Odd Q.
Does anyone have an E30 with a roll bar or cage in it? I have an old 1G DSM bolt in 6 point cage with the rear legs missing. I was planning on selling it cheap, but it occurred to me that the main hoop with diagonal and harness bar may be very very close to an E30 main hoop if I fabbed some new rear stays.
An E30 is necessarily in my future as part of the GRM trifecta of cars so I must own one at some point.
What I’m looking for is:
‘A’ - The height of the cage from the feet to the top.
‘B’ - The outside dimension of overall width
‘C’ - The distance from either the floor, or the top bar to the harness bar.
Thx
ddavidv
UberDork
4/27/12 11:05 p.m.
I can help you out, but it will be after the weekend until I can post back with measurements.
A couple questions
- Are you removing the sunroof cassette to get the bar tight to the roof?
- 2 dr or 4 dr?
- Does it need to fit into the car or is it going to be custom built IN the car?
The height of the harness bar can/should be relevant to your own shoulder height. Most belts require a +30 to -5 deg range and no more than 4" below to avoid spinal compression in an impact. I'm 5' 10" and I can tell you where mine is but seat mounts, angle and so on will make it more of a general reference point. The best way to do it if you are caging your own car is to mount the seat and make measurments relative to it.
EDIT:
(A) The height of the top of the hoop from that point is 44" with no sunroof and the bar pressing against the roof skin.
(B) Is 51.5" and is tight to the sills with 3/16" reinforcement plates tied in.
(C) MEASURED FROM THE FLOOR at the foot to the top of harness bar is 25.75"
Oh... and make sure the diagonal bar is straight thru and the harness bar is either cut to mate to it or run behind. If you do it the other way (cutting the diag.) is is not SCCA, NASA or BMW legal for racing.
The car I'm going to look at a 4 door 325e with a sun roof. I would intent on keeping the headliner and as much interior as possible. This would only be for track days, no racing or time trials, just some added safety.
This might just work. The cage is basically the same width, but a little shorter with the cross bar a little higher. If I get the car I will be keeping the headliner and sunroof so I’ll have a chance to cut off the existing pads and weld new boxes to mount it on at just the right height to suit. The only negative I see is there is more tumble home on the DSM so the upper part of the bar will be a little further in than ideal, but still outside my head. As this would be a track day car I think I could make it work, certainly better than no bar.
