Torque bar snapped!
 

It finally happened! One of the bar snapped at the area where bar meets the screw on head, the bar connecting the trans fork to the top of the shock mount. Now I've got to drive slower as I've got monoball spring plates and no torsion bar. I'll get the welder to make a similar bar but maybe out of iron! :(

Which bar/brace are you using? CSP? First I've heard of one snapping... :confused:

Yes the CSP's torque bar! My mechanic told me when installing that it wouldn't be that strong plus not using torsion bar, the bars especially the ones from the horn to top shock mount will be under alot of stress and also taking the bulk of the cars weight. I'll try to take some pictures of it and post it. :(

Sad, but also very cool that your engine has such a power that it would break a torque bar!! :eek:

What engine did this?

Thanks for sharing :D

Wally, I dont think its my engine which snapped the bar, but most likely my style of driving. I enter and exit coners at high speed till the tyres start screeming. I guess that plus very hard setting of the rear dampers could be also facts contributing to the failure!
Btw its a small engine :o 88x69 w110 44 heads stock carb, bas exhaust. :o .
But animal is being chained till next month. T4 103x80 schl.340 48x40, 48idfs,remmele's exhaust. :)

Now, you are talking :D

OTOH, its still very weird that the bar snapped. The load is supposedly along the axis of the bar. Breaking it that way is very very difficult. I would suspect a less than ideal installation.
Way more powerfull cars with way harder suspension have used these bars with drag race starts many times over without failure, so it is hard to believe its a design fault...
Welding the taps straigth towards the direction to which the bar attaches to is critical to avoid lateral stresses. The bar is not designed to take lateral forces.

Anyway, please, do show pics and specs of your future engine ;) Sounds spectaculair!

Thanks,
Walter

i heard it before that the csp tourque bar snapt under a little stress for a long time. thats wy i didnt buy one.

Hello,

This brace was developed and used by a lot of German KaeferCup racers, so high cornerspeeds shouldn't be the reason for breaking.
I think the bar has been preloaded when the wheels were off the ground.
Another possibility could be that there has been some misalignment in the mounting of the bar, but my guess is preload.

Cheers,
Richard

Just have to ask a dumb questione as im mounting mine soon : You meen preload as when in a driving situatione , or by having the car on stands with no weight on the frame during mounting etc .
Regards

Puma-alex

Hello,

I meant (too much) preload on the bar during installation. After putting the car on its wheels, the load on the bar is even more so this could be the reason for breaking. But, as said, it's my guess, I would mount it "loose" and turn the bars to a snug fit after putting the car on its wheels.

Cheers,
Richard

Any of the possibilities could have caused the failure, but its about more that a year and half before the failure since the installation. AS I'm out of town now, and according to my mechanic, he said that looking at the cross-section of the bar, 2 different shear marks, meaning that an earlier hairline crack/fracture might have been the start of the failure and was at the thread end. Anyway its been welded back and going into the car. :o

Sorry to hear the Beetle is sick.

Do you have a close up pic of the break? That will tell how and why it failed. There is a few scenarios that can be pin-pointed. Fracture mechanics was one of my hot subjects at University.

I've not seen a 'bolt-on Kafer-bar' set up yet that impresses me, even the new Bugpack piece looks medioka. The CSP looks alright, if it wasn't for the cantilever tabs, which result in improper triangulation. I don't believe this'll be the first failure of this type when using monoball. Are you concerned about the amount of strain you're seeing? It sounds like a tensile fatigue failure brought on by flexing of the rest of the car, not any of the 3 torque bar links. I would have the diagonals copied in steel.

Matt

Ok here is the fault we found, we most certain of it, the welded tabs are not inline with each other thus causing a twisting force/stress on the bar, thus it snapped! Got the bar welded back anf will have to reweld the tabs. :o

I won't tell you 'I told you so', but...I told you so haha :D

May the force be with me.:o