e30 roll bar project

[Digitalwave]

Hey, it's the only reason I'm here.

[PeaveyBassist]

I like to hear TJ speak.

Will

[Hatchman]

I dont know shit about roll bars...

but I do know this is a funny picture

[GaryE30]

um... ha ha ?



I guess I missed it.

[Lance Racing]

"I think I might have some pieces of FIA-rated foam left over that I could kick down to mitgate the issue a bit. Looking in the PCA CGR's, 3.2.f Any portion of a roll bar/cage assembly within 12 inches of a driver's or passenger's head shall be padded."

I believe that PCA 12" rule is assumed that the occupants are wearing helmets. For an unprotected head, that stuff will only protect the head from minor "bonks" when getting in and out of the car, say from the high horizontal bar that goes from the A to the B pillar (not in this car in question obviosly).

If this car ever goes to the track for DEs, then this is certainly better than nothing. In the past month I've seen two BMWs go on their roofs from fluids on the track, where the driver had no chance to save the car. One roll over was at lower speeds in a street car with no cage, and the roof did crush in a bit, the occupants were lucky to be OK. The second roll over was at much higher speeds, and luckily the BMW had a full cage as it went end over end. The cars were write-offs.

For a street car, I would have at least run the cross member the other direction. As most cars see just a single occupant, it puts that hard diagonal object behind the passenger's head, rather than the driver.

On rear impacts, BMW seats are known to break down at the hinge, so the body lays down in the car. This provides more room between the driver and the roof, if the roof were starting to compress down. You've solved the roof crushing down, but still have a stock seat. You might consider a fixed Sparco or other seat, which will keep you upright and hopefully away from that diagonal bar.

You would be amazed at how much the body flies around the car in a wreck. And not just the arms/legs, but even the torso and head. Even 5-point racing belts are designed to allow a stretch of around 8 inches to help with deceleration. Once racing belts have been stretched, they are to be thrown out.

My qualifications are as a long time BMW instructor, as well as racing a BMW for 8 years. I've done a lot of reading and research on cabin safety.

cheers,

Lance Richert
#135 Pro-3

[IS]

Thanks for the comment Lance. An OMP or similar seat is in the works. Going to fixed back seats eventually was my plan.

[Lance Racing]

You'll love the seat. A little more of a pain to get in and out of, but you feel SO much more connected with the car with a fixed seat that does not have so much padding.

If you go to aftermarket belts, be sure to follow the install directions closely. Especially the rec. angles for use of the belts. Here is one page on Schroth 4-points. I use Schroth 5-points on the race car. I'm warry of 4-point belts because the crotch strap is what keep the lap belts firmly on the pelvis bone. Without the crotch strap the laps belts can tend to snug up and in the event of a crash, the belts do not push against the pelvis bone, but soft tissues instead, which is not good.

http://www.soloracer.com/harnschrothfaq.html

no affiliation...

[nkell09]

Informative post Lance, thanks for the info!