Onboard air: Best bang for your buck?

4speedhandler

TJ Enthusiast
Original poster
Joined
Apr 19, 2016
Messages
172
so i've looked around at a lot of options for onboard air and went through a few stages:
1) dont know much, better research
2) these look good but lets see what else is out there
3) damn i want it but thats too much
4) these all look good so how do i chose

where im at right now is stage 4 of the progression and want to hear what other people have in the way of electric compressors/air systems. not really interested in one of the AC compressor conversions so i'd love to hear anyone's input on the arb, viair, or other similar systems. it will be used for airing up 37's and operating my rear arb.
 
CFM (cubic feet per minute) is KING where important specifications go for OBA systems. To be a really useful compressor for refilling our Jeeps's big tires, you want something at least 2 CFM or higher. And be wary, many CFM ratings are totally misleading, like the CFM rating given by Smittybilt.

In order for CFM to be a valid useful rating, the air pressure that CFM was achieved into has to be included with the CFM rating. A CFM rating into 0 psi will be useless, as that 0 psi rating meant there was no resistance against the compressor. Your lungs can probably put out 10 CFM into the open air but 0 CFM into a tire. So you want a CFM rating that says it was made into some pressure, like 20 psi. That means it can put its 2 CFM rating into a tire that has 20 psi of pressure pushing back... a useful way of knowing just how powerful the compressor really is and if you'll need only 5 minutes to refill your tires or 45-60 minutes to refill your tires.

That Smittybilt I mentioned brags it can put out 5.65 CFM... which is HUGE. But that's not how much it can really put out in actual use when airing up a tire... their 5.65 CFM rating is into 0 psi, totally misleading. Given its size, I'd guess its honest CFM rating is maybe 2 CFM at the most.

My best advice is to buy the compressor with the highest CFM rating you can afford, just make sure that CFM rating is an honest one... look for what pressure it was rated again. ARB and Viair compressors are known good quality compressors. I'd avoid anything sold in an auto parts store, Smittybilt, etc. Ignore inexpensive compressors whose biggest claim is an extremely high PSI rating... even a bike hand pump can achieve high psi into a small bike tire, I had a hand pump for my road racing bike that could pump a tire up to 120 psi relatively quickly... but that tire was extremely skinny and didn't hold much air. That same bike hand pump that could achieve 120 psi in my road bike tires would probably take 2 hours to pump up my 35" tires to 25 psi.

On my previous TJ (stolen), I converted a York belt-driven a/c compressor which put out a LOT of air... probably 7 CFM if I raised the engine up just off idle. I miss that OBA system, it even drove air tools very easily. For my replacement TJ, I put together a CO2 system using a 10 lb. aluminum tank. It works well, it puts out around 5 cfm, I just have to remember to refill it every 5 trips or so.

Hope that helped. :)
 
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This is a little copy and paste from another post I made some time ago. I installed the ARB compressor on mine. I took the tray out and drilled holes in the tray to match the compressor, then tightened the compressor to the tray. Then installed it and the tray together. With the screws loose on the compressor, it articulates nicely to install it. Then set everything at the angle I wanted things and tightened the screws on the compressor. I wrapped teflon tape around one of the hole caps the factory packs the compressor with to plug into the air hose socket, works great to keep dirt out.
Now in real world use. I only have 33's. I was able to put 15 lbs in and it took about 3 1/2 minutes, so just under 5 lbs a minute, not sure what it's rated at. I'm good with that. However, on 37's I can see that time waiting could be annoying. I wanted to keep my system multi duty, lockers/tires. There just isn't much room in the 2 door TJ and I want what I can get for other things I need to carry.
I went at this thing for a quite a while when I was setting up my tire deflators. I finally overheated the compressor and it shut off for a bit. But, it took me about 45 minutes of continuous use to do it. I'm going off memory here. In a normal refill I didn't overheat the thing and was able to refill all four without stopping.
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thank you both for your input, do either of you have specific models of electric compressor you would steer me towards as above average quality? hoping to spend maybe $300 max but im not totally sure how feasible that is for a capable enough compressor.
Jerry i see you mentioned cfm ratings, i havent seen many listed on the sites i have browsed so far is there some sort of reference guide on a website or forum that you know of somewhere i could check out?
 
I put together a CO2 system using a 10 lb. aluminum tank. It works well, it puts out around 5 cfm, I just have to remember to refill it every 5 trips or so.
I was in the same place you are a few months ago and did what @Jerry Bransford did. Cost was well under $300, actually closer to $225-250 if I recall, just have to spend $10 to get it refilled at the local welding shop every so often.
 
A reliable onboard air system is not cheap. I went with the ARB CKMA12. I do also add a 2.5 gal tank and have never run into overheating or other issues. I do run 33 x 10.5 and my gal 33 x 12.5 We refill both sets with probably no cool down time in between most of the time. Keep on mind that I was looking for reliability not speed filling.
I was looking into Viair as well, nice product that many of the Club member has. Just went with ARB due it fits very nice on the tray below the master cylinder.
Got mine from 4wd online during a monthly sale event. Just take it easy and shop around for both ARB and Viair, you will find a good deal.
I do add the ARB Technical Specs comes with my pump, hope it's help.
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i should have looked closer on the manufacturers websites it seems. thanks for the guidance guys.
as of now it looks like a viair 450C would be the best bang for my buck using the viair constant duty system from quadratec and then just source a smaller tank to fit somewhere conveniently, add an air dryer and call it good.
 
i should have looked closer on the manufacturers websites it seems. thanks for the guidance guys.
as of now it looks like a viair 450C would be the best bang for my buck using the viair constant duty system from quadratec and then just source a smaller tank to fit somewhere conveniently, add an air dryer and call it good.
Be sure to always check pricing on other sites like Amazon, Google Shopping, etc. since Quadratec's pricing is well known to be higher than most other sites. They will price match but that's totally unfair to the retailers who price lower to begin with.