Outer Limits 4x4 Board

mate asked me to see what ppl do with airbags (the safety ones)... do most ppl disable them (pull a fuse or something) when going offroad, or just leave it? he's worried 'bout setting them off by diffing out or coming down hard on a rock etc.....

he drives a jabber, mid 90's V6 i think....

Has anybody had first-hand experience of this happening in the real world? (Don't tell me about incidents from the US of A - they have real large super-sensitive airbags because they're too f*****g dopey to wear seat belts!)

Airbag sensors are typically chassis mounted, and require HUGE G-Forces to trigger them - typically lateral deceleration in the order of 3+ Gs. If he biffs his Jabber that hard off-road then replacing airbags is the least of his worries.

As an aside: Mercedes Benz had to modify their systems a few years back, to trigger airbags at lower G-Forces, below the level where the airbags are actually required. This was because too many customers had minor fender-benders and complained that the airbags didn't work. They weren't injured, they didn't need the protection offered by airbags, they just expected them to fire.

Cheers,

Scott

We havn't had it happen yet but I have a feeling we were close. After motoring up a big sand hill there was a large pot hole and disco got thumped pretty bad, enough to set off the hazards (some safety thing where if you have an incident the hazards are set off to warn otheres in bad lighting?). It was a pretty hard knock so unless you doing dirt jumping or something you should be right

To actually answer your question we don't actually do anything to disable the airbag. Also come its due replacement date (2007, 10 years service life) I doubt we will rellace the airbag unless its quite cheap to do so.

Stuart

I know that on a mates GU, Nissan pulled the fuse out to straighten his steering wheel after I lifted it 6 inches. Dont know about Pajeros but.

LudaCris

Blown one up at TAFE using a 12v battery and some wire!

Think a 12guage is loud? Once you have seen one of those f*ckers (air bags) go off you dont want to be in any accident. Trust me.

I always figured they'd disengage when you put them in 4L, maybe even 4H, but I base this upon nothing other than a random guess

I leave it all active. When I go out of control down a hill and whack a tree I want the airbag to go off. If you hit something that hard to trigger it, you'll probably need it.

I personally know 3 trucks that compete in most of the biggest comps in Aus and Kiwi land and all 3 have never experienced the airbag going off during competition...and yes they have thumped their trucks pretty god damn hard.

Like it was said above...If you whack ya truck hard enough to set them off...I think I would want them to go off!

But on the other side of the coin, I own hj60 and my airbag goes off all the time...But then she gets out and all is good once again

Gribble wrote:Blown one up at TAFE using a 12v battery and some wire!

Think a 12guage is loud? Once you have seen one of those f*ckers (air bags) go off you dont want to be in any accident. Trust me.

Yeah done that found one in a dumped/ trashed VT out in the sticks one day. Belted the steering wheel off with my axe. set the airbag off in my garage. Gribbles is right they are loud! all I could think about when going for a ride in my mates VY SS ute while he was fanging it was BANG as I was looking at the "air bag" logo on the dash right in front of my face. They let out some toxic shit too. Had to air out the shed, you couldn't breath in there.

Might be a Nissan thing but i dont like there airbags for 2 storeys

A few years ago i went 4x4ing with the people from opposite lock in Newcastle ,when the owner towing a camper trailer on wet road tried to turn into the camping ground at mungo and failed to make the entry but managed to hit a big a$$ concrete pole ,managed to buckle there new bullbar on the nissan .
They where travelling at about 40kph when impacting and they themseleves where suprised the airbags didnt go off.

About 1 year ago i T boned a Holden Appolo at 60Kph managed to right of the Holden and put both chassis rail of the nissan thru bumper bar,broke both headlights,bent steering,bent bonnet,broke windscreen and still dint have the air bag go off Silly lady drove straight thru a give way sign

revin wrote:Might be a Nissan thing but i dont like there airbags for 2 storeys

A few years ago i went 4x4ing with the people from opposite lock in Newcastle ,when the owner towing a camper trailer on wet road tried to turn into the camping ground at mungo and failed to make the entry but managed to hit a big a$$ concrete pole ,managed to buckle there new bullbar on the nissan .
They where travelling at about 40kph when impacting and they themseleves where suprised the airbags didnt go off.

About 1 year ago i T boned a Holden Appolo at 60Kph managed to right of the Holden and put both chassis rail of the nissan thru bumper bar,broke both headlights,bent steering,bent bonnet,broke windscreen and still dint have the air bag go off Silly lady drove straight thru a give way sign

What were your injuries? The sensors are clever little buggers, they know what sort of deceleration is required to seriously hurt the occupants. If you walked away the airbags weren't required.

If you're still not convinced, consider the findings of an article from (Wheels or Motor - don't remember which) magazine comparing repair costs for some "typical" Australian family cars involved in an accident just significant enough to set off the airbags. This was not long after Commodore and Falcon introduced them, and for some vehicles the greatest part of repair costs was replacing airbags and the bits they broke. A Subaru was the worst performer - over $6k for airbag related stuff, including new windscreen and complete new dash. Repair cost for Falcon and Commodore were around $6k - total!

Cheers,

Scott

I recieved a dirty big bruise across my shoulder from the seat belt,the other guy in the car same plus hit his knee on the dash board .Lady in other car 2 days in hospital neck injury and cuts from her head going thru the side window on impact .

I just thought with pushing chassis rails thru the bumper would of been enough impact to activate the air bag. I know from this crash that you must have to have a big impact to active them .

At the end of the day everyone was OK so thats all that really matters

Then what's your opinon of a bullbar on a airbag equiped car?
Do u think it's lethal?
To my understanding there are such thing as airbag complaiant bars but i dont get it how would it trigger when needed?

Air bags are designed to activate in a direct fore and aft collision mode. Side airbags use a second set of sensors to equate side impact protection.

One of our clubies doing the sand at Portland hit the base of a dune with a bit on momentum and "Hmm" went the airbag.

Early model USA built cars had their sensors set to trigger at the 50 kmph mark and it was way to sensitive. Most are now set to trigger at the 60 kmph mark and I'm surprised at some of the stories here and out the bags not doing their job at that speed. They should have deployed in a 60 kmph bingle.
Front protection bars are another story with air bags. They can interfer with the crumple zones in the front of the vehicle and transmit false sensor readings which will deploy the air bags when not needed. In reality, a bingle at about 60 kmph will trigger the suckers needed or not! Problem is if you have a non-compliant FPB you may end up paying for air bag replacment as insurance may not. Your call here.

Can you disable them? Most vehicles are now fuse equiped for the air bags and you can pull same out. My suggestion is to disable them when sand driving but not elsewhere. Most 4X4 work is under the deployment speed anyhow so it's probably not an issue.

Lastly - if you do happen to come across a bingle that looks medium to high speed impact and go to help - be very cautious of non-deployed air bags. Don't lean into the car or place yourself between the occupants and the air bag. You may get a nasty surprise! Some systems take up to 15 minutes to disarm the airbags.

one of the blokes at dad's work was sand driving in a rav 4, hit the bottom of a dune with some momentum (under 40 k's an hour easy though) and set them off.. older model, apparently they don't use impact sensors, but momentum sensors or something, if that makes any sense, and the change in momentum from forward at 35, to upwards at 35 triggered them (3rd hand from the toyota guy who restuffed them)

Also for info, the sensors for the airbag are all under the dash of 95%of cars. They are no where near chassi's are bullbars. Those crush tubes are just designed to take some of the impact in a decent bingle.
And yep they do take 15mins plus to deactivate. Some of the newer stuff with 10plus airbags/curtains, take longer.

thanks for that guys, kinda what i expected.... i'm sure my mate will appreciate the info

turps wrote:Also for info, the sensors for the airbag are all under the dash of 95%of cars. They are no where near chassi's are bullbars. Those crush tubes are just designed to take some of the impact in a decent bingle.
And yep they do take 15mins plus to deactivate. Some of the newer stuff with 10plus airbags/curtains, take longer.

Most of the vehicle I look at have the airbag DERM in the dash/console area but the actual impact sensors are on the front sheet metal or front chassis rails. Maybe I look at different cars to you but that is just my experience. Most air bags will not deploy unless the imact is within 30 degrees of centre of the vehicle so the bags will not deploy unless the accident is a frontal type.

If you get bored look up the statics of how many children are killed each year in the US from passengers airbag flaps. Children are better off without the airbag if they do not have enough weight.

I would leave the bags enabled as the vehicle computer should be able to work out when they should be deployed.

auto_eng wrote:
If you get bored look up the statics of how many children are killed each year in the US from passengers airbag flaps. Children are better off without the airbag if they do not have enough weight.

I would leave the bags enabled as the vehicle computer should be able to work out when they should be deployed.

Had a look at a H2 Hummer about 3mths back and it was possible to change the mods of the atleast the passenger airbag. Think it had 3 settings, so at a guess they would be. No seat belt, wearing seatbelt and off.

Those airbags have a few setting that depend on a fair few inputs to determing the strenght of the deployment. Weight of occupant, proximity to air bag, presence of Child Seat and some others. They can get a bit tricky.

I deal with air bags in a emergency capacity..
They r tricky and unpredictable things so be real careful playing around with them...
On many vehicles even if u pull the fuse the SRS system can be still active for as long as 30 mins (some even longer)..
They operate in the area of 100th's of a second.. The US ones r considered even faster..

I have personally tested and seen tested numerous types from different vehicles..U dont get a chance to blink before they activate...
I have also been to numerous accidents, some big some small, and the airbags don't always activate...

While we are on the SRS thing (Supplementry Restraint System) don't forget about seatbelt pre-tensioners....

O, and the powder they expel usually contains corn flour, still not good for u anyway..

Just some practical info for u

Rob

Because the americans refuse to be told to wear seatbelts airbags for the US market are larger and inflate faster.

When Oz manufacturers started introducing airbags they developed their own, and for a while they were the best in the world. Because we wear seat belts they can be smaller (approx 35 litres, vs 65 litres for US bags.) They were even folded differently to minimise injuries on deployment - US and European bags were folded with outer edges over the top of the middle of the bag - these would "swing" out on deployment and often create significant grazes to occupants. I also read that the top edge swinging up was considered responsible for killing people - catch them under the chin and snap the head back, breaking the neck. Australian bags are folded with the edges under/behind the front of the bag, so the centre of the bag comes straight out on deployment, and everything else comes out from behind it. Because they are smaller they can inflate at a slower rate, which also helps reduce some of the forces involved in deployment.

And speed has nothing to do with it - it's change of momentum over time. Your car can be stationary and hit by an oncoming vehicle - if the impact forces are sufficient, your airbags will deploy even though your vehicle was travelling at the dizzying speed of zero kilometres per hour.

Cheers,

Scott

when they first implemented air bags in the USA.... they had a few incidents of people being decapitated by them because they had far too much power in them others were being far more seriously hurt than they should have been for the speed of the accident. I have been to an accident (with the RFS) with the car nearly folded in half with airbags that haven't deployed (obviously because it was a side impact) regardless, a tow truck driver stuck his head in the vehicle right in front of the steering wheel to take a look he's lucky he didn't lose his head....

I think from 95 on all US cars have to be fitted with a drivers airbag.
On the US Trail Talk Jabber forum there are lots of 95+ models with drivers airbags and none have been triggered. It certainly has been discussed and apparently there is a fuse you can pull to de-activate it but the consensus was it just wasn't necesary.

tritonasaurus, you dont work at the rta crashlab do you mate????