D.I.Y - Air Ride on mk3

[c00k 435]

As air ride is becoming more popular and cheaper, thought i would put up afew tips on bagging mk3's,
will also work on mk2's and corrado's as well as there the same suspension.
and easily adapted for mk1's, 6n 6n2 polo, loads of Seats, few earlier Audi's, etc.

There are many off the shelf kits you can buy, if you want something you can just buy and fit straight to your car.
Rayvern Hydraulics,
Plush automotive
Air Lift,
Bag yard.
Air rex.
just to name a few.

But this is a if you want to build the struts, and most things yourself keeping the cost down

Front Air Bags,
On the front there bag over coilover,
they are Areo Sport bags, I bought mine from the US as there much cheaper,
there about £375 a pair in the UK, but from US there £210 a pair, plus postage and import tax.


you also have to buy or make some simple plates to fit the bag on to the coilover.



(heavy duty bearing are inside the small bags)

The bolts to fit the plates are UNC thread, the size I can't remember but I will look it up if anyone needs it.
once the plates are fitted the air bag will now slide over the coilover shaft.
I flipped the coilover rings, so the flange that held the spring in place before, is now facing down wards.
Giving a flatter surface for the bottom plate of the bag to sit on.

you will either need to run counter sunk allen key bolts, or file some of the coilover ring so the bolt head fits in.
same of the airline line fitting, you will need to file away some of the coilover ring so the airline fitting has enough room.

Be careful when fitting the coilover with front bags to the car, you can NOT run any camber, as it will make the bag rub the inside of the turret, causing the bag damage and it will split up over time.

I cant stress how much you need to check the clearance on the front!! between the air back and the inside of the turret.
check, check and double check again!
last thing you want it to have to buy new front bags again, from them wearing through. soo check full lock, both ways, and check both front bags, and both turrets. if needed file the mounting holes bigger (where the hub bolts through the coilover), so you can pull the bag more away from the turret.... or another way of doing this it to get solid adjustable front mounts.



Rear Air Bag / Struts
Rear bags are Air Lift - universal chapman strut kit no. 75592 not many place advertise them for sale, but if you message them they can usually get there hands on them...
I got mine from US same time and place as the front bag, and there about £310 for the pair. Not sure you can even buy them in UK.
you can't run bag over coilover on the rear it will rub the turret, as the bags are to wide, you have to run a sleeve type bag!


Then the rears need a MK3 mount welded on to the bottom, they come ready to be welded, so you don't need to cut the air lift one, but you will need to cut a mount off some old MK3 rear struts to weld on to the bottom....

I cut about 200mm up the strut, then weld the 200mm inside of the tube that comes with the air lift, then weld all of that on to the bottom of the airlift struts. It just an added bit of extra strength.

All welded up ready for painting




Front and rear built up ready to fit.



Valves,
you can run either 4 of these or 8 of these..


4 valves will give you just front and rear . inflate and deflate.
where 8 valves will give you individual wheel, so you can do front and rear, side to side, individual wheels, 3 wheeling etc. Also with 8 valves you will get better handling, as with only 4 you can get what called bag transfer, and thats where the air from one bag, moves back down the air line and in to the opposite bag on other side, causing the car to lean more. This happens while cornering. Simplest way to cure this is to run an 8 valve system. there are other way if you do want to run a 4 valve system.
As for buying valves, you can get them off eBay or many places, there just solenoid valves, for gases. Some state there just for liquids and water, avoid theses. But if it say they will work with gases, or compressed air they will be fine.
Your looking for ones that are able to hold about 140-160psi, you can go for a higher rating if you wish, but minimum is about 140psi!
Then on the size of the valve, the bigger the valve, and more air it can move, and the quicker the car will inflate and deflate.
1/4" is the smallest I would go
3/8" is a inbetween.
and 1/2" is the biggest.
1" valves are far too big! and may to put to much air through at one time, and cause bag to damage by over filling!

I went for 1/2" and had to slow it down with some flow control devices, as i found it to fast..
but some people like it that fast, i don't as it touches the lips on wheels and i don't want them damaged.

4 Valve set-up (you will get bag transfer with a setup like this)


8 Valve set-up


Air line,
Same again the bigger or wide air line the faster it will inflate and deflate, as the more air it can move.
I went for 10mm O.D air line, most people use either 8-10mm or 3/8"

Tanks,
Smallest I would go is a 3 gallon tank, the smaller the tank the more the compressor will be on, as you haven't got as much air to use, so it has to re-fill more often,
I run 2x 2.5 gallons, so 5gallon total. some people even run 8-10 gallon, but you would need 2 compressor then.
150psi minimum rating for tank, can go higher rating if you want, i went for 200psi, even thou i run a 150psi system to be on the safe side.

Compressors,
Any 12v compressor will work so long as it can get up to 150psi
some of the common one used are Viair and Zen-air, there most probs 2 of the best.
bigger the compressor faster it will fill tanks.

Dials,
(to read the psi in bags, to know how high or low you are)
You will need either 4 dials, or 2 dual needle dials, so you can read the psi in each bag,
Optional if you fit another one to tank to get reading of tanks as well.
Again dials must be able to go up to 150psi or higher
There are also more expensive digital PSI screens.

Fittings,
Most of the are NPT thread, and can't be bought locally, they all have BSP as thats what commonly used in the UK.
But you will find most air tanks, both the front and rear bags, and the valves will be NPT thread,
theres quite afew place on the Internet in UK that sell them.


Switches, (to control the inflate/ deflate)
There's many controllers you can buy and just wire up.

Or you can buy 3pin or 6pin momentary switches.
They must be momentary so as soon as you stop pressing the switch it stops inflating or deflating.
So you need a momentary on off on switch with either 3 or 6 pins on the rear.

If you want to control individual wheels you will need 4 switches one for each bag. (8 valve system)
If you only want to control front and rear you need 2 switches. (8 or 4 valve system)

But you could have 2 switches to control front and rear for when driving, then another controller box to do side to side, individual wheels somewhere else or on a lead for when parked up (8 valve system)

You can also link up wireless fobs, xbox controllers, playstation controllers almost anything if you can get your head around the wiring.
I have a wireless fob on mine, and wasn't to hard to wire up.


Water Traps
These are optional, but are used to remove any excess water vapor still in the air the compressor has sucked in.
The reason you don't want water in your air system is. 1. It will sit in the bottom of your tank, and most tanks are made out of steel, so they will rust from the inside. 2. In very cold weather it can freeze. Yes you can get the same stuff as lorry drivers use in there air brakes to put in your system, to stop it from freezing.

Check Valve
A one way pressure sensitive valve. So it will let air in to the tanks from the compressor but not back out. Plus it will not slowly leak back out the compressor, while the compressor is not in use.

Pressure Valve
Also know as a blow off valve. You will want one that is lower PSI rating than the PSI rating of your tank. This is in case of over filling, or a faulty compressor that gets stuck on. The pressure valve will release the excess air, and will stop the tanks from bursting with to high pressure.
I have 200psi tanks, so I have a175psi pressure vavle. and a 150psi compressor cut off.

Pressure switch
This is different to the pressure valve. It is a sensor/switch that tells the compressor when the tanks are up to pressure and when to turn off. It also tell the compressor when the tanks are too low on pressure and to switch back on.

Drain Plug
This should be fitted, in the lowest possible port in the air tank. Most air tanks have one port on the under side meant for a drain plug.
It's so you can drain your tanks in-case any water has gotten past your water tarps. If running a water trap I would drain them every 6-8 months.
If not running a water trap, I would drain it every 3-4 weeks.


Hards lines, Nylon line, Dot Line, Braided line?
All different types of air line.
Hardlines, either made out of copper or aluminum piping, they are robust, and can cope it alot of pressure. Down side it they don't work very well the Push to Connect fittings, they do work, but are not the best. The metal will usually score the inside seal, causing air leaks from the scoring. So it's best to either braise them, or use compressing fitting.

Nylon line, not really meant for car uses, but you can use at your own risk. Pluses are easy to cut, works well with push to connect fittings. But there are alot of down side. soft an easily damaged. Single layer. Kinks and folds very easily, causing air blockages or bottle necks.

Dot Line, Fully car approved, made for air systems on cars. Cost more, but is double layered. so alot less chance of air leaks. very robust, very hard to kink or fold. If used with DOT fittings almost guarantee 100% leak free system. (This is the type of line a range rover with OEM air bag would run, buses, commercial vehicle, etc)

Braided line, The most expensive type of line, but by far the most robust, and can be moved about, without any leak. Usually triple layered.
So ideal for front bags, because of the steering, and the front air bags moving back and forth alot.

Different Types of Fittings?
Push To connect Fitting, these are for nylon or dot air line, you just push the airline in to it and it seal on the outside of the airline with a rubber or plastic seal, also has very small metal teeth to keep air line in place, also know as PTC fitting.

Compression fitting, these are only needed if using hardlines, they will not work with nylon or dot line. They are commonly used in pluming, but the thread type on the fittings plumber use are different to almost all air ride stuff. Pluming use BSP thread, and air ride stuff is NPT Thread (Some commercial air con equipment is NPT thread). The reason you want the correct thread is to get a nice air tight seal. Using incorrect thread can cause major air leaks.
Also when using threaded type fittings I would recommend using either PTFE tape, or jointing compound. If using PTFE tape, make your you put the tape on in the same direction as you would tighten the thread. So it will pull tighter, and seal nice when doing up the fitting. So it's not trying to unwind, or come loose. Common sense really.

Dot Fittings, abit like push to connect fitting, but with an added extra sleeve that goes inside of the airline that also has a seal. So it's kind of double sealed, on the outside of the air line, and on the inside. These are the best type of fitting, and easiest to get leak free, but should only be used with Dot airline.
There are also many more types of fitting, but these are the 3 most commonly used.


I bought the front and rear bags (you have to message him about the rear) from Newmatics in the USA, he also has an ebay page, and you can change the dollars to pounds to see British price.

Website - http://www.newmaticsinc.com/
ebay shop - http://stores.ebay.co.uk/newmaticsinc


Any questions I will try and help,
I'm no expert but I have bagged 2 of my own mk3's, several friends mk2's and a mk4


 

[VR6Pete 1,455]

This is awesome and worthy of a sticky

[Gefstar 1]

c00k brings it again... top work fella

[Daverse 175]

Great writeup, I think (for me anyway) air ride is still a bit cautious and best left to the experts, but reading shows there's not that much to it. Would love to have a crack sometime at it.

[VIW28 29]

Very good write up! I had a Rayvern setup on mine but glad I went back to coilovers tbh

[michael5556 247]

Can I ask why gethin? I've got wietecs but was going over to air once we sort out this problem I'm having lol

[VIW28 29]

The rear strut design with Rayvern has the wrong geometry, it relies too much on the shock with not enough resistance for the rear end squat that a car with a bit of hp has. Think the likes of Airlift is better and those Chapman ones look better too.

[c00k 435]

Yeah i have also heard afew bad things about rears of raven set up.

it not just on mk3's either, it's also same problem on mk4's and bora's

They are Air Lift mate...

Air Lift universal Chapman.

Plus they have adjustable damper with 9 different setting

Chapman is the design and type of strut it is, originally made by Colin Chapman.

even standard suspension on the rear of a mk3 is a Chapman strut style.

The fronts as standard are a MacPherson strut.

One of my friends mk2 we bagged with the same set-up runs a supercharged VR. about270-280bhp and it handles sweet on them

keep and eye out for it this show season, late spec black mk2, all cream interior, VR supercharged on air tucking some wide BBS RS's.

it's just been in Golf plus+ without the air set up, that literally just been fitted!

[VIW28 29]

Awesome, learn something every day! Will look out for the mk2 also

[Gregsyb 4]

This is awesome!

Nice write up

[Squizvr6 0]

Did you have to do the body chop on your mk3 to get it to drop tight to the floor!?

[c00k 435]

added a little update to my original post.

just with types of air line, types of fitting, and a few extra bits that are worth buying.

[DanChave 98]

Great stuff

[dom.joy 87]

Massive bump but where did you run the air lines for each corner?cheers