dave morris

Understand that a recent SCCA Participant Bulletin states that "the use of full-face or closed-face helmets while driving vehicles with active airbag restraint systems may result in injuries in the event of a crash that deploys the airbag." The bulletin explains that in a crash with airbag deployment, contact with the chin area of a full-face helmet can be so powerful that the risk of fractures to the jaw cannot be ruled out. SCCA "highly recommended that full-face helmets not be used in vehicles with functional airbag systems". I'm unclear just why the full-faced helmet is singled out ... presumably the same problem doesn't exist with an open-faced helmet? Anybody know?

Bill Gregory

Dave,

You might want to do a search on this, believe there was a discussion on this recently.

dave morris

Bill,

Thanks. Yes, I did a search before posting and again after your note. Lots of general stuff about what helmet to buy ... Snell ratings ... etc ... etc... but I didn't see anything addressing the recent SCCA Bulletin. Appreciate your help directing me to the relevant posting you refer to.

Dave
'97 993 coupe
'84 911 coupe

dave morris

Bill,

Sorry. You are right. I kept searching/changing subject words ... and found the postings dated 11/18/04. No one there seemed to understand the SCCA's reasoning either.

Dave

SundayDriver

This is my guess, and it is only a guess...

An aribag is deformable, so when it hits you in the chin, you are cuishoined. Add the chin bar of a full face helmet and you are being hit with somethinb solid. This is not really an issue in SCCA racing because airbags must be de-activated. But that is not the case in Solo, so that is what that advisory is directed towards.

For DE, most people are making a number of safety compromises - Generally no roll cage/bar, do you run harnesses? How effective are the mounting points for your harnesses? If you do have a rollbar or cage, are you risking serious head injury because it is where you might hit it in a street accident? Etc, etc.

In this case, you have to decide if the benefits of a full face helmet outweight the risks - there is no one who can really give you that answer as racing safety equipment is just not tested in semi street car configurations.

JBH

Sorry - could someone please post the thread referenced above?

Until then, let me ask a silly question: wouldn't the harness keep the head & helmet from ever colliding with the airbag.

Brian P

Belt's stretch, and unless you have a HANS device (or equivalent), your neck stretches too. I wouldn't be surprised to see your head still hitting the airbag. I also wondered if it would be better to disable it.

And... a bit OT, but I think it may be better to disable it for street driving provided you always use your seat belts.

JBH

I guess I didn't think the bag would reach that far.

This is a question of particular interest to me - I still have the OEM wheel with harnesses, etc. It's a pain, but it seems to me if I am going to drive on the street, I want maximum protection so the regular belts are gone and I only use the harnesses pulled tight. I would really like to get rid of the OEM wheel and move to something smaller and removeable. If I am better to have it gone on both track and street, then the decision is easy.

macfly

JBH, have a look at the videos on this site, it is really illuminating.
http://www.hansdevice.com/
I ordered one, and a new custom rear cage that will be HANS compatible but also road safe, after spending some time on thier site. Even though I'm only a trackday & DE junkie I never want to get caught without one in a track accident now. With the HANS I'll also be leaving my airbag connected, as I drive to and from the track. It could save my life on the road, a place I always feel in more danger than on the track.

HarryD

This was discussed to some depth on the Rennlist E-mail list for 911/993/996's. The subject was "Full Face Helmets In Cars With Airbags".

You can find the information here: http://www.rennlist.org/lists.htm

Z-man

Actually, most 5/6 point racing harnesses are not DOT approved, therefore they are illegal to use on the street.

First off, most harnesses do not have any UV protection in them, like the stock seatbelts do. (IIRC, that's the main reason they only have a 10 year life expectancy)

Secondly, racing harnesses are designed to stretch, while modern seatbelts are designed NOT to stretch. I think the difference between the two is because most race cars offer very little impact absorbtion, and the belts need to stretch in order to absorb some of the impact to the body. In a street car, there is a lot of impact absorbtion built into the car and thus, it is safer to keep the occupant firmly planted in his seat while all this transference of energy takes place. Also: air bags work better on a person that hasn't moved from the air-bag's 'target zone.'

Some people use both the stock seat belts with the racing harnesses on the track - I question the usefullness of that setup - seems the two systems work differently - one keeps you snug in your seat (seat belts), while the other one stretches more (harnesses).

[Side bar: some car companies have 'pre-tensioners' in the seat belts that actually tighten the seat belt via a small charge that pushes & tightens the seat belt. - similar charge to what's used in airbags, only less force. This pushes the occupant back into the seat (further from the airbag) and after the initial impact, the belts get a little slack and allow some movement of the occupant. ]

About airbags: IMHO, they are the best safety device invented for modern cars. On the street, they have saved lives. I am sure that in DE's they have done the same. I don't club race, but I do autocrosses and DE's, where there can be a real potential for an off-track and a collision. I have not deactivated my airbags in my 944S2, and do not plan on deactivating them at all. Sure, the airbag may hit my head, and given that I use racing harnesses while on the track, my noggin' may be closer to the airbag than what is ideal, but I'd still rather have an airbag (soft, filled with air) make contact with my helmet & face than the steering wheel or windshield!

Now I have heard that there are conditions where an airbag may deploy on the track without a collision - under certain 'massive' braking conditions, the airbag computer may be fooled into thinking the car has hit something. I have heard of this, but have NEVER seen anything like that actually happen! I simply don't believe that even a 911 cup car has THAT much braking force that would cause the airbags to go off. (Maybe if the sensors aren't checked and they are old, it could be caused by a mis-fire, but I don't know).

So (to sum up my disortation above), this is what I do on my tri-purpose 944 (street/autox/DE-track):
1. Airbag not deactivated.
2. Stock seatbelts used for street.
3. 6 point harnesses for autox and DE-track use.

I haven't read the SCCA reasoning for the airbag disconnect rule - I will read up on that before commenting anything more than I really don't understand their reasoning - I'd rather hit something soft than hard with my head, even if that something soft is coming towards me faster than my head is moving towards it!

Sorry for my rather long post here.
-Z-man.

Geo

Unless you have some proof of the above, I'm going to dispute this. AFAIK neither have anything done to them to protect them from UV. Without going into a very long post, the SFI ruling on two year belt replacement is IMHO nothing more than a ploy for their members to sell more belts. I did a lot of research on this. Even the military replaces belts as necessisary. There is no mandatory replacement cycle and helecopters live in a much harsher environment. I've come across nothing about safety belt fibers given any sort of treatment to protect them from UV. And I'm not so sure about that life expectancy of stock belts.

They all stretch. How much depends upon the material used (polyester vs. nylon). Both materials are used in racing belts, including FIA homologated belts.

They have also taken lives.....

Good luck on finding some reasoning spelled out. I think most important is to not have an explosive device inside a race car.

Z-man

I'll need to do some research on that - hopefully I can get back to you.
True - I should have said that stock seat belts stretch LESS than racing harnesses.
I guess they'll soon be requesting that the internal combustion motor be removed prior to going out on the track!

-Z.

Geo

You sure about that? Again, I would think that would depend more on material.

Brian P

I would think long and hard about that if I were you. The airbag is only soft AFTER it has already expanded. If you are sitting too close, you are hitting a still expanding airbag which is most definitely not soft. In fact, it has proven to be lethal many, many times in the past, and it's the reason that manufacturers are now putting in smart airbags for lighter (and hence, likely shorter) people.