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Posted by: McMark Mar 26 2014, 09:14 PM

Working on a track bound 914/6 and we have some confusion about rules I'm hoping ya'll can shed some light on the issue.

We're looking to install a 5 or 6 point harness and need to know what sorts of considerations we need to make for installation. The car is almost ready for paint, so we need to finalize all the backing plates, etc. I have already planned on using welded backing plates and nuts for attachment to the body. The biggest question is about a 'harness bar' for routing the harness to the correct height. There used to be a product that mounted on the upper seat belt mounting points. Would this style bar work for keeping the harness above shoulder level?

Posted by: ThePaintedMan Mar 26 2014, 10:25 PM

Mark, I know some of the other more knowledgeable guys will chime in, but I've been tutoring under the chief PCA tech guy here in our region for the past year.

It is my understanding that in SCCA and PCA, any harnesses must either be attached to a dedicated roll cage or use large washers which mount on the firewall. Schroth and other manufacturers usually sell them as a kit.

The *biggest* question with harnesses now days pertains to the installed angle behind the driver. The harnesses should go over the shoulders and proceed between 0 and 15 degrees downward angle to prevent the driver from suffering spinal compression in a crash. Depending on the seat installed in the car in question, this may or may not be feasible with the harness bar.

This angle is even more important when using a HANS device as I understand it - the HANS relies on the angle to function as intended.

Of course this depends on the sanctioning body, but I would imagine that PCA and SCCA are some of the most stringent and well though out rules when it comes to safety.

Posted by: Matt Romanowski Mar 27 2014, 05:58 AM

Short answer is that you won't get them set up right if you use a bar like that. Better off putting a cage bar at shoulder level behind the seat or if no cage, then right to the firewall with appropriate backer plates.

Here is the Scroth guide to mounting harnesses http://www.schrothracing.com/sdocs/2009_Competition_Instructions.pdf

Posted by: Randal Mar 27 2014, 09:27 AM

+1

The important thing is to read the rules and make sure the angle (or height) of the rear harness bar is right.

Because I'm over 6' and wanted the seat way back we had to bend a bar that attached to the cage hoop on one side and a plate on the inside hump. It more or less follows the contour of the (cabin) firewall. You can't see the entire bar, but I can take other pictures if you want.

Posted by: McMark Mar 27 2014, 10:18 AM

Randal, that picture makes perfect sense to me.

I'm going to edit my first post because I realize now that I was a little unclear. I have already planned on using welded backing plates and nuts for attachment.

So if we were to use the harness bar I pictured in my first post (or something like it) simply to route the harness at the correct height, then that's acceptable.

Posted by: Randal Mar 27 2014, 11:27 AM

Been a while since we noodled this, but the big issue was the angle of the straps going to the shoulder. The magic point, where the belt shoulder angle is within the SCCA specs is where you weld the tube.

The thing to note in the rules is that the seat holes, like in the Kirkey seat, are not guides, the angle is. So make sure the driver sits in the car, with the straps on and that you locate the bar within that 20% angle.

Posted by: ThePaintedMan Mar 27 2014, 02:53 PM

with what they said.

To answer your other question, the harness bar can be used to route the harnesses but only if the angle of the belts coming over the driver and through the seat is downward at 0-20 degrees. I would think that would be too high for most applications though.

As long as the harnesses are hard bolted into the firewall it shouldn't make a difference, but I also know whenever they are attached to a bar they need to be secured with some kind of spacer to keep them from migrating in the case of an accident. I think that's what they're referring to with the guides above. That's about it.

Posted by: Racer Chris Mar 27 2014, 07:14 PM

The harness bar doesn't meet the GCR specifications for SCCA road racing.

Posted by: Trekkor Apr 5 2014, 11:42 PM

Stop by next week and look at my set-up.
The Schroth diagram is about the best.

Posted by: Trekkor Apr 5 2014, 11:48 PM

http://s944.photobucket.com/user/trekkor/media/car%20photo%20dump/seating.gif.html

This may help