>From: "Vijay Nuthulapaty" <vijay_at_sesd.cig.mot.com>
>Date: Wed, 7 Jan 1998 15:07:44 -0600
>Subject: E36 M3 - Harness question(s)..

>In lieu of the Simpson harness deal that Duane is working on, I wanted to do
>my homework in the kind of belt I would need. So I went by Northstar
Motorsport
>here in Barrington to see what can be done to my car.

Vijay, We're switching to Sparco belts as we have a similar deal on them from another supplier who wants to get the Sparco belts shown at the track. The Sparcos are FIA #1 rated (unlike the Simpsons) and cost slightly more. Again, anyone wanting in on this deal let me know and I'll get you the numbers and fitment options.

>>This is what John came up with as a configuration for my car (he is with the
>PCA
>and does not actively work with E36s, so if anyone could correct any of the
>assumptions here, it would help me a lot).

If you want an autocross belt or light use Driver's School then the 2" Schroth Ralleye 4's are perfect. They hook into the rear seat mounting points or you can get Neil M's clip in system that he designed for the rear seat attachment. IMHO, these type of belts are more to keep you firmly in the seat than to protect you from a high impact crash. They are great at what they are designed to do.

If you want a 3" belt for Club Racing or SCCA then its a whole different ballgame. Stepping up to these belts assumes you want maximum protection in a crash so the mounting is more restrictive. Personally, I think very strongly that a roll bar is in order if you are stepping up to 3" belts.

>1. The shoulder belts would go through between the seat and the head rest and
>bolt to the seat-belt bolts of the rear seats (the rear seat cushion needs to
>be removed for this purpose). This would create a very acute angle that the
>shoulder straps are bolted in. The alternative would be to drill a couple of
>holes in the rear deck and bolting the shoulder harnesses to them using eye
>bolts (I thought of using the holes of the rear headrests,
>but someone suggested otherwise. Any ideas on holes in the rear deck?).

Ideally, if using 3" Competition belts then you don't want that much stretch in the shoulder belt. You should install these to a roll bar / cage or at the very least a harness bar, NOT to the back deck or the rear seat mounting points. Angles are critical for design layout. The trick is to keep the belts short and mounted so there is no spinal compression in the event of a wreck.

>2. The outboard lap belt would loop around the seat mount, and so would the
>outboard submarine belt.

Look and tie off where?

>3. He couldn't figure out a way to mount the inward lap and submarine
belt. He

>suggested drilling a hole in the tunnel (where is that exactly?) and putting
>an eye bolt in it and bolting both the submarine belt and the lap belt to it.
>The submarine belts would go under the legs and not under the seat. This is
>why he suggested a 6-pt instead of a 5-pt because the stock seats have no
hole
>in them to accomodate the single submarine belt.

Bob Stommel and I have been swapping a lotta e-mails on this lately. Mounting points are ultimately determined by what type of events you want to run as each had different requirements. What is legal for BMWCCA Club Racing will not pass an SCCA Tech Inspection. However, if you are racing then you must have a roll bar as a minimum with BMWCCA and a cage with SCCA, so that's a factor, too.

For least invasive mounting you can have a large, thick adaptor plate made for the inboard lap belt mounting point and simply slip it under the existing seat rail. You will need a longer seat mounting bolt. Then you mount your eyebolt to the adaptor plate.

If you go 5 pt or 6 pt sub belt here are two options to mount. Either way you have to cut a slit into the bottom of the moveable thigh bolster to run a belt through it, then sew up the edges around the cut. With a 5 pt, you can fabricate a square steel bar to run between the front mounting points, again UNDER the existing seat rails. Then you simply mount the eyebolt in the middle of the rail. With 6 points you can tie off direct to the front mounting bolts. Be aware that a dual sub (6 point), improperly postioned, can crush your leg's main arteries in a crash. Careful!

For the outboard mount on the lap belt, you can use the existing stock belt location on the pillar.

All those adaptor plates will raise your seat height a bit, probably an inch.

Bob S., wanna add anything to this?

Duane Collie
RM3DR1 UUC
National Capital Chapter

P.S. Since you are getting belts, don't forget a helmet collar support. And get a good one that's not mushy. No since snapping your neck when you crash!