Seats and 4pt Harness (1 Viewer)

[drohweder]

So I need new buckets and harnesses. Is is ok to use a racing type seat (I'm thinking a late model celica or rsx seat) and bolt the shoulder harness behind it to the floor?

I would like to avoid having to run the harness back and up to the roll bar. What do you think? Is this an unsafe idea. Anything is better than the lap belts I've got now.

 

[Cruiserdrew]

I have a cross bar welded to the roll cage just below the top of the seat. This carries the upper harness. I attached the 5th mounting point to the bottom of the seat with HD hardware. It's a very solid fit, though fortunately I have not had to test it in an accident. I used the Simpson heavy duty (3 inch webbing racing harness) and it holds you so tight that you need to unclip to look behind you. You are welcome to come by anytime and check it out.

 

[Devils Paw 80]

I would like to avoid having to run the harness back and up to the roll bar.

Why? Just curious, since I bought some aftermarket shoulder harness belts from CCOT that are mounted this way. I've got the stock seats with the two inch extention brackets. Man, those extra inches make a world of difference! Don't see how anyone over 6' could stand the lack of legroom in a stock 40.

 

[Devils Paw 80]

Oh, I see. 4pt. harness. Never mind!

 

[drohweder]

I know many people have welded cross bars. Is it safe to not do that and wrap the shoulder harness over the top of the seat and mount it down on the floor behind the seat?

 

[Desertdave]

I know many people have welded cross bars. Is it safe to not do that and wrap the shoulder harness over the top of the seat and mount it down on the floor behind the seat?

Everything I have seen or read on the subject says NO to that type of installation of the shoulder harness. I think in a collision the intent is to stop you from going forward, and with that wrong type of install you will still be able to go forward, while also breaking the seat back and compressing your spine. Or so I've read. I worried about this myself, once, when I bought my 'Cruiser and the PO had the belts installed that way. I welded in a harness bar across the back. You can either attach the shoulder harness to the harness bar, or down to the floor after passing over the harness bar. Either way will direct the forces on the driver in the direction desired.

 

[Cruiserdrew]

Dan-One of the PMC members, Mike Dremmen, is a welder and welded in a cross bar of DOM tubing for me for almost nothing. He also made me a killer skid plate that has taken the entire weight of the truck on the Big Sluice last year. I'll try and find his # but he is listed in the PMC newsletter.

 

[sherwood]

'Dug out an old Tony Bingelis sport aircraft construction handbook. They recommend the seat belt (lap belt) to be at a 45 degree angle and the shoulder harness should be attached at a point level with the shoulders. Here, I guess, you would need to consider the range of height of shoulders for various drivers that might use the LC...... maybe weighted toward your own shoulder height. Your call.

NTSB survey showed that 80 percent of front seat occupants that survived a crash .... wearing lap belts only... suffered head injuries.

I will go with DesertDave....
"I welded in a harness bar across the back. You can either attach the shoulder harness to the harness bar, or down to the floor after passing over the harness bar. Either way will direct the forces on the driver in the direction desired."

I would add to that to be sure there is some type of "loom" or something to keep the belts from moving/spreading on the harness bar if the ends of the belts are going to be attached to floor or something else of appreciable distance from your shoulders.

john

 

[usmcruiser]

Check out this tread.

https://forum.ih8mud.com/showthread.php?t=24191&highlight=harness

 

[helocat]

I think in a collision the intent is to stop you from going forward, and with that wrong type of install you will still be able to go forward, while also breaking the seat back and compressing your spine.

Dead on point. You can run the belts anchored to the floor up and over a shoulder harness bar, but you then need to keep an eye on abrasion. Key thing to keep in mind when you put in a harness bar is to anchor them to bolt tabs welded to the bar, DO NOT drill holes in the cross bar to bolt the anchor points too. Not pimping MT gear here but the cross bars MT sells now comes with 4 weld on 3/16” tabs for this reason. I have seen to many install photos where they ran bolts through the tube.

If you don’t like the idea of a seat belt cross bar in the B pillar, look at standard three point belts. The 4-5 point harnesses are great…if you ware them. I found running the 4 points I rarely put on the shoulder harness. Only time I did use them was HW driving. (And to their credit I did have them on when I street rolled back in 92’, they work great!) If you look at shots of people sport wheeling that have the harness they rarely have the shoulders on. You can not look out the side or behind you easily. And in some occasions you can not reach things on the dash, lights ignition on the early models. (When I rolled my 67’ the motor was running upside down for a few seconds since I could not shut it off! Spooky noise!)

For my trail rig I have the original 79’ 3 points in there. They work great, lock up when they should yet let me lean out and look around. Again 4-5 points are great belts as long as you ware them. I am not saying don’t get 4-5 point harness most people know I promote safety. It’s just that a 3 point on a retract is much safer than a 5 point being warn as a lap belt only. I still have two brand new 3” 4 point H style (works best with the cross bar) harness in boxes. I just don’t think I will ever put them in. Maybe a buggy or something…

Mark

 

[drohweder]

Thanks guys for the input. Safety is my primary concern so I want to do it right. I have a set of used mini-truck shoulder belts that I could install but I'd have to weld a connection somehow to the B pillar of the roll bar.

Now, what about those racing seats that have cut outs for he shoulder belts to pass through? Achoring to the floor then should be ok????

Guess it all depends on the seat that I end up getting. Seems a seat designed to use 4pt harnesses (ones with a slot for them) could stand up to the force if encountered. Thanks.

 

[Cruiserdrew]

I'm not sure if the floor panels are strong enough for the mount. The info with the Simpson harnesses said specifically not to bolt to the floorboards, though with a large backing plate it might be OK. The cross bar on the cage is simple and effective-are you sure you don't want to just do that?