North Coast Cab

I'm no engineer....but for existing units I would add a longitudinal steel to the center tube as well as a piece of 1/4" angle to the bottom of the center tube for strength. I would also weld on tabs in the center to mount to the body like the Kokeln one.
As a redesign I would simply beef up all the components, as well as add the center mouting tabs.
I sure hope someone keeps this moving forward. The 944 is an awesome track/race car and things only add to the excitement.

Eric_k

This weekend I did 6 races (12 total sessions) on a fast and bumpy Spokane track with no issues from the rear suspension. I did keep a close eye on it though.

I won 1 race and got to within 9 hundredths of a second of the class track record. It does make a difference.

theamsoilguy

My plan is to 1) hear more about this, 2) make it stronger by doing what the owner of the piece that failed suggested. I wont re-powerder coat it or paint it, maybe just a clear coat to stop rust. That way I can inspect for cracks, etc.
I think I need to install it to fit the extra tabs and check for clearance to know where to beef it up, a simple angle iron on one edge would probably do the trick with the tabs added.

900 rear springs, 400 HP so Im in the same boat

333pg333

So we know of at least 3 cars out there racing these. Any more? Only one failure so far.

theamsoilguy

I think the key is ones racing with 800-1000 springs as lesser more streetable ones might not cause a failure if your looking for comparables I think that would be the important piece.

TonyG

But...

Since race cars don't run rubber motor mounts:

P = 0

Thus Ma = 0

And if Ma = 0, Ra=0


And even if there were rubber motor mounts... the the forces we are talking about here are trivial.


TonyG

Max Energy

Guys,
I run 900# springs with no problems so far.
Max

CyCloNe!

I wonder where Bruce is at? Any one contact him, I would think his input would be most important here since it's his product.

mikey_audiogeek

Hi Tony, since I'm a pedantic mechanical engineer, I'll just mention that the forces and moments are unchanged, irrespective of rubber or solid mounts - it's just that the displacements are different.
F=-kx and all that. (Mr Hooke and Mr Newton again). Solid mounts don't eliminate forces, or moments!

(I know this stuff pretty well, even though I wish I was as good at my job as you are at yours )

Agree with you that the forces are trivial, which still begs the question: short of running over the crossmember with a forklift, what could possibly cause it to fail like that? Any new ideas?

Cheers,
Mike

Dutch944

By the way, there is a 968racer here which also uses this torsionbar. No problems at all, but i'll address this problem to them, maybe they have some extra input on this issue!

TonyG

Who really knows for sure what caused it. I'd have to have it here to actually look at. None of it really makes sense.

It's hard to tell from the pic, but it sure seems that either the car hit something, or one side of the suspension carrier came loose from the body, which then had no support and bent. But even then it's hard to imagine the tube bending like that.

Once it started to bend even a little, the rear alignment would be so far out that you'd know there's something drastically wrong and would pull in to the pits.

How you could keep driving to the extent that it was deformed like that is very strange.

TonyG

333pg333

Be good to get more pics from the OP??

333pg333

SPAM SPAM

disasterman

Glad I have the original Kokeln right now. If anyone wants measurements from it or photos let me know.

TonyG

FYI.... I can get Vision to make some of the rear suspension units if anybody is interested. But they get about $2k for the setup. And no... they won't fail.

TonyG