jhg41977

I am installing the rollbar I purchased and I have a few questions.

Car: 1996 993 C4S w/sunroof

It is an Autopower bolt in "Race roll bar", 4 pts with diagonal and cross bar. I have it in and bolted together to get the bolt holes marked. I cant get it to sit in there stable without it being slightly skewed to the line of the car. If I set all four feet such that the bar is stable and will not tilt, the upright by the B pillars are not aligned in the same position at the top near the standard seat belt mount. The drivers side is aligned nearly perfect with the front of the B pillar but the passenger side is approximately 1/2 inch towards the rear from the same point. If I align the tops with the B pillars, I cannot get the bar stable and will have to shim the floor post or teh wheel well post.

Is this normal? If so, which do you typically do, install in stable position or shim? If you shim, which is preferred, shim the bottom post to the floor or the rear post to the wheel well?

kjr914

Not an auto power, but a DAS bolt in (4 pts, 2 peice bar)... I had to use the car's scissor jack (and a couple of blocks of wood) to push 2 bar sections apart, then, at the same time, had to use a loop of nylon webbing to put my foot in to use all my weight to pull down on a section. THEN I could get the last of the 4 bolts in. It was a few night of cussing to get to this point.

I wonder if its the jig they build on, or is it the car variances that leads to these sorts of issues...

jhg41977

I guess that makes me feel sort of better?

k722070

same answer as keith, I used a jack to spread a das roll bar to fit.
so clear out the interior and get creative with jacks and pulleys.

jhg41977

When you say you used a jack to spread it, you mean jack up the car or you stuck a jack between the uprights and spread the uprights apart? Is this all a result of time and all cars experience this? Have you noticed any trouble after the bar was in for a while, such as the metal surrounding the mounting point tearing?

race911

First off I'll say I have NO experience with Autopower in the coil spring chassis. But back in the Olden Days when there really weren't any options for the torsion bar chassis, we'd loathe installing their bars/cages. But not like there were many options. Fit was less of an issue as they mounted to the floorboard, and not the sills. So the floorboard would deform, sometimes maybe up to an inch.

And please tell me they aren't mounting this 993 bar to the floor.

jhg41977

The two forward bars mount to the floor pan. The two rear bars mount to the wheel arch. Is there another style?

k722070

the das bar bolts to the seat belt mounts. in my case after getting the front bar in place with bolts loosely attached, the bar that connects to the rear seat belt holes was off by 1/4 inch or so. I used the car's jack, rags and pieces of wood to spread the bar into position and then bolt in place.
there is a thread with pics someplace on here about installing the das bar and wedging it into place.

jdistefa

had to shim my das bar
not surprising... you have a tub with small variances and aftermarket rollbars with presumably bigger variances
personally i would shim to fit to avoid preloading the bar and/or tub mounting points