Thread: L322 ARB bullbar (and snorkel....:)

Hi Laurie,

I'm a little confused now about the comment regarding interference with the curtain airbags from side rails.

I can see issues with airbags from "tree rails" that traditionally attach at the bullbar and then run down to become sliders under the sill, protecting the fenders. That sort of continuous run is going to mess with the inertia sensors big time as they would disperse the shock loads in all sorts of ways the vehicle designers never intended. I don't see the same issue with separate "sliders" along just the sill though. Any side impact large enough to trip the side sensors is still going to be effective with some sort of slider as it is attached to the sill (or chassis rail under the sill). Crush rates and crumple could be affected sure but the airbags would still fire as expected. Maybe I'm missing something.

Land Rover make a set of fairly substantial side rails for the L322. They call these "Side Protection Tubes", Part# VUB001230. These are significantly more robust than the aluminium side steps for the vehicle, although they aren't "steps". I have seen them close up fitted to a vehicle and they looked at least as beefy as a set of sliders I had on my D2 a while back.

If LR can market these for fitment to the vehicle how do they get around the airbag issue? Just wondering.

Cheers,
Iain

Hi Iain
I approached the local ARB agent early last year about a set of steel side steps similar to the ARB set on my D2 for a L322. This is where I was told about the side curtin air-bag problem. I believe that ARB still don't make the steel side steps for the Landcruiser/Prado models with side air bags.
Are these the tubes you are talking about below ?


Just a thought, it may be the side crush-cans for the air bag activation are overly protected and may be late/no activation as the force would be spread along the steps the most pressure being on the mounting points ? The tubes look almost level with the side of the vehicle, so any reasonable force would trigger the airbags. Check the height of the side sensor below.


I agree for underneath protection, they would be good, if you could put the light weight steps over them you would have the best of both worlds !

Laurie

Missing Image !

Hi Laurie,

Thanks for the feedback, and the pictures!

Seems to me that since all the airbags rely on inertial sensors to trigger deployment, that it shouldn't make much, if any, difference if there is a side rail or not. In terms of actual body deformation rate (or crumple) it would certainly make a difference. This is ultimately going to have some influence on the effectiveness of the airbags.

A case in point for this is the extensive testing that has to be performed with any sort of frontal impact protection. New crush cans have to be created so that the vehicle decelerates (or crumples) at a similar rate as without the frontal protection. This is so that the airbags are not the only things decelerating the occupants, while the occupants are having the full force of the impact transferred to them as they hit the airbags. This would result in significantly greater injury.

In a similar fashion the side airbags have their own limits in terms of what would most likely be "survivable" side impact forces. Anything too robust along the side of the vehicle is going to impart significantly greater force on the occupants than if the bodywork absorbed some of the impact energy during airbag deployment.

I'm guessing here but I suspect that the design of the bars, and the mounts, mean that the bulk of the bodywork still comes into play as part of the energy dissipation process. Though not as much as without the bar present. This is possibly considered to be an "acceptable" margin increase.

The LR bars sit about level with the sills so would do the job of a traditional "slider" sill protection bar.

From the RAVE excerpt it appears that the sensor is at about sill height so I'm guessing it would trigger at pretty much the same velocity with or without the bar in place.

I'm sure there are engineers out there doing all sorts of fancy math to determine what will, or will not, work effectively to protect the occupants for many different energy transfer and dissipation scenarios. That's possibly why they are paid the big bucks.

Them's my thoughts anyway. I have some others about the ARB agent but I'll keep those to myself for now.

Cheers,
Iain

Originally Posted by Tunny

Hi Waverley,

Do you have any pics? Also what was the cost for the rails and under body protection as I have been trying to source for some time.

Regards

Tunn

Tunn,

Sorry, just saw your post. I will get some pics and put them up and dig out the costs. Cheers. Rob

Saw an L322 Range Rover yesterday travelling south down Sydney Rd near Fawkner - it had a safari snorkel and was towing a bigish off road van.

I did not think you could get a Safari snorkel for the RR.

Cheers

Originally Posted by chuck

I did not think you could get a Safari snorkel for the RR.
Cheers

They don't... Wonder if they have modified something else they have like a D3/D4 unit?

Next time you see it, chase them down and ask them how they did it.

Iain I agree completely with what your saying ! have a look at these sliders

Mk III Range Rover sill protectors and side steps

They look the goods !

Laurie