Retrofitting D3 / C5 air suspension in a D2
 

Afternoon all,

I've been looking into air suspension kits for a D2 and it would appear that there is no off the shelf solution available from the likes of Airlift etc etc - I'd most likely have to go the custom route and source parts to make a Frankenstein setup.

This got me thinking - I previously had a C5 Allroad which was equipped with a factory air set up, probably not too different from those found in D3s and onwards (in a raw sense).

I can't find related topics here so I wonder if anyone has had the same idea and even gone as far as successfully retrofitting Audi air suspension from other vehicles to their D2?

Just a thought at the moment but I have a spare unused Wabco compressor and can source the struts and airlines needed to carry out the basic install. There would need to be some custom parts made up but it'd be pretty neat to have OEM parts added to my old girl, rather than aftermarket!

Funnily enough I was thinking the exact same thing while poking around my Allroad. Then I read up on the system and decided coil springs were the way ahead :D I've seen a couple done with aftermarket kit. Its not that hard really - the front struts are the same design as A4 and A6, albeit taller. The rears are perfectly suited to take a standalone bolt-in bag, and are much the same design as C5, C6, or mk4 rears.

If you wanted OE parts you could almost certainly use the front struts from an Allroad. They are taller than the other C5 models so likely would suit the D2 setup. I think the D3 units are too large in most dimensions, although haven't actually measured one. They just look bigger.

D3 rears wouldn't work as that has the spring and damper combined in to a strut whereas the D2 has them separate. The D2 body is not reinforced in the right places to switch to a strut either.

However... the C5 A6 FWD actually had the option of air on the rear beam for self-levelling, and that uses the same style separate spring / damper setup as the D2. The C5 spring is shorter than the D2, but you could easily make some aluminium collars to adapt it to suit. The only downside is cost as you'd not find those secondhand so would need to buy new.

Regarding control, I would immediately discount trying to integrate factory electronics. The Allroad system is complicated enough, connected to pretty much every drivetrain system in the car, but its a blunt instrument compared to the quantum-physics grade complexity of the D3 system. I would suggest aftermarket control is the only practical way to go with that, integrating an OE pump and reservoir, possibly also valve block, with a dedicated & standalone control unit hidden in the armrest. The Allroad button won't fit a D2 dash btw.

Thanks for the comprehensive reply MikkiJayne - glad to hear I'm not the only one who has pondered this!

I'm seeing a company soon to sort out my audio install (double din related trickery proving too taxing for me to want to deal with) - they're a leading specialist in aftermarket air suspension and will be looking over the car for components which might be up to the task so I'll report back if they're able to build me a kit to suit the D2. Would certainly save the faff as it'll come with a suitable management system and likely be engineered with sympathy to the original structure of said car (within reason - I haven't yet found a kit under £4k which is specifically designed for this vintage of A8!).

I know the Allroad system is a bit of a messy one but I thought at the time it was a bit of a marvel, but as you say there would invariably be a lot more involved in harvesting a set up from elsewhere in the marque to get it to work on a totally different chassis with different load temperaments.

As for buttons, I have a friend who is able and willing to 3D print some fresh ones to go in place of my 3 blanks on the dash (top right, can't even explain what would go there) - ideally I'd like:

- Lowest height ('aired out' as the yoof say)
- Driving height
- Highest height (for clearing obstacles etc)

I've priced up Arnott bags, a valve block and ancilliaries at around £2k so there is potential for saving on parts, but labour and 'getting things to fit' is where I see the trouble lying.

Time (and bank balance) will tell...!

Ooh 3D printing buttons is a great idea +++ The blanks are for parking sensors (does yours not have them at all??), rear blind, and rear headrests.

Any air ride specialist should be able to build a setup for a D2 in no time.

The thought does occur that since I'm transplanting my Allroad 2.7 biturbo engine in to my other S8, along with its ESP system, its air ride system probably wouldn't know the difference if that came along for the ride. Hmm.... :D

This is an A6 FWD rear bag:

http://i.ebayimg.com/00/s/MTIwMFgxNj...tY7-l4/$_1.JPG

It'd just need adapters making to fit the D2 body and lower arm, but I reckon its about as close to fitting as any OE part. Bad news is they're about £350 each!

Check out www.bagriders.com for some ideas!

Mk1man has done quite a few air suspension installs on VAG cars also 👍

There also use to be a company called 'Bagyard' who did a kit for the D2. Looks like it went to the wall. :(

Search Bagyard on the forum and a few posts will come up.

This ones on air:
Stanceworks/Rotors8/

...complete with shopping list of bits at the end of the article

I like his carbon fibre wrap console