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Date: Fri, 29 Jan 1999 20:02:55 -0600
From: Scott Blazey <>
Subject: Track Safety Equipment

This will be a little long, but those of you who know me also know that I often suffer from diarrhea of the keyboard.

First of all, thanks to anyone and everyone for setting up this new digest. For a lot of years I found the other digest fun and useful, but it was getting to be like using a port-a-potty that was long overdue for service.

Duane is right about any safety equipment being a compromise. As a compromise, it's up to you to decide what and how much you give up on the street for more safety on the track.

Rollbars are great for rollover protection, a little bit of side protection (depending on the angle of the strike), stiffening the chassis, and hanging your shoulder harnesses. All good for the track. So what do you give up on the street? Room for your head and other body parts to move around without hitting something. You must understand that in a collision on the street, your unhelmeted head and arms are much closer to some mild steel, even when the steel is padded. And so is your passenger's head. Don't even think about putting anyone in the back seat of a rollbar'd car, unless you can stand the emotional trauma and punitive damages.

Four-point harnesses are great for holding you in the proper position on the track. Don't remove your stock belts because camlocking up the trick comp harness every time you drive to the post office gets old after about, oh, one time.

The 5th or 6th (crotch) strap(s) do indeed help keep you from submarining. But perhaps more importantly, they hold the lap belt down low around your hips when you cinch up the shoulder straps, and in a collision, will help prevent the lap belt from riding up under your rib cage and rearranging your internal organs. Be warned, however, that the crotch straps need to proceed directly from the buckle down to the attach point, with perhaps a 5 degree forward cant allowed; otherwise, the strap(s) will not perform its required function correctly. If you're looping a crotch strap over the front of your stock seat, you are setting yourself up for potentially more injuries that if you had no strap. Another good reason to get a racing seat.

At Gateway Tech last year, Joe Marko discussed the results of a study that showed that the safest combination was a 2 inch lap belt and 3 inch shoulder straps. If I remember his explanation correctly (an unlikely probability), the 2 inch belt was more likely to be positioned correctly, given the average person's skeletal structure. A 3 inch lap belt was more likely to be positioned in such a way as to slide up toward the abdomen upon impact. However, this combination is almost never seen because most, if not all, racing sanctioning bodies mandate 3 inch lap belts, figuring bigger is better and stronger and a wider belt must spread out the load more.

Attaching seat harnesses by fitting the ends between the seat rails and car floor is not a good idea. At the very least, if you do this, you should use longer bolts of the appropriate grade, but keep in mind that the seat rails are no longer resting flush on the floor as designed, and now only the bolt is keeping the rail from moving, not the combination of bolt and friction from a tight, surface-to-surface pressure. However you mount any safety equipment, try to make sure that your method does not reduce the safety that BMW engineers built into the car.

Naturally, everything I've said about safety equipment and installation can be overridden by Rule #7 (see below).

That should do it for now. You can rinse and spit.


(Rule #7. Any modification is authorized if it looks cool.)

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