Torsion Bar Diameter

[kent olsen]

Can you measure the torsion bars diameter while still in the car?

Kent Olsen
72T upgraded 2.7

[boyt911sc]

Kent,

For the front torsion bars, NO. You have to pull out the front TB to measure them. For the rear, YES!!! But you have to re-index the spring plate. You can not measure the TB's without some sort on re-indexing the covers' splines setting. If you find a method, please let us know.

Tony

[911pcars]

Practically speaking, the torsion bars must be removed from the vehicle to measure the OD.

However, the mathematicians among us (not me) could probably calculate the spring rate of the factory torsion bars, then place a number of 100 lb. weights on the bumper and measure the ride height to determine the spring rate of the ones installed.

Sherwood

[randywebb]

the rear bars may have their dia. stamped on the end - if so you just need to pull enough stuff off to see that (maybe the spring plate)

[kent olsen]

Ok so much for that idea. My car is pretty light, under 2250lbs. I'm planning on building a 3.0L with my webers, headers and M&K 10lb muffler. With that in mind I was wondering if I need to increase the size of my rear TB. I don't know what is in there now but the car is really stiff and has very little body roll from pictures at the autox.

Two DE's at Sebring and the car was quicker in the turns than many of the other cars so it's possible the TB's have been upgraded. Guess I'll have to check when the engine comes out.

[barney911rs]

Kent, did you see my PM to you