110 from coils to air

[brds]

Hi all.

My 110 V8 is nearly finished now with a new 4.2 engine, Disco transferbox and a ZF auto transmission, hence I need a new project.

Been thinking about putting air suspension on it but without the electronics. Do you know whether the airsprings can be mounted straight into the coil seats of the frame and axle? I know there is an issue with the front shock absorber, but will using a twin front shock absorber turret clear the shock from the airbag?

I have read that quite a few RRC owners have converted their cars from air to coils, but has anyone gone the other way?

What I hope to achieve with the conversion is to have a nicer car on road with a low centre of gravity and the option of raising it to desired height when going offroad.

Thoughts and ideas from the forum on this matter will be appreciated!

Leftover parts from RRC conversions of interest!!

[Jon White]

Only thing I'd say is if you're going to lose the electronics how will you control the ride height and level of it? Air suspension inherantly leaks a little bit here and there, and so will need re-levelling regularly. The rangie by default levels every 6 hours when parked, and every few seconds when driving.

Dont even entertain the use of 2nd hand air springs as they perish badly. Also most 2nd hand compressors will be on their last legs.

The air spring is a direct swap for the coil springs - you need to remove the spring seats on the axles and the air bags clip into the mounting holes. You'd need to sort out front shock mounts as you've mentioned.

Bear in mind also that you will have to limit the drop out travel of the air springs, as they're fixed top and bottom and cannot drop out like coild do. Rangie's also run anti-roll bars - I'd suspect you'd need to run these also.

Finally if you've never driven a rangie on air suspension it surprises a few people how firm the ride is - its certainly alot less comfortable than coils are.

HTH

Jon

[jules]

I have a LSE with all the bits you need even shock turrets. and I have a second set of air spring as well which you could use for the bodies and replace and uprate the air bags

[simonr]

A subject close to my heart!

I added air springs to my 90 a few years back. Then took them off again (I'll explain later!)

I used air bags intended for daf trucks. These have about 13" of useful travel compared to 8" with a RR or Disco air bag. Even a +2" coil spring only manages 9 to 10" travel before it dislocates - so these seemed ideal.

I spent two years building a control system using four pressure transducers and two gyro inclinometers to measure the angle of the body with respect to horizontal.

I used an Air Con compressor to deliver compressed air and used my roll cage as a reservoir.

The control system was designed to try to make the pressure in all the air bags the same. However, if the body leaned by more than 15 degrees in any direction, it would try to bring it within the 15 deg envelope. This coped well with articulation, side slopes and even cornering on the road.

Off road, in it's most active (best) setting, even with the compressor delivering 10cfm @ 100psi, it would only allow me to drive at 4mph, otherwise it started to lag behind - and actually made things worse!

This is what the X-Springs were born out of - realising that all the self leveling & stuff wasn't that useful - but the travel was. That's another story.

On my new truck (still in build) I have gone back to air, on the back at least. Instead of air bags, I'm using FO big pneumatic rams which are more robust - and cos I had some.

All I'm going to have is height adjustability - and I'm going to do that with small valves (possibly push button or lever rather than solenoid) being fed from an adjustable pressure regulator. On the exhaust of the valves will be another regulator.

The idea of this is I can have a high and a low setting on the two regs. These will be set for say on and off road. Then just use the valves to move between the pressures.

The additional thing that rams give you is the ability to pressurise both sides of the piston. Why is this useful? Because, by controlling the pressure on both sides, I can control both the height and rate (stiffness) of the spring. On the road or on steep side slopes, I don't want too much body roll - so pump up the bottom of the pistons which will pull the vehicle down closer to the ground and make the springs stiffer (what you want). De-pressurise the lower ends and the pressure in the top lifts the truck and gives you longer travel, softer suspension.

Air bags generally give you the opposite. When you lower the pressure, the spring rate drops, making the suspension softer (more likely to hit bump stops). When you increase pressure, the truck is lifted, but the rate increases. At full pressure, ti gave something like a 10" lift above standard (which looked funny) but the springs were so solid, the only suspension was in the tyres (a bit bouncy!).

The next problem is that as the spring rate changes, so does the amount of damping required. Don't use adjustable shocks - because these are narrow bandwidth i.e. A given setting will only be right for a narrow range of weights & rates. Most 'ordinary' shocks have up to 12 valves which give different amounts of damping in different situations - increasing the bandwidth of their use. Bog standard ProComps worked much better than Koni or Rancho Adjustables!

There was a window of pressures 30 to 80psi in my case which gave a reasonable combination of parameters. This would effect a 4" lift of the truck from about 1" below standard to 3" above.

If you are interested, I still have two or three of the original air bags available!

Si

Hi all.

My 110 V8 is nearly finished now with a new 4.2 engine, Disco transferbox and a ZF auto transmission, hence I need a new project.

Been thinking about putting air suspension on it but without the electronics. Do you know whether the airsprings can be mounted straight into the coil seats of the frame and axle? I know there is an issue with the front shock absorber, but will using a twin front shock absorber turret clear the shock from the airbag?

I have read that quite a few RRC owners have converted their cars from air to coils, but has anyone gone the other way?

What I hope to achieve with the conversion is to have a nicer car on road with a low centre of gravity and the option of raising it to desired height when going offroad.

Thoughts and ideas from the forum on this matter will be appreciated!

Leftover parts from RRC conversions of interest!!

[steve b]

Hi brds,

There is a company called Ogdenair tel 01274 832613 who do a full kit to replace coils with air bags..I'm just doing a galv. chassis on a 300TDi 110 csw that has this kit with a couple of friends.....not too sure about the control system and wiring as one of the others stripped that all out during the pull down, but its on its way together now so I might be able to find out more soon . From what I've seen there are no hieght sensors just controlled by pressure switching . The bags look similar to what SiR was using , truck axle lift bags , which a mate has used on a 6x6 RRC combined with a manual hieght valve low/med/high off an artic trailer.

cheers

Steveb

[brds]

Only thing I'd say is if you're going to lose the electronics how will you control the ride height and level of it? Air suspension inherantly leaks a little bit here and there, and so will need re-levelling regularly. The rangie by default levels every 6 hours when parked, and every few seconds when driving.

Dont even entertain the use of 2nd hand air springs as they perish badly. Also most 2nd hand compressors will be on their last legs.

The air spring is a direct swap for the coil springs - you need to remove the spring seats on the axles and the air bags clip into the mounting holes. You'd need to sort out front shock mounts as you've mentioned.

Bear in mind also that you will have to limit the drop out travel of the air springs, as they're fixed top and bottom and cannot drop out like coild do. Rangie's also run anti-roll bars - I'd suspect you'd need to run these also.

Finally if you've never driven a rangie on air suspension it surprises a few people how firm the ride is - its certainly alot less comfortable than coils are.

HTH

Jon

thanks for reply.

I was thinking of controlling the airbags using something like this

http://www.arnottairride.com/products/prod...asp?groupId=123

I know it will not give me continous leveling but i think i can live with that.

This company also sells uprated arbags which adress the problem of stiffness at offroadheight

http://www.arnottindustries.com/part_LAND_...yid4_pid21.html

Since I have little or no idea whether this will result in an improved Defender or not I was hoping to use secondhand parts to keep costs down.

I am probably mistaken but besides the tank,hoses and valveblock it should not be to much work to put in (or out again for that matter)

Can I use the shock absorbers to control drop out travel or would I need something else to catch them?

Was thinking of buying a set of +2 shock absorbers for this project.

[brds]

Hi brds,

There is a company called Ogdenair tel 01274 832613 who do a full kit to replace coils with air bags..I'm just doing a galv. chassis on a 300TDi 110 csw that has this kit with a couple of friends.....not too sure about the control system and wiring as one of the others stripped that all out during the pull down, but its on its way together now so I might be able to find out more soon . From what I've seen there are no hieght sensors just controlled by pressure switching . The bags look similar to what SiR was using , truck axle lift bags , which a mate has used on a 6x6 RRC combined with a manual hieght valve low/med/high off an artic trailer.

cheers

Steveb

I will give them a call

Thanks

[Matt Neale]

Couple of things spring to mind (geddit?!)

110 has 7" coils & spring seats on the rear - larger than the fronts (which are common across the rest of the range) - new sring seats shouldn't be a problem but thought I'd point it out as you may have issues with clearance etc.

Also, a few years back there was a Wolf (Defender XD) running around on a suspension system based on rams - I don't recall whether they were hydraulic or pneumatic, but it was called "Kinetic" - and as I recall it worked very well in trials. LRO ran an article on it back when it was more than an catalogue too....

Matt

[brds]

Couple of things spring to mind (geddit?!)

110 has 7" coils & spring seats on the rear - larger than the fronts (which are common across the rest of the range) - new sring seats shouldn't be a problem but thought I'd point it out as you may have issues with clearance etc.

Also, a few years back there was a Wolf (Defender XD) running around on a suspension system based on rams - I don't recall whether they were hydraulic or pneumatic, but it was called "Kinetic" - and as I recall it worked very well in trials. LRO ran an article on it back when it was more than an catalogue too....

Matt

Good point! I did not think of that. Do not know whether it will be a problem. You can put a 90 or RRC rear axle on a 110 surely

[JST]

ref the axle change yes but the salisbury diff has a longer nose so you will need to change props - prob have one made up to suit, although dont the newer 110 have P38 rear axles?

[Diff]

Good point! I did not think of that. Do not know whether it will be a problem. You can put a 90 or RRC rear axle on a 110 surely

Yes but you will need a longer prop as mentioned by James, AND the chassis Spring mount will be too large a diameter for the smaller diameter springs (axle one is easily swapped). Plus the axle from a 90, disco or rangie is not rated for the same weight carrying capacity of a 110 so in theory you shouldn't do it, though I am sure a few have.

Regards,

Diff

[simonr]

You can use the bottom spring cup that you have taken off the rear axle, up the other way, bolted to a spring cup from a 90 as an adaptor at the chassis for the smaller diameter springs.

Si

[Kev Baldwin]

I'm pretty sure, Ogden Air no longer does the kit for the LR.

FWIW. I've ridden in a 90 equipped with a home built Air suspension set up using Air Ride Technologies kit (the same as Ogden were using) shipped from the US and have to say it was without doubt the worst handling POS I've ever had the misfortune to ride in!

[simonr]

I'm pretty sure, Ogden Air no longer does the kit for the LR.

Think you might be right!

FWIW. I've ridden in a 90 equipped with a home built Air suspension set up using Air Ride Technologies kit (the same as Ogden were using) shipped from the US and have to say it was without doubt the worst handling POS I've ever had the misfortune to ride in!

The issue, least the one I found, was that these springs are intended for 7.5 ton trucks. When you run them, even with an unlaiden truck, the pressuer required delivers a spring rate of about 250 lb/in. In a land rover which weighs less, the pressure is reduced and you may only be running the equivalent of a 100 lb/in spring - which is way to soft. That gives good articulation, but leans badly on corners.

The original LR air springs are better because they are smaller volume and give a higher equivalent rate = better handling.

My FO Big rams should be even better for the same reason.

Rear steer in action

Close up of ram

[Kev Baldwin]

IIRC, the air springs this guy was using were from an LDV van. LDV offered air on the rear axles of their ambulance chassis. Having worked at an LDV dealer in the dim and distant past, I know this set up was useless.

[muddy]

I can confirm ogden air no longer sells these kits (hes my cousin )

the airbags he used were off a daf kneeling coach and i always found the ride to be quite good on road , off road he did say they were a little hard. (90 was used for trialing)

his first kit was just manual height controll but he then fitted some (firestone??) sensors to the radius and trailing arms which self leveled the vehicle very well, had a up down button on the dash, so a very similer system to rangerovers ect.

[tacr2man]

Re the ''Kinetic'' army wolf, I saw a 110 csw fitted with this system being demo'd in OZ it just walked over 2foot diameter logs, the articulation was off the planet, also worked as ACE. I think they sold the patent to GM IIRC

[sean f]

I have had air suspension on my 90 for about 5 years now with no problems.

Origionally it was the system supplied from Ogden with a control system from Air-Ride (US company).

It has no auto self leveling but you can check the pressures and once you knew what to expect there was no problem.

I have since removed the Air-Ride control system and added bigger / easier to use switched instead as the air-ride controller was fiddly to use and started getting unreliable. It was designed for the custom car market and isn't realy up to off road battering.

I haven't had any problems with the actual airbags although they are now starting to show a bit of ageing, no leaks though.

As for generally air leaks, it does leak slightly but this is only noticable if I leave it sat for 3 to 4 weeks. It did take some time to chase all the leaks down though at the start.

The suspension travel is limited by the shocks, I can max out 15" travel shock on the rear and bear in mind normally I drive with standard ride height so no real problems with castor angles, etc. Ihave modified to top retainers for the airbags to allow them to slide, the top of the bag can now drop out with a guide to re seat it similar to a dislocation cone type system but with guides for the air supply pipe.

In standard height the ride is not bad, as you lift the vehicle by increasing the pressure the ride becomes progressively harder.

One other usefully thing I have found with the system is the ability to lower the car to connect or disconnect a trailer if the jockey wheel is broken.

[brds]

This sounds very interesting. Could you tell a little more about how you modified the retainers to let the airbags drop out?

Some pictures would be great!

What kind of airbags are you using?

I have had air suspension on my 90 for about 5 years now with no problems.

Origionally it was the system supplied from Ogden with a control system from Air-Ride (US company).

It has no auto self leveling but you can check the pressures and once you knew what to expect there was no problem.

I have since removed the Air-Ride control system and added bigger / easier to use switched instead as the air-ride controller was fiddly to use and started getting unreliable. It was designed for the custom car market and isn't realy up to off road battering.

I haven't had any problems with the actual airbags although they are now starting to show a bit of ageing, no leaks though.

As for generally air leaks, it does leak slightly but this is only noticable if I leave it sat for 3 to 4 weeks. It did take some time to chase all the leaks down though at the start.

The suspension travel is limited by the shocks, I can max out 15" travel shock on the rear and bear in mind normally I drive with standard ride height so no real problems with castor angles, etc. Ihave modified to top retainers for the airbags to allow them to slide, the top of the bag can now drop out with a guide to re seat it similar to a dislocation cone type system but with guides for the air supply pipe.

In standard height the ride is not bad, as you lift the vehicle by increasing the pressure the ride becomes progressively harder.

One other usefully thing I have found with the system is the ability to lower the car to connect or disconnect a trailer if the jockey wheel is broken.

[yellow]

TJ, who works at Nene Valley Offroad near Peterborough, has done exactly this. His 110 (Tigger) has the full air suspension setup of the D2 under the vehicle. The vehicle itself is for sale so if you want to go and check you'll have to be quick. He will be able to tell you more as well

If you manage to go on with this set up, make sure to take plenty of pictures>>>>

[brds]

TJ, who works at Nene Valley Offroad near Peterborough, has done exactly this. His 110 (Tigger) has the full air suspension setup of the D2 under the vehicle. The vehicle itself is for sale so if you want to go and check you'll have to be quick. He will be able to tell you more as well

If you manage to go on with this set up, make sure to take plenty of pictures>>>>

Would like to see it but not practical unfortunately.

[sean f]

Never tried uploading pics so hopefully this will work....

The top of the air spring is attaced to a cup shaped attachment with a tube fixed in the middle, the tube can then slide down through a plate attached to the top of the spring seat, the cup shape (machined to match the spring seat) ensures it sits securely when working normally. The air line runs down the centre of the tube to keep it secure and protected. I was going to fit a retaining ring to the top of the tube to stop it ever detaching completely but frankly the axle can,t drop far enough on the a frame for it to disconnect.