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So how about a sacrificial nylon sleeve over the belts? It could be replaced every two years for $40 to keep it looking pretty, or perhaps longer since it will still be a UV blocker even if the strength of the sleeve (which is not its purpose) is degraded.

I'm assuming here that UV is the big belt killer. Any idea if that is true? I would be surprised to learn that the nylon is not chemically stable or something.

For racing applications, there could be mechanical factors working against the belts, too. Detroit's belts never see any notable strain before their starring moment. With inertia reels, there is essentially no tension on the belt. A race driver has hard points and set adustments, generally set as tight as possible. Then they make a lot of 1G accelerations in a high NVH, dirty environment. For a given driver, one point on the belt may hit the same 1/8" thick hard point for the life of the belt, as opposed to 2/3 of the hard points in a factory car that move every time you turn the key.

A sleeve might also keep the belt cleaner, which will reduce wear on the belt.

-dave "what do i know" hempy

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I like all of your logic Dave ..... if you could just prove it to all of the sanctioning bodies and have them change their regulations we'll be all set.

Thanks in advance!

IIRC nylon stretches a bunch more in a crash, which make poly preferrable IMHO in a car that doesn't have airbags nor belt tensioners, this could be the difference between leaving your nose and teeth on the steering wheel or not...

Oh, and OEM belts definitely age.
I replaced the ones on my truck because they were really dry and I didn't trust the webbing to hold me.

Moti

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Another factor to consider when using donor vehicle seat belts:

Factory belts for airbag cars actually have folds sewn in, designed to rip and give during an accident, letting the bag do more of the work and decreasing the peak g forces on the internal organs.

Some stretching is good if you design for it.

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As one with personal experience with OEM seatbelts and the strain of a quick stop let me say the fold in the belt does come out. The upper mount was ripped out of the B pillar but the belt had to be cut to be removed. The SUV was about 11years old and the belt certainly was strong enough the only thing that happen to me has because of the extra length in the belt I hit the dash with my knee and just touched the wheel with my chest, no air bag, (messed up my knee, bruised my chest). The UV rays is the time limiting factor but in racing applications safety is the overriding consideration look at fuelcells vs fuel tanks after all it's a pay to play activity. IMHO

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