blade7

I see a company is selling a 'rear support truss', that mounts between the C pillars, above the rear seat back. Is a bar mounted there, going to make much difference to the shells rigidity?

931guru

No.

spencang

I made a custom one and connected it to where my rear seat bolts were. I noticed the difference immediately. A friend of mine who was following me on a twisty road kept commenting on how flat my car was too.

spencang

I actually made this about 3 years ago...

blade7

That's what I'm thinking about doing, got some suitable parts in my garage. The one being sold mounts to the seat belt fixings, which seems less effective to me.

GPA951s

From a practical point of view i dont see how this helps in any way, there is really no “ side load” there.. just the shock mounts.. sure the torsion plates are close but the are for the vertical load..
i think if it made any difference the turbo cup cars would of had something like this. The engineers felt compelled to build in a front strut tie bar right into the chassis, but they overlooked this?

blade7

The Cup cars had a proper roll cage, so didn't need a bolt in bar there. It seems to be a known thing on some other makes though, so as it would cost me next to nothing I'll give it a try. I wouldn't pay $250 for one, or fit it between the seat belt mounts though.

968to986

I have a Weltmeister harness bar on my car, but I’m not sure I noticed any difference in rigidity. People think it looks cool though, so there’s that.

V2Rocket

In 2006 or so I essentially made one of these on my car.
I got some ~5/8" OD rubber hose and cut 3/4" long pieces and put those on the "pegs" that the rear seatback would latch do. Then I spanned the two posts with a piece of steel pipe ~7/8" OD and 5/8" ID (have to take the seat pegs out of the car, install the pipe between them, re-bolt the pegs to the car and then adjust the pipe a little). The pipe compresses the rubber hose "bushings" and fits snug.

My purpose was just to keep objects in the trunk from sliding forwards since I had removed the rear seat.

blade7

How is that mounted to the shell?

blade7

What do the seat 'pegs' bolt into in the shell? I just loosened one, and it seems to bolt into some kind of adjustable captive nut, behind the panel. I was concerned that this nut might drop down if I removed the peg.

V2Rocket

It is a captive nut plate but it won't fall down when loosened,

blade7

Thanks. I found a pic of a stripped out shell, and that explained it.

Droops83

If you want to go a step further, a bolt-in roll cage is a thing. I installed an Autopower 1/2 cage in my '86 951 about a dozen years ago, and the most noticeable effect was any hint of hatch squeaking was immediately eliminated due to the localized increase in torsional rigidity. There are articles here and elsewhere about adjusting the hatch pins---the Only944.com hatch pin inserts are a great product.

blade7

Don't want to go to a cage on a road car.