6 Point Harness\Sub Belt Location

[Tim Kay]

Any SPF specific pics of 6 pt harness submarine belt mounts. Due to the SPF integrated seat support welded in place I am trying to find the correct location to bolt the submarine belts to the chassis and be relatively close to seat belt manufacturers recommendations.

The only option I see is to bolt through the light gauge floor plate with a backing plate but I'd rather not because a backing plate and bolt will reduce the chassis clearance and ultimately get banged about on gaters or speed bumps thereby deforming the light gauge steel flooring. IOW, bolts thru the floor affect clearance on the underside of the car and with only 4" inch clearance every bit counts.

I'm hoping to see if someone has fabricated a mount above the floor but below the seat support. There is a void area in that location that a mount may fit but I'm not sure this lines up the sub belts at the right angle suggested by the manufacturers.

Tim

 

[DaveM]

I've wondered the same thing Tim. Could sub straps be mounted on same bolts as lap belt? That's how formula cars do sub straps. Effectively you sit on the straps and they wrap up over your thighs. Problem then becomes how to cut hole in seat to accommodate other end of sub strap. For track day use I've considered not using the stock seat and foaming up a 2 piece seat to better accommodate sub strap. Foamed seat could have better side support too, but see that you have the narrow R seat anyway. I definitely would not mount through floor pan with plate.

 

[Tim Kay]

Bump, any suggestions?

 

[Terry Oxandale]

No photo (as yet), but I riveted the thicker backing plate onto the floor (not sure if this is applicable to your specific application) that distributed the load over a significant number of rivets through the floor and frame member under the thighs. The thinner plate (and heads) on the bottom resulted better ground clearance than had I used bolts. The top plate was even thicker with provisions to mount a split-block belt mounting strong enough to sufficiently meet the purpose of these belts. In my particular case, I'm sitting basically on the floor.

 

[Tim Kay]

Terry, when you get a chance post pics so I get a better idea of your description.

Thanks, Tim

 

[Terry Oxandale]

Here is what I have. These two belts go up a hole cut into the fiberglass seat bucket that sits on the surface of the .120" aluminum floor. It's better than a single strap. I'm planning on spreading them further apart in the future (to ensure testicular survival), but this is where I am today with minimal separation when tight (no man-binding).

 

[Tim Kay]

Terry,

Thanks for the clarification using pictures. Does the split block have clamping pressure on the belt fabric therefore securing the belt from moving or is it wrapped in a manner not to slip?

Looks to be functional and I like your installation but I'll have to give some thought as to it's application on an SPF chassis.

Anyone here have an SPF with the sub-belt installed?

Tim

 

[Terry Oxandale]

It can function without the blocks being tightened, but I chose to put a very slight pressure on the belt between the two blocks.

 

[Tim Kay]

So Terry,

there is another thinner plate on the underside of the chassis? The two plates sandwich the chassis floor?

 

[Bill Musarra]

I have the 6 point harness but in a DRB. The floor is much different and of no help to you. If you google 6point harness mounting there is a listing for "Images of the 6 point harness mounting" and every possible configuration of use. On my computer it is https://www.google.com/search?q=6+p...a5nY3NAhVGPCYKHaoxDDYQsAQIHA&biw=1190&bih=654

They show several configurations of the seat mounting hardware as a source of the mounting plate for the sub straps. There are other "pieces" that can be added to the frame of the seat for attaching. Must be hundreds of pictures(including some not meant for safety but for voyeurs). It should give you some ideas. If you have a seat made for 5-6 point harness then you should be able to extend the straps to the rear of the seat area and attach them to the bulkhead. Check them out.

Bill

 

[Tim Kay]

Thanks for that information Bill, the correct mounting positions are well documented as you point out.

I'm looking for examples of where, in fact, SPF guys are positioning their sub-belts. As Terry sited, and his example is similar to SPF, since we are technically sitting on the chassis floor and not in a "seat" the challenge is where to position the sub belt in the most optimum, correct and safest location knowing a compromise from 'ideal' is necessary.

Tim