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Marktat
10-21-2006, 04:55 PM
My 6-point roll bar is installed and Iím ready to mount my bolt in 5-point belts. My question is how to mount the shoulder harnesses to the cross bar. I noticed that some use a single bolt in the crossbar to fasten both shoulder harnesses, while others use two bolts, one for each shoulder. Iím leaning towards the two bolts as the single bolt method may cause the belts to rub too much against my neck. Any feedback appreciated regarding safety, comfort and NHRA legality of two bolts versus one bolt option.

Tig Man
10-22-2006, 05:55 AM
Weld 2 bungs through the bar about 6" apart exactly shoulder level, don't put them lower than your shoulder creating a pinch point! That's the way they are mounted in cup cars!

Mark

quadfather
10-22-2006, 03:32 PM
actualy they should be below. not at shoulder level . thats what the nhra rule book says as well as the seat belt mfg. if they are mounted at shoulder level , and you go upside down they can.t keep you you from droping down . i would mount them 4'' below your shoulders .tabs or bungs thru the bar are fine. just make sure to mount them at an angle that will pull rather than bend your bolts or tabs. also unless they go thru your seat .mount them only 3or4'' apart. if you put them too wide apart they will slip off your shoulders too the sides. i'm not trying to contradict the other reply. but this is how it's done at my shop. you can't mess around when it comes to safety. i found theese diagrams online from a seatbelt mfg. hope it helps.

Marktat
10-22-2006, 05:50 PM
Good info. Thanks guys.

Damn True
10-22-2006, 05:54 PM
From what I understand the wrap-around is the prefered method.

Marktat
10-23-2006, 04:45 AM
Not konwing much about belts, I would think bolt in would be prefered as the wrap around can slide from side to side?

Payton King
10-23-2006, 09:08 AM
than the shoulder in a hard front impact it would compress your spine?

hotroddr
10-23-2006, 11:34 AM
if they are mounted at shoulder level , and you go upside down they can.t keep you you from droping down
Isnt this the purpose of the lap belt? The lap/sub belt should keep you from dropping down if you are upside down. The shoulder harness should keep your upper body from going forward. At least this is how I understand it.

I would think a wraparound belt would be better than a bolt in because the loads are distributed more evenly. In a wraparound the load on the belt is distributed around the whole roll bar(3" by 1 1/2" round tube), whereas in a bolt in style, it is concentrated over the area of the bracket(3" by 3/16" or so)

David Pozzi
10-23-2006, 03:23 PM
For road racing with a HANS device, they want the shoulder harness level with the shoulders, or no more than 1" below them, and no more than 3 inches apart center to center. So - two 3" shoulder harness would be touching each other.

I'd carefully compare to what Nextel Cup is using as they have upgraded their specs most recently and spent a lot of money on research.

z65mm6
10-23-2006, 05:18 PM
Placement of your lap belt is just as important, if not more so than your shoulder harness. It's generally accepted among safety equipment manufacturers that your pelvis can withstand upwards of 5000lbs of force. Compare this to your abdominals which can withstand 300-600lbs of force before serious injury results. The idea here is to place your lap belt as low as you can. Ideally you should mount the belt to the frame or rollbar at a 45*angle and no more than a 60* angle. Around 5-6" behind your seatback would probably be fine

The purpose of your submarine belt is not to keep you from slidding forward, or out. It's to ensure your lap belt stays in it's proper location. It should be mounted 10* to the back of you as measured from your chest to buckle. So mounting it straight down would be a good start.

The angle of the shoulder straps should not exceed more than 2.5* below horizontal. Mounting at angle of more than 2.5* increases the risk of spinal compression should you encounter a serious crash.

David Pozzi and Quadfather both make good points about belt seperation and placement.

If you've never competed with a harness before, you will really enjoy the extra control it affords you. Have fun

nestockcar
11-10-2006, 09:45 AM
The track I used to race at (www.seekonkspeedway.com (http://www.seekonkspeedway.com)) had some good info in their rulebook, but the info is not there now. Either method (wraping or mounting) is fine from what I have been told. I would recommend the 2 bolt if using bolts.
It is key to get the lap belt right. Ideally is should be as Simpson (www.simpsonraceproducts.com (http://www.simpsonraceproducts.com)) describes: "Preferred mount is in a double shear with allowance for the bolt-in bracket to pivot and align toward the direction of the load". I attached their pictorials.

Damn True
11-10-2006, 12:03 PM
Good info Steve. Thanks!

Marktat
11-10-2006, 01:05 PM
I ended up welding 7/16 mounting anchors (from Chris Alston) straight through the cross bar spaced 4 inches apart. The inside edges of the belts are now about an inch apart at the cross bar. The only info I ever found on the spacing was at the Hans-Device website which stated “We recommend the center of the should belt anchors should be mounted such that the inner edges of the belt are no more than 3 inches (75 mm) apart.” Feels good and is not rubbing on my neck. Thanks everyone.

SicMonte
11-11-2006, 07:12 AM
well after reading this thread...i have a problem....my lap belt rests right on my belly button....not good. Here is my set up. I have a corbeau forza 2 seat with the simpson 3" cam lock harness...it is a 5 point but i only have the shoulder and lap belts installed. Im not sure how to mount the "crotch" belt b/c on the seat there is no provision for the belt. There is a big removable cushion on the seat, by the legs, where the hole would be...should be? I have the shoulder belts wrapped around the cross bar (which is removable...held in by big clevis pins)..and the lap belts are botled down and clipped into my existing lap belt holes in the floor. I will show you all pics when i get home from work today at 3:30 est.

How can i get my lap belts down more? i want to install the "crotch" belt to pull it down more...but im not sure about that cushion...aaahhhh. Who wants to come over and take a look at it?? anyone..anyone.

i will get pics asap.

this is the seat http://www.corbeau.com/products/forza2/forza2.shtml#

SicMonte
11-12-2006, 07:59 PM
anyone got some ideas??

SicMonte
11-16-2006, 09:07 PM
seriouslly....anyone...anything?

Rick Dorion
11-18-2006, 08:55 AM
Mine's the same way. Looks like I need that 5th belt to correctly position the lap belt. Hopefully there'll be input on the crotch belt mounting.

SicMonte
11-20-2006, 08:43 PM
i finally got some pics...let me know if you all think its an ok set up.

Rick Dorion
11-21-2006, 04:46 AM
Do your lap belts bolt to the stock bracket locations?

SicMonte
11-21-2006, 04:56 AM
yes

LS6 Tommy
12-20-2006, 08:40 PM
actualy they should be below. not at shoulder level . thats what the nhra rule book says as well as the seat belt mfg. if they are mounted at shoulder level , and you go upside down they can.t keep you you from droping down . i would mount them 4'' below your shoulders .

That NHRA book is either old, or WRONG. The FIA, SCCA, and IMSA require that you ALWAYS mount shoulder harnesses at, or slightly below shoulder height, usually not more than 2", NEVER on the floor. Most safety equipment manufacturers installation directions want you to mount the shoulder harnesses up to 30 degrees ABOVE the shoulder and not more than 5 degrees below. Of course, the farther back you mount the harnesses, the lower or higher you can go and still retain the proper angles. The shoulder harness is NOT to keep you in the seat when inverted, the lapbelt is. The shoulder harness is to keep you from moving forward during deceleration. Mounting the shoulder belts below shoulder height can and will cause spine damage from compression upon impact.

Tommy

SicMonte
12-28-2006, 01:06 PM
mmm...spine damage...doesnt that sound yummy?