convert classic on coils to air suspension

[stevema]

Hi all

Great forum you have here!

I want to do the opposite of what most do and convert a soft dash coil suspension to the EAS system.

Does anyone know whether full kits are available anywhere or if I'd have to look for them used?

How hard is it to do, i.e. is the chassis able to take both or would it need cutting/welding?

Thanks

Steve

[teslo]

I think that buying complete second hand system to have at least chance for success (if you will be able to find one in good condition) It is a great thought but not sure if cost effective. It is very complicated system.

Yes there are some bracket on the chassis for EAS box and pressure tank, but those are easily doable. Sensors require brackets on radius and trailing arms. ECU with bunch of cables is located under RHfront seat.

[g&t]

Sorry to be personal but have you considered psychiatric help? To take something so pure & simple and add a level of complication that so many seek to be rid of. You obviously relish a challenge & I wish you luck, but be aware that your DIY conversion may fall foul of VOSA & have a detrimental effect on re-sale value.

[Snagger]

I think your only chance is to buy a donor vehicle and trnsfer the lot across, but you'll still have to find the soft-dash controls and wiring if you use an older donor. I know of one potential hard dash donor in Luton, static for a few years now, but they might have plans for the vehicle.

[geoffbeaumont]

What's so complicated about it? Okay, it's a good deal more complex than four coil springs (or leafs), but it's not exactly rocket science if you aren't scared of electronics. Most people get rid of it because they haven't bothered to maintain it properly.

It has to be said the version fitted to classics was basically a prototype that Land Rover 'field tested' on their customers, and has some eccentricities (park it on a side slope and leave it running and watch it dance...) - I'm not sure what the legal implications would be, but if I was doing this I'd be tempted to see if I could use the controller from a P38 instead as this was more thoroughly developed and is better behaved (and also gives you a bit more control). I don't think it's tightly tied into the rest of the vehicle electronics like everything else on the P38 - just provides a 12V signal to the BECM and doesn't need anything itself as far as I can remember. You'd still need classic air springs (buy them new, don't reuse them unless you manage to buy a donor that has recently had them renewed - the plungers last but the rubber bladder is a similar construction to a tyre and ages). Not sure if the height sensors are interchangeable. On a P38 the compressor and valves are in a more sensible place up high in the engine bay, but I doubt you could find room for them there in a classic.

On EAS Range Rovers the front shocks are mounted differently as they can't run through the centre of the spring - I'm not sure if the brackets for this will be present? Guess they might be if your vehicle is of an age that it was an option.

All the inputs and outputs are pretty simple, so if necessary you could knock up your own switches for it.

[duncmc]

My 93 model year has all the holes in the chassis to fit everything for air suspension. There aren't any brackets for the front shocks though I don't think.

I like the idea of using a controller from the P38 though, might try that when I get my air suspension one working.

[Jon White]

What year is the RRC? The chassis is the same for coils/air on the later models. If its an earlier model it wont have the brackets probably.

The RRC EAS system is actually remarkably simple and the electronics are very reliable. Once you've got your head round it it actually takes very few inputs so should be pretty easy to retro fit to anything else. Where you may struggle is if its an earlier model you may not have the necessary wiring in place.

I would have air again without a doubt. I think the only reason people take it off is becasue it has become fashionable to do so, or becasue people cant be bothered to take the time to understand the system and to maintain it properly. The air bags do have a finite life, but if these are replaced, the rest is pretty reliable (as reliable as anything else is on an RRC anyway). With EAS unlocker you can maintain and diagnose the system yoruself without having to resort to paying a garage for diagnostics. (I suspect this was one of the reasons people got rid of it in the past).

Jon

[g&t]

Reading the last couple of posts I am reminded of why I love to just drive the thing & keep it maintained as factory original, but of course it's a case of 'each to his own' - though I still stand by my remarks re VOSA & it would be interesting to see what your insurer's reaction will be.

[Bowie69]

I can't, knowing a fair bit about VOSA, see why they would be interested at all?

Insurers yes, as it is a modification, but you aren't modifying the chassis in any way so....?

[sean f]

Easiest way is to fit an aftermarket controller, loads of valve blocks on the market if you want full manual control, I have had this on my 90 for over ten years now, with a 4 way valve block and 4 toggle switches one to control each corner. Just look at the american custom market, generally they are used to make low riders but the same kit can run a longer air bag and away you go. Just need a compressor of some sort, again plenty about at various prices and qualities.

For more ease of use there are set ups that use ride height sensors so can be programmed (easily) for various ride heights, other systems use air pressure instead.

I have just converted my P38 to use an aftermarket controller, nice and small control screen which fits in the new dash easily, rest hidden away in the back. I had to go this way as the P38 has none of the origional wiring left and was on springs when I re-engined it, losing nearly 500kg of weight meant it rode very high and hard, air springs sorted that.

Hardest part you might find will be mounting the air bags, not to sure of the changes in the chassis, with a bit of work and mix and match of parts I expect it could be done, rest is quite easy.

[Jon White]

The downside with the aftermarket system however is that you dont get the automatic load levelling, plus also the speed related suspension lowering etc.

Jon

[g&t]

I can't, knowing a fair bit about VOSA, see why they would be interested at all?

Insurers yes, as it is a modification, but you aren't modifying the chassis in any way so....?

May be I've used the wrong title, what I meant was the MOT. As for insurers - surely a total suspension spec. change is going to raise a few eyebrows? I'm sure many on here will remember a certain 110 crash resulting in 3(?) drowned kids in Lincolnshire a few years ago - an event which probably did more harm to the 'modified 4x4' scene than anything previously seen.

[Bowie69]

Err, yes that is what I said, for insurers it's a notifiable modification and likely to put the premium up.

MOT wouldn't bat an eyelid, they just test as the vehicle is presented, if they are concerned about anything, they can note it in the advisories free text or if they consider it dangerous, refuse to test, but a conversion well-done or to factory later spec wouldn't be a problem.

[Aragorn]

Even for the insurers, its not really any different to someone whos taken a airsprung rangerover or disco and refited coils when the system has broken, which must be fairly common?

[simonr]

I would go for it!

And strangely enough, I did: http://www.x-eng.co.uk/Sproklegrommet/LRSuspension/Index.asp

If I did it again, I would change a few things.

1. Use one of the off the shelf after market suspension valve blocks - mine ended up costing more, being less tidy and more leaky.

2. Use Standard Range Rover Air Springs. The Firestone ones are fine, but the spring rate is proportional to the air pressure, as is the height. If you set the height to something sensible, with the big bags, it gives you an equivalent rate of about 30 Lb/in - very soft and it will hit the bump stops all the time. The original bags are sized to give you the right spring rate at normal ride heights.

3. Don't build as complicated controller! All it needs is an Up/Down switch for each air bag. You don't need pressure gauges etc as you can feel when it's not right.

If you want self leveling, make it like a Pinzgauer which just uses switches to determine when the suspension is too low or high with a 'dead band' between the high & low switches. If one spring is too high, it vents some air until it's not. If it's too low, it opens the valve to put more air in until it's not. You need to restrict the flow in and out and make the dead band wide enough to provide some damping. If not, driving along a bumpy road will be accompanied by the sound of valves frantically clicking and air hissing and the air bags shooting up & down.

For adjustable height self leveling, you could use four control cables (bicycle brake cables) to move the positions of the switches up & down with respect to the axle. Connect all four cables to a single control lever in the cab.

This gives most of what I had without any electronics. Granted, you have to change the ride height lever depending on where you are driving - but you can generally make a more informed decision than the computer. You might be driving fast over bumpy ground and want enough travel not to hit the bump stops - or driving very slowly along a side slope and want it sitting as low as possible to minimise the centre of gravity.

If you added an individual adjustment screw to each cable - you would be able to trim the lean of the vehicle from inside the cab.

Si

[simonr]

Quick sketch....

[Snagger]

Even for the insurers, its not really any different to someone whos taken a airsprung rangerover or disco and refited coils when the system has broken, which must be fairly common?

Don't fool yourself - the specialist like FLux and Sureterm will add a premium for it, but the run of the mill insurers won't permit it. Look at the faff I faced with fitting a snorkel to my wife's 90 - LR describe it as an accessory, but the insurers insist it's a mod and unacceptable.

[simonr]

Don't fool yourself - the specialist like FLux and Sureterm will add a premium for it, but the run of the mill insurers won't permit it. Look at the faff I faced with fitting a snorkel to my wife's 90 - LR describe it as an accessory, but the insurers insist it's a mod and unacceptable.

Is this the new equivalent of the SVA Police? Instead of 'dont do it because it will need an SVA' there now seems to be a rash of 'don't do it because your insurer won't like it'!

For me at least, the whole point of a Land Rover is that they are fun to modify - Meccano on steroids. If I wanted something that I was not going to play with - I could have something more comfortable and more economical for the same money! However, I have a Td5 Defender and I like modifying it - so probably always will!

Si

[geoffbeaumont]

If it's a completely standard classic RR system then there shouldn't be an legal issues at all (though it'll still be a notifiable modification for insurance purposes), as it's all type approved for the vehicle anyway. Standard I am not a lawyer, over-rider on that opinion, of course!

Like Si, the main reason I would run a Land Rover is because I can tinker with it (yes I know a Corsa with a well wikked body kit would be cheaper to run, but you've got to have some standards...).

[sean f]

As Si says a standard aftermarket controller is fine, works well and simple to install and run.

The control system after that can be as complicated or as simple as you like, on my 90 it is 4 two way switches, one for each corner for a totally manual system.

After market controllers will have nice switches and air pressures for each corner displayed, they are normally capable of being setup to automatically set the air to a predetermined pressure and have programable pressures for different setups, as pointed out this means it won't automatically level the vehicle if a load is placed in the back although this can be done manually quite easily. More complex (expensive) systems use ride height sensors pretty much as Si describes but pre made and setup for universal mounting, these can be setup for a series of preset ride heights at the press of a button, with a bit more complex control they can also be used to make the car dance about if you want to show off. To the best of my knowledge none of them will give the automatic ride height changes that the factory system would, I expect some one with the right electrical knowledge could work out how to do this but not me.

As Si says unless there is a good reason to do otherwise stick with the standard air bags as they will fit easier and have the correct rate for the vehicle, I fitted firestone bags on the 90 as they gave extra travel, I can max out 15" shocks quite easily, the shocks now limit the travel with the air bags securely fixed to the axle and a dislocate sytem installed at the top end which only rarely comes into play. The P38 is standard bags and shocks all round but an aftermarket controller.

I have declared all the mods and never had any problems with the insurance for the air suspension but then again virtually nothing else is "standard" either so both vehicles are on custom policies anyway. The 400HP LS1 engine in the P38 was more of an issue than the aftermarket suspension controller!!.

[simonr]

To make it even simpler - you could use a toggle operated 5 port air valve mounted similarly to the switches I've drawn above. Each time the toggle hits one of the end stops it lets air in or out of the bag until it hovers in the middle. There are commercial valves that work exactly like this for trucks - but I imagine they are more expensive.

Use something similar to the control cable idea to implement adjustable height - and you have a fully controllable setup with auto leveling and no hint of electrickery!

Si

[Snagger]

Is this the new equivalent of the SVA Police? Instead of 'dont do it because it will need an SVA' there now seems to be a rash of 'don't do it because your insurer won't like it'!

For me at least, the whole point of a Land Rover is that they are fun to modify - Meccano on steroids. If I wanted something that I was not going to play with - I could have something more comfortable and more economical for the same money! However, I have a Td5 Defender and I like modifying it - so probably always will!

Si

Don't shoot the messenger Simon. I like tinkering as much as the next man and hate most insurers' negativity, but as legal as the mod is, it's going to be a pain if he can't subsequently insure it at a viable price. I'm not saying don't do it, I'm just saying to check the financial ramifications first. Please get of your high horse now.

[jad]

There was a grey double cab 110 or 130 defender I think in one of the magazines that converted to air suspension but not using standard kit. Might be worth a read if anyone knows the issue. It was an LRM or LRO.

Jad

[Snagger]

I remember a grey 90 with air suspension too, and the owner had it all adjustable from the cab to set each wheel independently, giving better side slope ability amongst other things. It was very impressive.