Another good reason to run Airbags
- Thread starter Beowulf
- Start date
adrenaline503
Explorer
That is one reason I am going to the on my Frontier. My wheelbas is SO long that even a few inches at the rear axle make a huge differcence. They can also create some negative travel if you need more traction in a high center or off camber situation, assuming youre loaded down, which I am sure I will be.
adrenaline503
Explorer
Lynn said:
I do get some roll in my wildernest when the rear suspension compress, even climbing up to the bed areas induces quite a bit of movement. I do think the airbags will help with this. I hadnt thought of the leveling aspect, good point.
kcowyo
ExPo Original
Lynn said:
Marketing hype. I've tried it. It doesn't really work.
Airbags are great, the leveling on an unlevel campsite is the only claim I call BS on. They are excellent in all other aspects.
I'm surprised the quoted user on ROF ran the Rubicon with only 5psi in his bags. Why start out with minimal psi? If he'd had 20 or 30 psi when he started, he probably wouldn't have gotten hung up at all...? It's a good endorsement though for the product, it's just curious why he didn't have them aired up the whole time.
kcowyo said:
Why is that? I actually hadn't heard any hype, just made an assumption (and you know how those are). Seems to me if buses and special-needs taxis can use 'em to 'squat', an expo rig could use 'em to level. Matter of fact, don't some of the high-end RVs use 'em that way?
kcowyo
ExPo Original
Lynn said:
Well the difference between the bag size on say a Toyota or Jeep vs. a large RV or bus is the first thing. For a standard sized vehicle, the airbags are about the size of a pop can. On a bus or RV, the bags are the size of a keg. I would assume (there's that word again...) that airbag systems on high end RV's and busses that are designed to carry 10x the weight of my Toyota or a Jeep, are more a little more sophisticated.
Brian/goodtimes, once explained to me in very mechanical terms why lowering pressure on one side will not make a truck or jeep level. It made sense when he explained it to me and we were standing beside my truck in a campsite.
The best I can offer (and I'll pm goodtimes to chime in here) is to visualize a 4 legged table set up on a sloped hill. When you set a glass in the middle, it will slide off due to gravity right? Now cut one of the legs on the high side short and set the glass on top in that corner. The other end or opposing corner will pop up. It's creates a see-saw, teeter-totter effect. But if you cut the two legs on the high side short, then you should have a level table. So perhaps airing down the front tire on the same side would help a vehicle level out. I'm assuming....
I said marketing hype because it is a benefit the manufacturers use to sell their bags. But I've never been able to make it work, nor have any other owners I've spoken with really been able make a noticeable leveling difference by airing down one bag.
articulate
Expedition Leader
Right. I believe that full suspension air bags will provide far more range in height. Bags designed for just improving your load management and road manners with added weight are just not large enough to make more than a couple of inches worth of difference.kcowyo said:
Park on a rock. Call it done.
Ron B
Explorer
I have posted about my airbags a few times here, but not in depth. So I'll thow in my 2 cents:
I have zero experience with solid axle trucks, but I know of the Air-rock system and a few who have it and love it. It can be done and can be a relatively dependable solution. I'm using "relatively" because 1) all air systems leak and require a bit more routine maintenance, and 2) what can be more dependable than a purely mechanical system/shock/spring?
I have a hummer h1 (4 wheel ind susp) and replaced the springs with bags last May. I guess just saying "replacing the springs with bags" is an over-simplification as I also had to re-locate the shocks and add limit straps (still working on bumpstops). The trick was finding the right bag, and there are hundreds to choose from. My truck is pretty heavy (8000 lbs on the trail -- 10,300 gvw) so I had to choose accordingly. I have each bag plumbed independently (safer on the road) to manual pneumatic switches on the dash so yes, fine tune adjustments are easy. I do not have a leveling/computer controlled system on board -- I use a bubble to level it out while driving (an inclinometer like many of you have for wheeling). I wanted to keep the system as simple as possible and wanted to stay away from electronics (though I am making a change to digi guage soon - the analogues are just not accurate/dependable in my application).
Variable height and a smoother ride was attractive to me -- I needed a lift, but still needed to fit into my garage as well as local parking garage. We've all chipped teeth on washboard sections of trails, so the smoother ride was also a plus. I wheel the truck hard and so far it has worked out very well. My stock clearance with my 37" tires was about 15.5" to my undercarriage protection, now I can get to about 19", maybe 20" (but then I'm getting close to maxing out the cv/balljoint angles).
I'll attatch some pictures if you guys want, but for now I'll leave it at my 2 cents (maybe less?).
Ron B
I have zero experience with solid axle trucks, but I know of the Air-rock system and a few who have it and love it. It can be done and can be a relatively dependable solution. I'm using "relatively" because 1) all air systems leak and require a bit more routine maintenance, and 2) what can be more dependable than a purely mechanical system/shock/spring?
I have a hummer h1 (4 wheel ind susp) and replaced the springs with bags last May. I guess just saying "replacing the springs with bags" is an over-simplification as I also had to re-locate the shocks and add limit straps (still working on bumpstops). The trick was finding the right bag, and there are hundreds to choose from. My truck is pretty heavy (8000 lbs on the trail -- 10,300 gvw) so I had to choose accordingly. I have each bag plumbed independently (safer on the road) to manual pneumatic switches on the dash so yes, fine tune adjustments are easy. I do not have a leveling/computer controlled system on board -- I use a bubble to level it out while driving (an inclinometer like many of you have for wheeling). I wanted to keep the system as simple as possible and wanted to stay away from electronics (though I am making a change to digi guage soon - the analogues are just not accurate/dependable in my application).
Variable height and a smoother ride was attractive to me -- I needed a lift, but still needed to fit into my garage as well as local parking garage. We've all chipped teeth on washboard sections of trails, so the smoother ride was also a plus. I wheel the truck hard and so far it has worked out very well. My stock clearance with my 37" tires was about 15.5" to my undercarriage protection, now I can get to about 19", maybe 20" (but then I'm getting close to maxing out the cv/balljoint angles).
I'll attatch some pictures if you guys want, but for now I'll leave it at my 2 cents (maybe less?).
Ron B
goodtimes
Expedition Poseur
It looks like 2 different things are being discussed. Air bags can be used to either augment the spring rate (act like a helper spring), or they can be used to support the vehicle (instead of a spring).
Most aftermarket air bags are of the helper-spring type. These can only lift a vehicle (increase the pressure in the bag, and you effectively increase the spring rate of that corner of the suspension). The only way these can lower a vehicle, assuming a typical installation, is if the air bags were already filled to a point where they were lifting the vehicle. If that is the case, you can lower the vehicle to the point where all the weight is on the OEM spring (or the spring in the OEM location).
Can you level out a camping spot? Yea, sure. If you need to raise one end (both corners, front or back), you can increase the pressure on that end....but you are limited by the amount of suspension travel you have. If you have 3" of down travel on the front of your IFS truck...you are only going to be able to lift the front end of the truck by that 3".
Trying to level one front corner of an IFS rig is much more difficult, because of the way the weight transfers (remember the weight bearing spot (sprung weight) is where the arms attach to the frame--close to the centerline of the vehicle). So when you increase pressure, you are lifting the vehicle from that load bearing point...since it is close to the centerline of the vehicle, it picks up some of the weight from the opposite side.
With strait axles, you have more control because the load bearing point is farther away from the centerline of the vehicle. It is still only minimally effective though, because you can still only lift with this air bag type, and you are still restricted by suspension travel.
Now, if you are using a air suspension in the truest sense of the term, then you no longer have springs...just the air bags. In this case, you are sitting on your bump stops until you add air to the bags. You increase pressure to acheive ride height. Once at that height, you can use pressure to raise (within the limits of the suspension), or lower (down as far as the bumpstops allow) a vehicle. Since you control both up and down, you have more room to adjust for uneven terrain. You are still limited by the mechanical components of the suspension (link length, bump stops, geometry, mechanical intereference, etc).
In typical applications (ignoring rock buggies, custom suspensions, etc), your ability to level off a parking spot with the use of air bags are pretty limited. You can get a couple inches, but that is about it.
The see-saw deal really isn't applicable to a truck, like it is a table or chair. With a chair or table, you would need to shorten a minimum of 2 legs to level it off (depending on orientation....you might need to shorten 3). But with a vehicle, as you shorten one corner, the weight removed from that corner is transferred to the others, which further compresses those springs, which results in those corners being lowered as well...which increases the pressure on the corner you shortened. If you shorten one corner so far that the other corners cannot compress any further, then yes, you have the see-saw effect....but that is quite a ways, and remember, with the helper type air bags, you can't shorten....only lift. So it is a moot point anyway.
Did that clear things up KC? Or did I make it worse.eepwall:
Most aftermarket air bags are of the helper-spring type. These can only lift a vehicle (increase the pressure in the bag, and you effectively increase the spring rate of that corner of the suspension). The only way these can lower a vehicle, assuming a typical installation, is if the air bags were already filled to a point where they were lifting the vehicle. If that is the case, you can lower the vehicle to the point where all the weight is on the OEM spring (or the spring in the OEM location).
Can you level out a camping spot? Yea, sure. If you need to raise one end (both corners, front or back), you can increase the pressure on that end....but you are limited by the amount of suspension travel you have. If you have 3" of down travel on the front of your IFS truck...you are only going to be able to lift the front end of the truck by that 3".
Trying to level one front corner of an IFS rig is much more difficult, because of the way the weight transfers (remember the weight bearing spot (sprung weight) is where the arms attach to the frame--close to the centerline of the vehicle). So when you increase pressure, you are lifting the vehicle from that load bearing point...since it is close to the centerline of the vehicle, it picks up some of the weight from the opposite side.
With strait axles, you have more control because the load bearing point is farther away from the centerline of the vehicle. It is still only minimally effective though, because you can still only lift with this air bag type, and you are still restricted by suspension travel.
Now, if you are using a air suspension in the truest sense of the term, then you no longer have springs...just the air bags. In this case, you are sitting on your bump stops until you add air to the bags. You increase pressure to acheive ride height. Once at that height, you can use pressure to raise (within the limits of the suspension), or lower (down as far as the bumpstops allow) a vehicle. Since you control both up and down, you have more room to adjust for uneven terrain. You are still limited by the mechanical components of the suspension (link length, bump stops, geometry, mechanical intereference, etc).
In typical applications (ignoring rock buggies, custom suspensions, etc), your ability to level off a parking spot with the use of air bags are pretty limited. You can get a couple inches, but that is about it.
The see-saw deal really isn't applicable to a truck, like it is a table or chair. With a chair or table, you would need to shorten a minimum of 2 legs to level it off (depending on orientation....you might need to shorten 3). But with a vehicle, as you shorten one corner, the weight removed from that corner is transferred to the others, which further compresses those springs, which results in those corners being lowered as well...which increases the pressure on the corner you shortened. If you shorten one corner so far that the other corners cannot compress any further, then yes, you have the see-saw effect....but that is quite a ways, and remember, with the helper type air bags, you can't shorten....only lift. So it is a moot point anyway.
Did that clear things up KC? Or did I make it worse.
eepwall: