Page 1 of 2 12 LastLast
Results 1 to 10 of 19

Thread: Cross link valve, Air bags

  1. #1
    Join Date
    Dec 2012
    Location
    Perth, WA
    Posts
    2,043
    Total Downloaded
    0

    Cross link valve, Air bags

    I'm just wondering if anyone has tried it and if so how it went.

    I thought it would help a fair bit off road. Normally, if there is 1000kg on the rear axle, on level ground, 500kg is shared on each wheel. When the ground becomes uneven with the front wheels, one wheel will carry more weight than the other. Maybe 300kg on one side and 700kg on the other. The result is traction is reduced on the wheel with the less weight. I'm not getting too scientific about spring rates being linear or progressive and stuff causing the weight difference or whatever, just the fact that one wheel will get less weight and therefor less traction.

    If "T" pieces were installed in the air lines to each bag and a airline to link the bags, the air pressure would flow from the higher wheel to the lower wheel and the weight on the wheels should equalise. The front axle would still stabilse the vehilce, along with the anti sway bars.

    A valve could be installed so you could drive around normally but just when you were in that crossed up position, you could flick a switch and allow the weight to equalize and drive out of a normally hung up position.

    I wouldn't suggest having them always open as I am aware that having more pressure on the outside wheel during a corner goes a long way to keep a vehicle upright.

    Happy Days.

  2. #2
    Join Date
    Aug 2006
    Location
    Melbourn(ish)
    Posts
    26,517
    Total Downloaded
    0
    bad plan, its been done as a thread before.

    Short versions

    on a side slope (or any slope) the low side will pressurize the high side making your situation worse.

    on a corner the loaded up side (outside) will transfer to the unloaded side (inside) lowering the outside, raising the inside and tipping you over...
    Dave

    "In a Landrover the other vehicle is your crumple zone."

    For spelling call Rogets, for mechanicing call me.

    Fozzy, 2.25D SIII Ex DCA Ute
    Tdi autoManual d1 (gave it to the Mupion)
    Archaeoptersix 1990 6x6 dual cab(This things staying)


    If you've benefited from one or more of my posts please remember, your taxes paid for my skill sets, I'm just trying to make sure you get your monies worth.
    If you think you're in front on the deal, pay it forwards.

  3. #3
    Join Date
    Dec 2012
    Location
    Perth, WA
    Posts
    2,043
    Total Downloaded
    0
    Quote Originally Posted by Blknight.aus View Post
    bad plan, its been done as a thread before.

    Short versions

    on a side slope (or any slope) the low side will pressurize the high side making your situation worse.

    on a corner the loaded up side (outside) will transfer to the unloaded side (inside) lowering the outside, raising the inside and tipping you over...
    I got the corner thing. I wasn't thinking of a always open sort of valve. Just a momentary.

    So coming up out of a ditch, I turn left and the front left steps up and comes out fine. Rear left starts to climb as does front right, front left now starts to lift into the air and vehilce is rolling to the right. I hope I'm making senses. So pressure in rear right is high and rear left is low. Push button on the dash to open a valve between the rear left and right will allow pressure to drop in the rear right and rise in the rear left and allow the vehicle to roll left, effectivly levelling the vehicle. The extra pressure on the rear right is enough increase traction to drive out.

    Happy Days

  4. #4
    Join Date
    Dec 2012
    Location
    Perth, WA
    Posts
    2,043
    Total Downloaded
    0
    Further to that. If at the time when you were driving up up of the ditch and the front left wheel couldn't get out because the front right and rear left were lifting too much and loosing traction. That wouldn't be a good time to open the valve as the vehicle would roll to the right and become unstable.

    I can easily see why it's not something that would be factory fitted but could be very usefull and safe if used with a bit of uncommon sense.

    Happy Days.

  5. #5
    Join Date
    Aug 2006
    Location
    Melbourn(ish)
    Posts
    26,517
    Total Downloaded
    0
    I can see where you're going with this...


    and excluding that you have the wheel sequence screwed up (the left front will climb first if you turn left out of a ditch)

    have another think about it....

    lets say you're cross axled like you're explaining stuck with diagonal wheels up high taking all the vehicles weight.

    this means the other wheels are already at full droop as limited by another part of the suspension system. But lets for a moment say that what you are propsing works and you get out of your crossaxle, what happens next.

    the one time cross linking really works for you is in a 6x6+ configuration when you link the intermediate to its next closest axle on the same side for load distribution it can give you some articulation benefits on the intermediate axle-its partner.


    IF I was your driving instuctor and you tried to climb the vehicle out of a ditch and you wound up in the condition you are describing I'd fail you for poor route selection and poor vehicle technique.
    Dave

    "In a Landrover the other vehicle is your crumple zone."

    For spelling call Rogets, for mechanicing call me.

    Fozzy, 2.25D SIII Ex DCA Ute
    Tdi autoManual d1 (gave it to the Mupion)
    Archaeoptersix 1990 6x6 dual cab(This things staying)


    If you've benefited from one or more of my posts please remember, your taxes paid for my skill sets, I'm just trying to make sure you get your monies worth.
    If you think you're in front on the deal, pay it forwards.

  6. #6
    Join Date
    Dec 2012
    Location
    Perth, WA
    Posts
    2,043
    Total Downloaded
    0
    Quote Originally Posted by Blknight.aus View Post
    IF I was your driving instuctor and you tried to climb the vehicle out of a ditch and you wound up in the condition you are describing I'd fail you for poor route selection and poor vehicle technique.
    Sometimes you cant avoid it.

    Last weekend we took a short cut down near Pine Creek. The track obviously hadn't been driven since last dry at least. It took us 4hrs to do 8km.

    We came across a creek crossing that had been badly erroded. On our approach side it was over a meter vertical drop, possibly closer to 1.5m. On the other side there was a steep track cutting.

    We were able to enter the creek on our approach side a bit further along but then we had a sharp left turn out of this errosion gulley we were now in. One section there was only about a foot either side of the mirrors.

    The hard left up the cutting started with about a foot step then when up pretty steep. We did it pretty easy with a decent amount of articulation but there was no other way other way to get more square on as we were limited but the gully.

    Video to come.

    Happy Days

  7. #7
    Join Date
    Dec 2012
    Location
    Perth, WA
    Posts
    2,043
    Total Downloaded
    0
    Quote Originally Posted by Blknight.aus View Post
    lets say you're cross axled like you're explaining stuck with diagonal wheels up high taking all the vehicles weight.

    this means the other wheels are already at full droop as limited by another part of the suspension system. But lets for a moment say that what you are propsing works and you get out of your crossaxle, what happens next..
    I can see your point. So if I was crossing a conture bank diagonally or something, got halfway, got stuck, opened the valve, got going with the vlavle closed again, second wheel goes up on the bank with extra height (becasue it was previously drooped) added to the height of the bank and you'd be over.

    I'm only looking at this as a short get out of a stuck situation kind of thing. When your gets creeping through a ditch diagonally because it's the only way you can get through becasue of trees in the way or whatever. Just that little bit of temporary help. Not having it fully open for some big long hill climb and just relying on the front end and anit-sway bars for stability.

    Happy Days.

  8. #8
    Join Date
    Dec 2012
    Location
    Perth, WA
    Posts
    2,043
    Total Downloaded
    0
    Quote Originally Posted by Blknight.aus View Post
    and excluding that you have the wheel sequence screwed up (the left front will climb first if you turn left out of a ditch)
    Yep, you're right. Fixed.

    Oh and glad you're not my driving instructor otherwise, I'd still be stuck down near Pine Creek digging a new cutting across the errosion because you wouldn't let me turn up out of a ditch. LOL

    Happy Days

  9. #9
    Join Date
    Aug 2006
    Location
    Melbourn(ish)
    Posts
    26,517
    Total Downloaded
    0
    Quote Originally Posted by joel0407 View Post
    Yep, you're right. Fixed.

    Oh and glad you're not my driving instructor otherwise, I'd still be stuck down near Pine Creek digging a new cutting across the errosion because you wouldn't let me turn up out of a ditch. LOL

    Happy Days
    no you wouldnt be

    If you'd gotten that far with me as your instructor the moment you cross axled it and bitched about needing more articualtion you would have noticed 2 things.

    Firstly my rapid relocation from the passengers seat to somewhere shady with a quick detour via the settling dust you'd find yourself standing in the middle of.

    the second thing you would notice as the dust finished settling would be 2 pairs of parallel, perpendicular lines on the ground surrounding you revealed themselves to the dying sound of my taunt "when you can think outside of it, you can step outside of it"

    Ignoring the 3 golden rules for a minute since you already got into the situation in the first place

    what else could you have done....
    Dave

    "In a Landrover the other vehicle is your crumple zone."

    For spelling call Rogets, for mechanicing call me.

    Fozzy, 2.25D SIII Ex DCA Ute
    Tdi autoManual d1 (gave it to the Mupion)
    Archaeoptersix 1990 6x6 dual cab(This things staying)


    If you've benefited from one or more of my posts please remember, your taxes paid for my skill sets, I'm just trying to make sure you get your monies worth.
    If you think you're in front on the deal, pay it forwards.

  10. #10
    Join Date
    Sep 2010
    Location
    Branxton NSW
    Posts
    581
    Total Downloaded
    0
    Quote Originally Posted by Blknight.aus View Post
    no you wouldnt be

    If you'd gotten that far with me as your instructor the moment you cross axled it and bitched about needing more articualtion you would have noticed 2 things.

    Firstly my rapid relocation from the passengers seat to somewhere shady with a quick detour via the settling dust you'd find yourself standing in the middle of.

    the second thing you would notice as the dust finished settling would be 2 pairs of parallel, perpendicular lines on the ground surrounding you revealed themselves to the dying sound of my taunt "when you can think outside of it, you can step outside of it"

    Ignoring the 3 golden rules for a minute since you already got into the situation in the first place

    what else could you have done....


Page 1 of 2 12 LastLast

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Search AULRO.com ONLY!
Search All the Web!