NOSLO6

Folks,

I use one of the popular harness bars that attaches at the seat belt hanger bolts in my C6. This gives me an angle that's above, not below horizontal, and by quite a bit.

A tech inspector commented on it last year and I'm now looking at the install instructions that HANS provides and seeing a similar recommendation (below).

Do any of the harness bar manufacturer use lower mounting points? Other ideas?

Thanks.

RX-Ben

IIRC, the Brey-Krause will get near that in a C5 - I would imagine their C6 one is similar. AZ Speed and Marine is also good, but only for a C5 I think.

Bill Dearborn

Shark Bar does an excellent job. Bar is a couple inches lower than the OEM shoulder belt mounts and further behind which also helps change the angle. I went from a Hardbar to the Sharkbar because the Hardbar forced me to raise my seat as high as it could go to try and get the harness to fit over my HANS properly. With the Shark Bar I have the seat as low as it can go and the harness fits over my HANS properly.

Bill

stevensa

The BK bar in my C5z is at the perfect height for me when wearing my Defender HNR. I am 6'1" and use a Cobra Suzuka seat and Hardbar seat mounts. I have the seat about as low as it can go to give me plenty of headroom with my helmet on.

parsonsj

My 07 came with a harness bar... I think it's the BK. And it's too high, just as you've noticed.

I guess I'll look into the Shark Bar. Will it work with the same sail panels?

NOSLO6

Exactly what I'd hoped to learn-- thanks Bill.

VetteDrmr

Perhaps a stupid question: why do aftermarket automotive harness layouts always put the attach point below the shoulder? Is there no concern about spinal compression on a frontal impact situation?

FAA would fail any shoulder harness mounting that wasn't above the shoulder line in an aircraft, and if you look every automotive OE shoulder harness is above the shoulder line as well.

What am I missing?

parsonsj

I *think* the answer is that OE and the FAA don't prescribe a HANS device. For the HANS to work properly, there needs to be some wrap to keep it firmly seated on your shoulder.

Not too much, because then spinal compression is a concern. That's my story.

Joe Marko at HMS Motorsports would be the guy I'd ask to verify that.

VetteDrmr

Ok, I guess a HANS-compatible setup may have different requirements (my brain doesn't understand it but I can accept it), but how many HANS users out there are just going with a harness bar? And how many harness bar users (like me) are running HANS?

Thanks for the info, and have a good one,
Mike

ErnieN85

one here
i'd rather not use it just to find out how it will work

parsonsj

I guess you mean as opposed to a roll cage? That's a fair question. Count me in the HANS/harness bar crowd.

Scooter70

Me too.

Bill Dearborn

I had to change quarter panels when I swapped from the Hardbar to the Sharkbar.

I am attaching some pictures of the installation in my C6Z. The first picture shows my Ultrashield Seat resting on the top of the Hardbar rails. The seat is a 17 inch seat so it will not fit between the lower rails and still fit in the car. The second picture shows it installed in the car and how the belts come through the shoulder harness pass throughs. The third picture shows the setup from the rear clearly showing the bar and its relationship to the harness pass through holes. One other thing: Since the Sharkbar mounts further to the rear there is more room between the seat and the bar. This might help taller drivers that need to rotate the seat back rearwards to gain headroom. The Hardbar was several inches closer to the seat backs.




One way to think of the Hardbar is to imagine the bar being high enough that the shoulder harnesses would hit the tops of the pass throughs unless I raised the seat an inch and a half.

The seat back brace would also be angled downward instead of horizontal.

As for the comments about aircraft belts approved by the FAA OEM Automotive belts and 5 or 6 point race harness belts the style of the belt changes the way they are mounted. The aircraft belts and the OEM auto belts don't have sub belts to hold the lap belts in place so they depend on the shoulder belts letting the upper body swing forward over the lap belt slightly so the occupant doesn't submarine under the lap belt.

The sub belt in the race harness keeps the lap belt in place across the occupants pelvis and the shoulder harness is mounted lower to keep the upper body from flying around as much. The belts will stretch quite a bit. If you watch any of the test videos on the HMS site you can see how far they stretch. At one HPDE I attended Joe Marko had an in car video of Johnny Benson in a Busch (at the time) Car when it hit the outside wall of a track. Benson's upper body and the belts stretched far enough that it looked like his head was going to hit the right side of the car. Basically the harness keeps the occupant in the seat and the seat keeps the occupant in the car and away from all of the stuff trying to get at the occupant.

I think fighter jets mount their belts similar to the race style but don't know for sure. I know if it came time to eject I would want a belt system that held me firmly to the seat.

Bill

VetteDrmr

Thanks, folks, for the conversation. I learned a few things: 1. People *do* use HANS with harness bars, I assumed they were mainly in caged cars. 2. I didn't think about the lack of a sub belt in aircraft, that's quite true. 3. (and this one kinda seals the deal for me) I re-looked at the diagram and noticed that while the belts are slightly lower than the shoulder, the angle from the mount over the shoulder is still 90 degrees or more; I forgot to take seatback angle into consideration, so that should ease my concerns about spinal compression. Also, spinal compression is more of a concern in aviation due to the vertical loads imparted in a crash sequence.

FYI, ejection seat shoulder attach points are above the shoulder, but they're not really worried about high g decelerations. They also have active tensioners that fire at the initiation of the ejection sequence.

Have a good one,
Mike

JeremyGSU

Me three

fatbillybob

Don't forget you can weld to your harnessbar structures to change the belt path height and contain the belts laterally. Always think in 3D.