Location: Location Location NW Suburb Of Chicago, USSA
Weird (aftermarket) suspension failure.
Cruise-In attendees and followers are probably already aware that I had a significant suspension failure on my Z06 in Bowling Green.
There was a 6x6 or 8x8 piece of lumber in the road. Because of oncoming traffic, I couldn't move over far enough to miss it completely. There's not a mark on my bumper, so it appears that I hit it with the Gurney lip and the little bit of tire that sticks out. The impact punched out the coil-over mount but, as near as can figure (mechanics will be looking at it after the holiday) there isn't any other damage. (Pictures below.) The wheel has no scratches, dents or dings, and the tire is still holding normal pressure.
Since this is the first time I've banged up a Corvette, I'm looking for commentary on things to be sure to check for during the repair process - what little details need special attention to be sure the car gets back to factory standard condition, and where will it never make it back?
FWIW, it's a complete Pfadt setup - coilovers, sways, camber kit, and bushings.
wow that sucks...glad iy didnt mess anything else up....I dont think you'll really be able to tell anything else until you get it fixed....then youll be able to tell what else happened.....I was ran off the road in my camaro ss a few years ago...had a set of aftermarket wheels and it was lowered. I got cut off and nailed a 6inch high curb....completely snaped 2 rims.....didnt do any other damaged though. I was really suprised.....so you never know
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Quote:
Originally Posted by RC45
I recall a number of folks asking about the rumoured weakness in the shock mount area... but they were chased off as fear mongers and nay-sayers.
I guess the upper shock mount is a weak point in the Vette chassis, since it is designed for transverse leaf springs... not coil springs.
Wow, That right there is proof that is hard to deny. I wonder if the same would have happened with the steel frame of the standard C6? It looks like you can see the piece of aluminum frame ear punched right out inside the upper mount?
Coilovers had absolutely nothing to do with this. The driver drove over a friggin log the size of a 6x6 or an 8x8.
Hmm - coil overs had nothing to do with this?
So in your opinion, the forces acting on the upper shock mount are no more with a coil over setup than a transverse leaf setup while driving over an 8x8 log?
I would rather say that it is possible the use of a coil over contributed to this failure - afterall, we really dont know do we?
Anyway - there were a number of comments from supposed GM source about the weaker aluminium upper shock mounts.
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Quote:
Originally Posted by WFO
Coilovers had absolutely nothing to do with this. The driver drove over a friggin log the size of a 6x6 or an 8x8.
So you believe if he had hit the same thing with stock suspension that the factory shock would have punched through/sheared off the the upper shock mount?
I realize that he drove over a railroad tie sized piece of lumber. What I would worry about would be the GM designing that went into the shock mounting point wasn't spec'd for a coil over setup. The lumber caused a sharp impact leading to catastrophic failure. Would repeated track days cause the upper shock mounts to distort or metal fatigue?
So you believe if he had hit the same thing with stock suspension that the factory shock would have punched through/sheared off the the upper shock mount?
Or possibly worse my friend..
Why do we argue over this crap?
Drive over a 6"-8" friggen log and you should expect some pretty good damage to an expensive, highly computerized, precision light weight sports car like a Corvette.
Moral of the story: Drive your truck over crap like this...then, hold your stones. Otherwise give yourself plenty enough room between vehicles to make corrections, braking and otherwise. Continue daily to dodge life's "unforunate incidence bullets" as they get thrown at you and hope for the best.
Look at the structural damage incidence rate for coilover users, not very common if at all.
I realize that he drove over a railroad tie sized piece of lumber. What I would worry about would be the GM designing that went into the shock mounting point wasn't spec'd for a coil over setup. The lumber caused a sharp impact leading to catastrophic failure. Would repeated track days cause the upper shock mounts to distort or metal fatigue?
First of all thank goodness he is alright because this could have caused an accident.
Secondly, he did indeed drive over a log sized piece of wood. You would expect damage after that, however, is it reasonable to expect this much damage?
Dang, a Katech Z too. Wonder what the repair will involve.
I respectfully disagree. This is a prime example of what can happen when you impose loads on a structure (the shock mount) that it was not designed or tested to resist.
You modify cars at your own risk. I am willing to bet money that this failure WOULD NOT have occured if the car had the OEM leaf springs.
Look at the structural damage incidence rate for coilover users, not very common if at all.
This is just arm-chair quarterbacking.
Yep - the very same arm chair quarterbacking done by the actual pro-rce teams who decided to go with the steel chassis vs the aluminium chassis o fthe C6 Z.
I am guessing there is a reason fo rthis - besides cost.
I do believe Short Throws car is based on a steel C6 chassis, not the alumium one - and I think it is safe to say that was a not a decision based purely on the cost of the steel vs alumium chassis.
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Quote:
Originally Posted by gonzalezfj
I respectfully disagree. This is a prime example of what can happen when you impose loads on a structure (the shock mount) that it was not designed or tested to resist.
You modify cars at your own risk. I am willing to bet money that this failure WOULD NOT have occured if the car had the OEM leaf springs.
Frank Gonzalez
And anyone that thinks otherwise is deluding themselves or does not understand the suspension configuration. This is not a knock on coilovers at all, lots of people use them and love them but, with the aluminum frame of the Z06 one has to wonder about longterm stress and fatigue damage from coilovers.
Correct me if I'm wrong; but after looking the picture several time, does that picture shows that the shock mount/tower gave in and the coilover shock went up & through the shock mount/tower? In addition, if I may, how fast were you going when you hit the lumber? TIA Glad you ok and the car does not look too bad. Thx again!
Location: Location Location NW Suburb Of Chicago, USSA
Quote:
Originally Posted by 1stZ
Correct me if I'm wrong; but after looking the picture several time, does that picture shows that the shock mount/tower gave in and the coilover shock went up & through the shock mount/tower? In addition, if I may, how fast were you going when you hit the lumber? TIA Glad you ok and the car does not look too bad. Thx again!
I was braking down from 45 or so - going 25-35 when I hit it. Yes, the coil-over shock mount failed. There is fiber showing around the pushed-up area. There were pieces of some kind of cast aluminum disk in the engine compartment. I'm guessing that this was the actual mounting point under the chassis, and it broke into 3 or 4 pieces.
Quote:
Originally Posted by captain454
If one runs coil-overs and experiences this sort of failure, is there permanent damage to the frame of the car?
That's what I really want to know. Hopefully I'll know in the next few days.
Quote:
Originally Posted by Randy@DRM
I would love to see pictures of the upper top hat from the inside. IL, umm, maybe I will head that way to take a look???
Please do & share with us your findings. Hopefully we could learn something that would help us (wishful thinking maybe?!) improve or even better come up with a fix to it.
Corvette Store
Weird (aftermarket) suspension failure.
That right there is proof that is hard to deny. I wonder if the same would have happened with the steel frame of the standard C6? It looks like you can see the piece of aluminum frame ear punched right out inside the upper mount?
