38 replies to this topic

[SubaruWagon87]

Is there a thread on how to convert an ea82 ac compressor to be an air compressor for on board air? Or is there a write up somewhere? I tried searching, but the search wouldn't look up "on" and "air".

[monstaru]

bratsrus1 has done this.i do not think thee is a thread.

i just got some air compressors off of some 80's cadillacs that had air ride and put a bigger alt on.the drag the compressor makes on the engine is worth getting rid of.just a thought.cheers, brian

[gwilson87]

I am looking at the process of turning my ej22 engine in my brat into on board air. As for write ups... google will give you better results than anything here. Lots of rock crawling jeeps do the conversion. I am going to convert mine with help from a crawler buddy. Including a 5 gallon tank where my spare tire used to go.

[Phizinza]

You need to just fit air fittings to the aircon unit. The inlet side needs a filter and the outlet side needs a moisture trap. You also need to make sure it has oil in it, and some of that oil will get caught in the moisture trap so you'll need to empty that and top up the compression every so often.

[The Scooby]

i know that its cool to have on board air but how many times will you use it. if only a handfull then i recomend just get a power inverter that plugs into the cig lighter and converts it to 110v then run a small 1gallon compressor in the back. alot easier to move around, don't need to rigs anything up and you can move it between cars.

[Yo'J]

Air lift or "Air Ride" suspention! 3 wheel cornering and hoppers! Drive high and park low. No one can steal your car if its on the ground!

[Phizinza]

Here in South Australia we have lots of sand so going 4wding often means you let the tyres down to around 7-10psi. A small cig lighter pump takes about 10mins a wheel to get back to road pressure, that's 40mins waiting and by then if you didn't let the pump cool down its fried (yes, we have fried a pump like that before. I rebuilt it and it worked again but not as well). With my brothers York (Range Rover) compression he could inflate a 27x8.5R14 tyre in 40seconds. Or one of his 35x12.5R15 tyres in a min 30.
If I didn't have aircon in my car, I'd use the pump as a compressor for sure. But for now I'll just rely on someone else or a fuel servo nearby

[The Scooby]

im not saying to use those cheap cig pumps. here in the states you can get a power inverter that you plug into the cig lighter and ups it from 12v to 110v.

then just have a normal compressor to plug in and use to air up the tires.

[Yo'J]

I have not yet found a good way to run 15 amps (compressor startup) out of my car without a second battery, solenoid, alt upgrade and a converter worth real change. (I want a skill saw) The aircon unit pushes like 200lbs, regulated to 150lbs and the thing wont sweat. Its already there and there is plenty of aftermarket stuff like adaptors and hoses. My neighbor runs his airbags off his with a 3 gallon tank and it works just fine. You hit the controller and pop! It will make you bounce in your seat and its like a 2ton+ car.

[Steve W.]

Why not go to one of the air ride suspension outfits? Theve got some pretty afordable compressor systems, with suprisingly high CFM, and no need for an inverter. S.

[gwilson87]

Possibly a compressor hooked up to a power inverter would be easier, but honestly, where is the fun in that? It may not be the most practical thing to convert the AC to air but it is unique and fun. I for one know I will use it pretty often with mountain biking. I might not be airing down my tires but I bike a lot and it would be nice to have the air right there when I need it. I can't wait to get my swap done so I can start on this.

[Phizinza]

cig lighter plug has 10amp fuse, 10 amps at 12v is only 120watts, where are you going to find a 110v compressor that is any good that only uses 120watts? Plus it is all just much more weight. A belt driven compressor is relatively light weight compared.

Edited by Phizinza, 29 June 2009 - 01:46 AM.

[TheSubaruJunkie]

Good luck running an air compressor for long off a power inverter. Unless you buy a real expensive inverter.

A/C pumps are the easiest way to make alot of air quickly. And cheap. You should look for a York air compressor. they have a piston pump with an enclosed crankcase that has the oil. The air traveling through the pump does not need to be lubricated, but it does need to be filtered.

You can find these pumps on ebay fairly cheap. Might have enough room to mount em somewhere on a EA81.


Right now, I use a portable pump that plugs into my cig. lighter. Im about to convert it over so it clips to the battery itself instead, and wire up a second battery. This is all for my 4Runner however, which I air down quite frequently. And airing a single 35" swamper from 8psi to 35psi can take quite a long time!

This is why I cannot wait to rig up a better onboard solution!

[SubaruWagon87]

I've been doing some reading on using a york for on board air, and it seems to me like the most logical choice. Yeah, stock a/c compressors bolt in, but you have to run another filter to filter out the oil from the air being compressed, but I want a challenge. And from the looks of it, I can build an on board air system for around $100 or less.

[TheSubaruJunkie]

I have been slowly building all the pieces I need. I have $0.00 invested so far, and I have a 5gal tank (two 2.5gal tanks side-by-side). All the hose & fittings I should ever need. Including a 1 - 100 psi guage for mounting pretty much anywhere. Also a few switches that are pressure controlled to do some cool things with

Just gotta find me a good york on the cheap, and make the brackets.

[SubaruWagon87]

Heres a pretty good list of what compressors came in what car: http://www.dakuda.co.../yorkchart.html

[Yo'J]

Boy those subaru ac units look alot like a york style one.

[NorthWet]

I have a 12v portable compressor, a high-volume/medium pressure (100-120 psi) that attaches to the battery with "alligator" clamps (like a battery charger). Compared to typical battery-powered inflators, it quickly pumps up my tires, and only cost me about $35USD (on sale) at Harbor Freight Tools. And it comes in its own case.

[TheSubaruJunkie]

I have a 12v portable compressor, a high-volume/medium pressure (100-120 psi) that attaches to the battery with "alligator" clamps (like a battery charger). Compared to typical battery-powered inflators, it quickly pumps up my tires, and only cost me about $35USD (on sale) at Harbor Freight Tools. And it comes in its own case.

PSI is one thing.

CFM is another. (cubic foot per/min)


CFM is what we are after. Sure you can get that $35 pump to build up to 120 psi (mine will do it too). It just takes forever to do so. Its because the volume of air it is able to pump diminishes the higher the compression gets. I paid $90 for my pump (has a nifty bag too) and i believe it pumps at 1.1 CFM at 0psi. But once it reaches near 30psi it is only pumping at .7 CFM, and if it were to ever reach 100psi, it would be close to .3cfm


I think when I was doing some research on the Yorks they can pump something like 3.3 CFM at 50psi and that is depending on the RPM given to the pump.

[FlyB0y]

You know, I have toyed with the idea of converting my AC compressor, but I have few air tools, and although I think it's a great mod, I am curious, how often do you have to oil the comp. if you just use the stocker? I have one that was stock on my brat still, and I would lover to just put in a filtered intake on one side and a dryer/water trap on the other.

I don't air up and down much since now I have separate ATV tired I switch to, and yes I used to store the ATV tires where I had to air things up and down with a cheap Walmart cig lighter compresser and it hasn't got hot or let me down, but it takes FOR-EVER to air up a set of tires, I figure it took me around an hr to do the deed lol!

[gwilson87]

From what I have read you have to have the oiler setup always since the AC compressor uses the refrigerant to keep it oiled. I found a few write ups awhile back about how to turn any stock AC compressor into an air compressor, but it wasn't top of my list so I lost track of them. I knew I should have bookmarked those...

[FlyB0y]

Ahh yes I remember reading that somewhere too, and it's just a simple in-line oiler that can be bought for air tools, probably a cheap on at HF would work. I might have to get a tank going too and get serious once I get all the rust off ... HF seems to get a lot of stuff for projects started for me, but I often start more than I can do lol!

[gwilson87]

Yeah my wife doesn't like it when I got to HF because I see all sorts of stuff I "need". My brat is enough of a project for me right now. But on-board air would be really fun and useful for me. Yeah we all could just use the electric stuff, but honestly, where is the fun in doing something the easy way

[FlyB0y]

Yeah, I know what you mean, maybe in my case it would be GOOD to have a wife to tell me not to buy something ... I knew there was at least ONE good reason to get married .. j/k hehe.

My last trip there was just to get an airline dryer/water separator for $15 and I came home with a new tow strap (with-out hooks to replace my damaged one with) and a cargo holding bar for the bed. I really think the new recovery strap was needed, and the bar will make hauling my off-road tires much easier, just I always end up spending 2-3x what I planned there.

[Yo'J]

So I guess you just need to plumb in a oil filter, to get the oil out of the line on its way to your storage tank and plumb the discharge of that into a small oil retainer like on a nail gun (maybe not a plastic one as they get hot in a car) put the "self oiler" on the pump side of the air filter and if you run your air bags every day (if you have air ride suspension) you might want to check it every week or two. Then you can just run the compressor and bleed it to the oil retainer. The oil is only for the piston. Same for a york.

This is what is running my neighbors air bag suspension system. He is using a york, every day. Its about the size of a gallon of milk but taller and on a v8.

I forgot, your controller, pressure cutoff and on switch.

Edited by Yo'J, 14 July 2009 - 12:10 AM.
duh...turn on....