I am in the process of installing a harness for use in performance driving education events on the track. I already have a lower seat and higher rollbar (thanks Aaron ), and now need to hold myself in position better.

A 5 or 6 point harness will work in my car (leaning towards a 6 point) and I have the lower mounting points figured out for the lap belt and the anti-submarine belt(s), but need some help with the upper points for the shoulder belts. I currently have hardware that allows them to attach directly behind the seat. My concern is that I'm tall, and would need to route the harness up and over the top of the seat. My torso is too long to use the holes in the seat (Sparco Roadster), and I wanted to make sure that I was doing a safe install. According to the Sparco website, the shoulder belt mounts should be placed such that there is less than a 45 deg. angle up to your shoulder. Given the hardware that I have now, it would be closer to 70 degrees. Any suggestions?

 

Hi. The shoulder belts should be as close to horizontal as possible. You should use a harness bar, or much better, a roll bar to mount them on. You could, theoretically, mount them to the stock roll hoop. One other thing you didn't mention: chest strap. If the straps aren't going through the holes in the seatback, you need a chest strap to keep the straps from seperating, and allowing your shoulders to slip right through them, in a crash. It doesn't matter how much wider you think your shoulders are at 60 gees. Good luck!

 

CoralDoc,
I've got the bitter-bar installed and have been waiting patiently for Aaron's shoulder-mount plate so that I can securely attach my 4-pt. Schroth harness. I'm using the stock seat and have mounted the drivers left harness to the roll-bar itself (perfect geometry for my height) and have mounted the right harness to the stock mounting point (not even close to ideal). It's all I have to work with until I figure something else out (or until I finally get word on the status of the harness plate that shipped to me over a month ago).

Having the harnesses mounted horizontally (measured from top of shoulder) is ideal in a frontal impact, but not in a rollover. If I remember correctly, 10 deg to 45 deg is the recommended angle the harnesses should be mounted.

Whatever harness you get, make sure you get the pull-up style lap belts and not the pull-down. The pull-down is all but impossible to adjust.

I'm very interested in how you've figured out the lower mounting points for the lap belt and the anti-sub belts. Can you elaborate?

 

What rollbars do you guys have...custom made?

 

Aaron Bitterman's Bitterbar.

 

Oh yeah. I remember when that first came out and he was asking for suggestions I suggested that he add a way for harnesses to attach easily. He pretty much told me that any idiot would be smart enough to do that and that it should be obvious to me that it was part of his design to do so. Something like, "Do you really think that I'd spend all this time designing this and not allow for a harness to be attached?" That's all it takes to turn away one customer. <still bitter>

 

It's an awesome bar, but if I were to attach both shoulder mounts to it the right shoulder would wrap too far around to the left side and who knows what would happen in an accident.

 

Wesmaster,
Wow, I don't remember being a pompous A-hole to anyone recently. Especially someone in Texas! Probably krazik or fluxen responded to a post for me and you got us mixed up. But I guess I'm an idiot since I never figured it out either until I had my builder design harness mounts for me. If it was me, sorry I came off that way.

Josh,
Is the 70 degrees from the top of your shoulders or going over the top of the seat? If it's going over the top of the seat, maybe you could widen the existing openings in the seat higher up, or cut new ones? The real question is whether it's from your shoulders or the seat, right? If the angle from your shoulders is OK, it's fixable, if not then you better return that harness mount!! Or send it to Wesmaster .

dt

 

[QUOTE]Originally posted by desert tortoise
[B]Wesmaster,
Wow, I don't remember being a pompous A-hole to anyone recently.

 

Thanks for all of the suggestions - here's what I've learned from some local shops:
If you are expecting head-on impacts, shoulder mounts within 10 degrees of horizontal are most effective. In a rollover, having up to a 45 degree angle from your shoulder to the mount is more effective. I don't plan on either, but since it's an open car, I'll opt for a greater angle. Furthermore, the Sparco website recommends the former and the Simpson website recommends the latter. When I sit in the Sparco Roadster seat, my shoulders are even with the seat's "shoulders", so I don't think I can go any other way than over the whole seat.

I ordered a harness from a local BMW race shop and they have offered to help with the fit. One option is to tie into the rollbar close to where the guide for the OEM belt is clamped on, but the right shoulder mount is problematical. I am hanging on to the harness mount for now, since it may still work.

BTW, I've had nothing but excellent dealings with Aaron, and I'm completely happy with the functionality of the rollbar he helped design and now distributes.