Which torsion bar tube/mounts do I have?

[kiato4]

Hi all, on my 1973 911S which is a crazy mix of parts (964 bumpers, turbo flares, etc), I recently noticed that the car came with aluminum trailing arms and funky torsion bar tube mounts.

Does anyone know if the torsion tube has been replaced or just the trailing arm mounts? Maybe this is a turbo or G50 torsion tube?

Note that it has the RS/SC reinforcements which were welded on. I also think the mounting point looks further out, making me think either Turbo or G50. But I'm not sure which and what the proper course of action is now for my restoration.

[kiato4]

Turns out I have the 1978-89 turbo trailing arms on this car 93033151105 and 93033151205. So I still need to figure out what kind of torsion tube this is - 930 torsion tube, or just 930 trailing arm mounts welded on.

[Jerry L]

Check the weld quality, it might become obvious.

Regards

[kiato4]

Weld quality on the mounts themselves are much better than those horrible reinforcements.

What is also weird is that this car has a fuel pump bracket (left side of the pics) - is that the stock 1973 one or turbo one? They had different shapes, so if someone knows that would help me.

[gled49]

This is how my 930 tube was installed. Sleeves were made and install inside the tube, knocked in place and plug welded, as well as around seam. Additional 915 trans mounts were added behind 930 ones. The lower reinforcements on yours look stock, so was a whole tube installed like mine or just pick-ups points. Not G50.

[kiato4]

That is a very helpful picture.

The more I look at it, I don't see a sleeve and I think the fuel pump bracket is stock 1973. So I am thinking more and more that just the pickup points were welded on.

Unfortunately I only see camber boxes and RSR mounts for sale.

[gled49]

My tube was spliced in, the tubes, as spear parts were designed to be welded in as complete units, all the way through the longitudinal on each side where the spring plates would be fitted. Any signs the whole tube was installed?

[kiato4]

We sandblasted the car, and looks like the whole tube was indeed installed. Looks like a set of double welds where the tube meets the body for the spring plate on either side. I think the work was done in the early 1990s, I guess they sold the torsion tube whole then.

It looks also like I have both the 930 and the regular 911 transmission mounts.

What are my options to go back to narrow body trailing arm mounts? I think they are:
- Find new trailing arm mounts and weld them on existing torsion tube - needs rear seat sheet metal to be removed
- Find a whole new torsion bar - can be replaced without cutting out the rear seat?

Is there any way to drill the narrowbody trailing arm holes on the 930 mounts?

[kiato4]

The other question is - is it possible to install the narrowbody trailing arm mounts without cutting the rear seat area? Looks like it could be do-able.

[gled49]

Well, the tube is a late one, 84-> as the double trans mount was for Turbo and Turbo look. Factory mounting of the Turbo tube rotated it up 1 degree. I mounted mine flat 0 degree because I built a shim box to raise the arms at the front. It’s a shame to throw all that away. There isn’t any reason you can’t run the 930 tube and arms, except the wheel flange is more outboard, like an inch or more. So with stock fenders it would be like running a big wheel spacer, so no 7” Carrera wheels. Maybe 6” or 7R’s. Basically your current pickup points 2” farther out (back) than a 69-86 911. If you can get the car level, check the flat part of the pickup by the trans mounts and see if the tube was rotated up or is it level. You could re-drill the pickup holes 2” forward, and that would be original location approximately. My numbers are General you would need more exact measurements. Service manuals have all this info.