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View Full Version : 4 point harnesses, for the street?



Ripped
07-15-2011, 04:45 PM
I am upgrading the vintage lap belts, to a minimum 3 point seat belt, for driving safety.

Does anyone use a four point style harness for the street? Is is a PITA, to buckle up and drive in? Comfort level?

Our original 68 shelby came with that inertia reel 4pt system, but it was a PITA, we never used it.

Thoughts, suggestions appreciated.

4pt example; http://www.summitracing.com/parts/GRM-15-621/?rtype=10

FULMNTE
07-15-2011, 05:06 PM
Do you want to use your back seat?
Schroth has a 4-point harness with anti-dive which hooks to the stock seat belt points
http://www.schrothracing.com/store/Tuning/rallye/rallye-3

I have them in my Monte now and they work ok, but I will go back to the Morris 3 point seat belts again since my kids use the backseat often....
http://www.morrisclassicconcepts.com/index.htm

So, I will have a set of red Schroth Rallye-3 belts for sale soon...:)

724tim
07-15-2011, 05:14 PM
I use the RJS 5 point bolt in for my convertible.
http://www.bugsandbuggies.com/Parts.asp?CN=947&SN=76&GN=5

Vicinity
07-15-2011, 05:21 PM
I use the RJS 5 point bolt in for my convertible.

On the street?

JohnUlaszek
07-15-2011, 07:08 PM
I've been doing some research on this based on some things I have seen in the community.

Routing to the rear belt locations is pretty common, but often improperly implemented.

There have been pretty good discussion about this topic in the Safety and Tech forum, I am guessing the mods will bump you in there.

NOT A TA
07-15-2011, 07:37 PM
The 4 point Schroth belts mentioned have ASM design features that is different than traditional harnesses. This allows them to be used with the rear seat belt mounting location in some cars and also allows use without a rollbar with harness bar or separate harness bar. As John mentioned above there's several threads discussing them in general tech and safety. I used the Schroth 4 point with ASM system in my car for a few years and liked them very much, however there is limited movement if you snug them properly when compared to stock 3 points..

dropit69
07-15-2011, 08:31 PM
i have the schroth set up that uses the rear seat belts mounts and uses a modern style buckle easy to get in and out of..

tazzz25906112
07-17-2011, 05:25 PM
Agreed and the Schroth belts are DOT approved as well as race sanctioned I'm told....
I run them in all my early second gens where possible and love them...

JohnUlaszek
07-17-2011, 06:38 PM
The seats are a big factor when running this type of belt. The seat back must not fail under load and the seat must be of a design that allows it to essentially act as a harness bar to prevent compression of the spine. Schroth certifies applications/seats such as Subaru STI with actual testing of the seats in question -- not all seats are suitable for this application.

JonRB
08-05-2011, 05:49 PM
I used a 4-point on the street for a quite few years untill I reciently retired that car to storage and bought a Kia for reliability; Because of my lack of time for upkeep on that particular vehical.

That car was a Nissan, with a pretty extensive rollbar welded in it. It met the frame rails, subframe connectors, and rollbar out-riggers at some eleven points (all of which were seam welded as much as possible to the unibody). The belt I used was an RJS 5-point cam lock, and I typically removed the the submarine belt and clocked the cam mechanism my taking it apart and reassembling it differently.

First, I live in PA and the motor vehical code is kinda sketchy on that sort of thing, but just about every inspection guy here, who ever did my car, never had a problem with it, except for one, at one time - the belt was getting kind of dated, and it was time for me to replace it anyway. But any who, thay are not UV resistant, and being that I drove my car everyday, but never raced it, I would keep a belt well over the 1yr recommended cycle before a replacement. You'll never have to replace a factory belt as much as a harness - which will need to be replaced every year if you send your car through tech at a track.

After wrecking a few cars pretty good, and walking away with massive bruises from the factory belts. I feel the 3" harness, four belt harness is far superior than any factory system ever was. But I wouldn't mess to much without a solid mounting system. A harness really needs a cage or a rollbar.

I wouldn't mount one to the floor, unless you climbed under the floor and welded a load dispersing anchor plate under the floor, then looped the belt aroung the shoulder bar of a roll bar; which at that point you can see the logic in just going with a bar mount harness. Wouldn't do it without that shoulder bar welded in a roll bar really, really sturdily mounted in the car - as you can risk serious spine compression if the belt goes to the floor with out it.

I also see they have belt bars, that bolt to the original seat belt shoulder mounts - but I wouldn't trust that either, as shoulder harnesses mounted correctly should have have mounts pretty much inline with your spline (My shoulder harnesses uses the same mount for both belts over my shoulders). I'm not sure on the dynamic load capability of one of those belt bars. Best to have a real bar with a real shoulder bar intended to mount that harness - forget that back seat.

On the convenience of harness; Obviously some convenience is lost, so expect a few extra minutes every time you get in the car - The bad guy will be four blocks away before your buckled in. It obviously needs more time to get you belted in correctly; Go for the Cam-lock design. And the harness isn't going to recoil out of the way and you end up sitting on it alot and haveing to lean over to pull it out from under your butt. Then you have to make sure the belts aren't twisted because a shoulder harness that is twisted and then cinched tight is going to hurt. Then you have to snap three belts and locks as opposed to one. Then you have to cinch the belt tight - usually on three belts, but sometimes four if the lap becoumes miss-alighned, and it will from time to time. But mind you, a cinched 3", four point harness is one best feelings in the world. Think of it as a really loving hug from your car - one that can physically save your life. Also; you may need to mover your radio, and I suggest power door locks and windows, and if you need to get something out of the glove box while your driving, your not going to be able to reach it, as the harness will prevent your torso from moving so much as an inch.

I really miss that race seat, harness, and laser accurate cornering of that car. I'd drive it every day again if I could. Takeing saftey serious is way cooler than slouching in a seat and pumping some base. And if you have a bunch of roll bars and a harness visible on the street - people don't cut you off, tailgate, or in general mess with you as much in traffic; Almost as though your more prepared for a crash or something - I can't figure it out, but they tend to back off in traffic.

Saminator
08-06-2011, 05:39 AM
I have ridden in many cars with Schroth belts, and they are super comfortable. The shoulder straps a not as wide as most 4 point harnesses, so they don't cut into your neck.