bauerjab

Do the properties of torsion bars change over time. And if so, how so? Do 12 yearl old torsion bars need to be replaced? The car is for racing.

Thanks

Noel

I image that the life span is similar to springs, in that they will begin to sag and loose free-height but the spring rate should remain the same. The real issue is the condition of the bars. If there is any rust on them, then you risk breakage which would be bad. I'm assuming that you have updated (Larger than stock) bars since the car is used for racing, therefore they are probably in decent shape. The real issue is usually with the front ones. If you haven't repaced the front a-arm bushings, then the bars tend to rub on the a-arm tube (Larger aftermarket bars are even worse) and rust start to form where the paint is rubbed off.

Steve Weiner-Rennsport Systems

Bauerjab:

Generally speaking, torsion bars do not sag unless they have been improperly heat-treated. They can and will break if the surface develops any stress raisers from either corrosion or surface damage.

What does change over time is the car's ride height caused by sagging, aged rubber bushings and that can corrected with the installation of aftermarket ones.

FWIW,..........A good, well made spring (coil or T-bar) will NOT sag if its manufactured properly and there are some poorly made ones out there,.....

Noel

Interesting Steve. Hopefully, Sway-Away are considered to be "Well made," as that is what I have on my SC.