OBA -> On Board Air Mega Thread & BS

nice install.... well thought out.

 

Just started seriously looking into my own OBA setup (odd my autocorrect wants to change oba to Obama?). I want to be able to fill tires at the end of trails and have future plans for rear ARB Locker.

I see a lot of people using Viair and other 100% duty cycle compressors, but from what I'm seeing they have lower CFM (<2) than other "medium duty" compressors. Is this strictly for using air tools or is there something I am missing. Higher CFM = faster tire/tank fill.

For instance I was comparing ARB to MV90. Granted the MV90 has a much higher amp draw.

specifications MV90
rumored 67% duty cycle
air volume: 6400 cubic inches per minute
CFM at 90 PSI: 3.71
maximum voltage: 12 volt
maximum amperage draw: 45 amps
maximum working pressure: 150 psi
maximum restart pressure: 90 psi
maximum operating temperature: 90 degrees F
minimum operating temperature: -67 degrees F
maximum continuous operating time: 40 minutes @ 40 psi @ 75 degrees F

 

In order to accurately compare the CFM outputs, find each manufacturers chart for the CFM rates at PSI. Then you can tailor the best fit for your needs and air tools you want to run. (Max psi, CFM requirments etc)

 

Yes, you need to compare CFM at say 90PSI for both compressors. I am using a Viair systm with the relay/limit swithc rated to turn on at 90PSI and turn off at 125 PSI (they sell one higher and one lower). If you use a tank of 3 to 5 gallons capacity in your OBA system it will go a long way toward topping off your tires. The pitfall here is if you have really small compressor and a really large tank you will have to wait a bit for the tank to build up if you drain it below say 60 PSI.

Any way you go it sure beats driving around on 12PSI on the road hoping your tires dont overheat! I used to never go below 20PSI so that I could drive home as is, but in many conditions lower pressure is a big improvment.

 

For anyone it may concern, i used up the last bit of my CO2 tank this weekend airing up. this was the first cycle from full to empty that i had run through it. i was curious how acurate the "tank pressure" gauge would be, and it turns out that it is extremely acurate. lost pressureprecisely when the needle hit empty. this is in refference to the power tank brand. i cannot speak for to the acuracy of any other brands.

 

Subd

 

Got home from work and started installing this behind the rear driver side seat.


drilled and tapped into the floor on top of the foam pad that is already there and bolted it down, ran the electrical to the dash gonna finish up tomorrow. Went with the twin for future lockers, air up the tires and run some small air tools.

 

I am picking up my ARB Twin air compressor on Friday and will be installing it in my tool box. Do any of you know what fittings I would need to run it through the wall of my tool box so I can have access to a quick Disconnect on the outside?

 

Sounds like you need a bulk head fitting, or a PTC straight if you'll have enough thread sticking through to attach a female quick disconnect.





So many options, What size air line are you running?

Preferred is a DOT rated PTC fitting.

 

I haven't got any airlines for it yet.

Also via some googling it appears that I will be needing their air manifold so I can run my locker with the twin. Ugh so damn annoying.

 

Twin doesn't come with the manifold?

 

Nope for some reason it doesn't.

 

Thought I read that the manifold comes with the locker?

 

My locker did not come with a manifold, but I did buy my locker and compressor at the same time and the non-twin compressor comes with the manifold, so I highly doubt the lockers come with the manifold.

They do come with the solenoid (and wiring/switch for it) that goes into the manifold and allows the lockers to air up selectively.

 

Thats what I probably saw

 

I picked up a tank today. I just need the mounting straps for it. Anyone have a place they can point me to for two 9.75" diameter straps?

 

Commercial truck parts stores might have them for the tanks used on air brake systems. Not sure what size they are though .

 

Ya actually the tank came off of a bus (front brakes) I tried looking it up but most of them were like $65 and up plus shipping (some were even up to $300 for them mounts). Seems a little steep for a thin piece of metal. It's 9.75" in diameter btw.

 

Where are you going to mount yours?

 

Under the bed where the spare was. Probably closer to the cab or where ever I have the most room/clearance.