Seat Belts

[stu]

Many years back I installed three point seat belts in my Tiger’s factory mounts. I have always felt that the lap belt was positioned a bit too high on my abdomen to be effective if anything unfortunate happened. The explanations I’ve heard say that the lap belt should really be low enough so that it transfers all of the force of a crash to your pelvis, rather than the soft internal organs above.

The webbing in my seat belts was old when I got them, so I finally decided it was time for replacements. Maybe I was inspired by all the controversy about Earnhardt’s belts after his accident, but I decided to do some research before any replacing got done. As with most of my Sunbeam projects, I get around to them eventually and eventually turned out to be this spring.

My main concern was the location of the floor mounting points, and the resulting angle of the belts as they leave your lap. I checked numerous internet sources, belt manufacturers, even some racer sites such as Simpson. Those that provided any numerical info all recommended a fairly high angle for the lap belt, over 45 degrees from horizontal. Recently produced cars all have belts that must comply with a bookfull of NHTSA standards, so they should give a decent indication of what the current standards are. With the seats adjusted for me (I’m of below average height, so that’s fairly far forward on most cars), I measured the angle of the belts in our daily drivers. The results were: Subaru: 55 degrees, Explorer: 42 degrees, Sable: 45 degrees, Mystique: 58 degrees. The Mystique was the most interesting, since the lap belts are mounted to the seat and not affected by seat position. The Tiger? 36 degrees.

Based on this data, it is my opinion that the Tiger’s belts are not ideally positioned for shorter people. Taller folks can draw their own conclusions.

I purchased a new set of 3 point belts from Moss Motors, which came with threaded “eye” type mounts. I located a point on the floor, about 8 inches ahead of the original mounts, that would produce around a 60 degree angle, and drilled to install the new mounts. CAUTION: The passenger side inner mount is very close to the brake and fuel lines, and the tabs that hold them in place. I drilled the hole for that mount a couple inches further aft, and really close to the tunnel, to clear the tabs. I plan to purchase another set of eye bolts to be mounted in the stock mounts, should anyone really tall ever drive my car. The Moss belts can easily be transferred from one set of eyes to the other.

I put some photos of my installation at the following address on Aug 2, and I’ll leave them there for a while:

http://www.pbase.com/sb_photos/belts

In the photo the difference between the angles of the old and new belts is obvious. The new belts feel like they are positioned much like those in our regular cars.

[krisha]

quote :

Many years back I installed three point seat belt in my Tiger’s factory mounts. I have always felt that the lap belt was positioned a bit too high on my abdomen to be effective if anything unfortunate happened. The explanations I’ve heard say that the lap belt should really be low enough so that it transfers all of the force of a crash to your pelvis, rather than the soft internal organs above.

wow, there’s an effect in the body organ how the belt positioned. well very interesting.. thanks for sharing that thing..

[Author]

Posts