urBan_dK

I don't understand why people always recommend turning off the airbags once a racing harness has been installed.

I have just purchased Scroth Profi II ASM with an additional 2-pt sub-belt. My car already has fixed back racing bucket seats and roll bar w/harness bar.

My car sees dual duty for street and track, and please don't lecture me about the compromises involved, I know them all and have assessed all my options. I just want to know what the harm is in leaving the airbags on.

krnmike

u actually don't need airbags..

racing harness are woven so that the fabric stretches under load. (if it didn't, during those 100+mph crashes, necks would rip off from the force. The harness will elongate the force time).

that's why it's also recommended that they are replaced after couple years or an accident.

i'm not sure why they say to turn off airbags,
but as far as the human reflexes work, i think people tend to crouch and shrug their heads inbetween their 2 arms that are still on the steering wheel (basically they look down and close their eyes until the crash it over). this way your head is pointing right at the airbag combustion which is dangerous.

mikegarrison

Not quite. It is recommended (usually required) that they be changed every five years due to the observed fact that nylon does age. (This is often attributed to UV exposure, but there is more to it than that.)

Replacement after a hard crash is for a different reason. They will be both less strong and less stretchy due to microtears and melting/fusing of the fibers in the weave.

Burgman

I think the rule is no racing harness without a roll bar. The racing harness will not let you duck if the car starts to roll over so you also want a roll bar with the harness.

mikegarrison

Removing the air bags is common, but mainly just because they are not needed with the harness and can often be sold for cash money.

urBan_dK

Okay. Thanks for the quick responses.

So, from my understanding, removing the airbags is more an issue of weight savings than a safety issue. Or, put another way, leaving airbags in a car with a full 6-pt harness is not going to cause any additional safety concerns.

And thanks for not jumping down my throat. I heard that posting in the RaC forum can be a bit rough.

krazik

not exactly a harness problem. The issue is with helmets and air bags.

In some cases an airbag can break your neck when deployed in to a helmet.

Googling, this was at the top:
http://www.bimmerfest.com/forums/showthread.php?t=78914

mikegarrison

That's been pretty much discredited.

krazik

interesting, good to know. any links on that?

mikegarrison

The issue was that somebody thought there was a chance that airbags would cause jaw fractures (not neck fractures) when used with full-face helmets. SCCA investigated a bit and decided there was no real evidence this was a likely problem. But it lives on in memory.

There was an SCCA advisory in 2004 warning about possible rulemaking in 2005, but I don't have any links.