecture on my part, armchair analysis of anecdotal data. Have these cars just stopped "hitting something" and that's why few or no additional failures have occurred for some time?

Recall @Joe Weinstein never "hit something" but he had lowered his car and was a serious autocross competitor. His shock tower failed after hitting a typical dip on a highway like we all hit, i.e. bridge transitions, pavement transitions. Not a pothole, not a curb, typical highway crappy roads. His (I'll conjecture "defective") shock tower was likely weakened by autocross at lowered ride heights, and then upon a bit of road driving, the final stress occurred that caused fracture.

strut tower failure - Page 5 - Rennlist - Porsche Discussion Forums

lnirenberg

On some turns head up & eyes focused on the next corner I use the curbs for a physical confirmation I hit the apex. The curbs are gently sloped and I have never had any damage from track driving in this manner. The GT cars are very specifically built with increased track focus vs the more pedestrian models and if this type of driving causes physical damage it is a design issue. Assuming I get my car early enough this fall to get the break in miles before winter sleep I will find out next spring as my driving style will not change. That said, potholes are a feature in northern climes so the 1st thing I would do if this happened was get the wheel fixed before I take it to the dealer.