Air Suspension

umbertob

Well-known member
Apr 26, 2007
230
11
Altadena, CA
Better ground clearance than standard coils in off-road height, and a few tricks unique to the EAS system (extended off-road height) may help getting unstuck in certain situations. More comfortable, and with better performance and stability on-road due to lower center of gravity in normal height. More elegant vehicle entry and exit for short legged mammals, especially in access height. Easier to load cargo or connect a trailer with rear suspensions you can raise or lower at the touch of a button. Best chances of fitting inside a low overhead parking structure (locked access height.)
 

ERover82

Well-known member
Nov 26, 2011
3,711
318
Darien Gap
Better ground clearance than standard coils in off-road height, and a few tricks unique to the EAS system (extended off-road height) may help getting unstuck in certain situations. More comfortable, and with better performance and stability on-road due to lower center of gravity in normal height. More elegant vehicle entry and exit for short legged mammals, especially in access height. Easier to load cargo or connect a trailer with rear suspensions you can raise or lower at the touch of a button. Best chances of fitting inside a low overhead parking structure (locked access height.)

Also emulates solid axles with valves that direct air to drop a wheel when the opposing wheel compresses. Self leveling for any cargo or trailer weight. It's all nice until it faults, you need real articulation, or maintaining it.
 
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discostew

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Sep 14, 2010
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Northern Illinois
Departure angles have more to do with your bumpers than whats holding the truck up. The benefits of air suspension have been beaten to shit here on a lot of threads. I would say that one great example is when a spring dislocates and all thats holding that wheel on the ground is the weight of the axle, as apposed to the air spring inflating untill some of the weight of the truck is also holding the tire to the dirt. Towing for sure(not really offroad related)but it helps keep the truck at the correct stance and more than likely helps to improve the tow rating of the vehicle. I'll try to find a link to a very cool video of a Disco built by an ex-engineer for one of those fancy ass Italian shitbox cars. Ferrari I think.

Found it, I think this is a pretty cool truck.

 
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DiscoHasBeen

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Aug 7, 2016
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Indy
Here's my "problem" with it, keeping in mind I live in the mid-west so it's more mud/rutted trails than rock crawling.

Being stuck was almost always a result of bottoming out, but very rarely was it on the frame/body, almost always the differential/hoghead. Enter a body lift (never more than 1") and suspension lift. Obviously that allows for larger tires, which in turn gets the diff more clearance. An air suspension is like doing a suspension lift and leaving the same tires on there. What's the point? It's kind of like Liebig's Law. Where you can go is limited by the lowest point on your rig, which in the case of the new Defender would be the lower A-arms. Look at the 8:08 mark.


So, it's more to make a vehicle that's primary use is as a DD slightly more off-road capable. As opposed to making a rig flat out more trail ready?
 

ERover82

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Nov 26, 2011
3,711
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Darien Gap
My P38 on EAS keeps the wheels on the ground better than the coils on the Disco. I think air is better on and off road.

Air on a solid axle is a bit of a different animal. Don't know much about P38s, but if the valves are cross linked that would enhance the inherent articulation effect of solid axles. There are other factors as well in comparing articulation such as sway bar setup, bushings, geometry, etc
 

DiscoHasBeen

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Aug 7, 2016
901
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Indy
Articulation and keeping the wheels on the ground has its place. But, in my experience, the #1 reason a vehicle ceases to go forward is that it has bottomed out. This would be on one of the lowest hard surfaces of a rig. Mostly either the lower A-arms or the diff. How does air suspension help with this?
 

Harv

Well-known member
You're right if you have bottomed out on the diffs, eg as in very deep mud. In my experience that is not the #1 reason for not going forward. For me it would be climbing loose shaley undulating grades, where articulation is hugely important.
 

discostew

Well-known member
Sep 14, 2010
6,887
685
Northern Illinois
Departure angles have more to do with your bumpers than whats holding the truck up. The benefits of air suspension have been beaten to shit here on a lot of threads. I would say that one great example is when a spring dislocates and all thats holding that wheel on the ground is the weight of the axle, as apposed to the air spring inflating untill some of the weight of the truck is also holding the tire to the dirt. Towing for sure(not really offroad related)but it helps keep the truck at the correct stance and more than likely helps to improve the tow rating of the vehicle. I'll try to find a link to a very cool video of a Disco built by an ex-engineer for one of those fancy ass Italian shitbox cars. Ferrari I think.

Found it, I think this is a pretty cool truck.

Bump for the soft Range Rover Classic dash in a Disco.
 

Tugela

Well-known member
May 21, 2007
4,555
356
Seattle
Articulation and keeping the wheels on the ground has its place. But, in my experience, the #1 reason a vehicle ceases to go forward is that it has bottomed out. This would be on one of the lowest hard surfaces of a rig. Mostly either the lower A-arms or the diff. How does air suspension help with this?

Having just recently taken my new (to me) LR3 off-roading in soupy North Carolina mud, I experienced this phenomenon firsthand and learned something useful: air suspension is superior to a solid axle in muddy ruts. The underbody clearance of my LR3 in off-road height (granted, I also have 265/65/18 tires, which are a little taller than stock) is pretty generous, somewhere in the neighborhood of 11 inches. In extended mode it's a little more. My LR3 sat in the ruts and straddled the ground in the middle no problem.

Behind me on the trail was a 1995 RRC LWB, lifted, with larger-than-stock tires. It got repeatedly stuck, once to the point where even traction mats were no good and I had to extract it with my tow strap. When you looked behind the RRC there was a trench in the ground carved out by the diffs. Sample size is one, but in this case - a literal side-by-side comparison - all the air suspension vehicles on that trip (including stock D5s and LR4s on street tires) easily outperformed a built RRC. Some of that is likely due to Terrain Response vs. the VCU B-W transfer case, but none of the independent suspension vehicles got stuck because they bottomed out. None of them got stuck at all.

About 100 feet further along from here is where I had to tow the RRC. Traction mats helped at this point but later it became too deep.

69052CBD-3B7F-4BB5-AF3B-48B6E16879C8.jpeg

L405 RR on 20"(?) wheels and street tires - no problem.

FA7F3960-4D49-449F-9722-81107B8F1D58.jpeg

(Edited to add photos)
 
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DiscoHasBeen

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Aug 7, 2016
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Indy
I've been watching some vids of the new Defender and I'll admit that when one is going to stay in the neighborhood of stock as to tire size the absence of a diff is a huge advantage.
 

Blue

Well-known member
Mar 26, 2004
9,557
552
AZ
I always laughed at air suspension but I didn't realize the vast improvement in offroad ride quality. Fifty miles on washboards is no longer a grueling endeavor.
 

ERover82

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Nov 26, 2011
3,711
318
Darien Gap
I wish LR would build an independent suspension vehicle that doesn't suck. So much wasted potential.
  1. Remove every complication that isn't necessary to meet regulations. All additional complication should be found in optional packages.
  2. Use a modern platform for weight savings, NVH, and rigidity.
  3. Give it model unique long-travel independent suspension, not a regurgitation of D5 parts.
  4. Use cross-linked airbags to supplement coils, so when they fail, you're not SOL.
  5. At least match the LR3/LR4's cargo capacity.
  6. Retain a somewhat boxy and interesting design.
  7. Don't use touchscreens to control critical functions
  8. 17" is the modern standard for off-road tire selection. Stick to it.
  9. Fix the quality issues.
 
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ERover82

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Nov 26, 2011
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Darien Gap
They’ve built some turds but if you think the L405 sucks I don’t know what to tell you

I'm sure the L405 is a fine RR, but I have no interest in luxury cars or what they do with the RR line. Much more interested in the Discovery and Defender badges.
 

DiscoHasBeen

Well-known member
Aug 7, 2016
901
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Indy
but none of the independent suspension vehicles got stuck because they bottomed out. None of them got stuck at all.

To add, with my CJ7 or Wrangler on 33's I'm not locked into 4x4 there. Could you put 33/35's on any of those air suspension rigs? Maybe if you left them at full extension? What kind of ride would that provide? And how long before you blew out a CV joint or half shaft? So if you want to stay close to stock AS gives you a big advantage, but it also means you have no choice but to stay close to stock.
 
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