Is the ARB Twin Onboard Air the best solution?

[Boston Mangler]

I disagree. An ARB dual or my superflo dual will inflate a single tire from 18 to 38 psi in about 3 minutes. But a friend of mine had a pressurized tank and I was able to inflate the same in about 30 seconds. Now, could I have done all 4 tires in 30 seconds? Maybe. If that’s the case then yes the stem would be the limiting factor. But I don’t think it is for any compressor without a pressurized tank

There’s variables

If tank is full when you start, sure, will be faster

But as air in tank depletes, it’s basically like filling a much larger tire with a lot more volume and will take longer

So first tire may be faster, but the rest would likely be slower, unless you wait for tank to fill, etc..

That @TeCKis300 engineer fella can probably explain better than me

 

[Broski]

But a friend of mine had a pressurized tank and I was able to inflate the same in about 30 seconds. Now, could I have done all 4 tires in 30 seconds? Maybe.

No !

 

[Broski]

The best thing a tank is good for is resetting the bead

 

[grinchy]

Apex valve matters more for deflate in my experience. I felt it aired up faster too, but I haven’t done back to back timings.

I’m sure there is a spec somewhere on the volume/pressure curve for a schrader valve. Makes sense to me that number is probably bigger than the 6 cfm or whatever the compressor can provide at 35 psi.

 

[linuxgod]

Were the pressures the same? That would make a huge difference.

We went from 18 to 38 or 40, yeah. I was hella impressed by the tank.

 

[linuxgod]

There’s variables

If tank is full when you start, sure, will be faster

But as air in tank depletes, it’s basically like filling a much larger tire with a lot more volume and will take longer

So first tire may be faster, but the rest would likely be slower, unless you wait for tank to fill, etc..

That @TeCKis300 engineer fella can probably explain better than me

Yeah I’m not sure I’d normally carry a powertank for this purpose. I was just noting that the tank fills much faster than an ARB can, so multiple hoses won’t reduce the total time because the schrader valve and hose aren’t the limiting factor

 

[Boston Mangler]

Yeah I’m not sure I’d normally carry a powertank for this purpose. I was just noting that the tank fills much faster than an ARB can, so multiple hoses won’t reduce the total time because the schrader valve and hose aren’t the limiting factor

Oh.. I misunderstood

I thought you mean an aux air tank connected to ARB dual compressor.

A lot of folks install these and don’t realize it slows it all down after it drains from first tire

Yeah, power tanks are crazy fast

 

[Broski]

Oh.. I misunderstood

I thought you mean an aux air tank connected to ARB dual compressor.

A lot of folks install these and don’t realize it slows it all down after it drains from first tire

Yeah, power tanks are crazy fast

So did I
Power tanks are still limited by what can go the valve and hose.
And have their own limits they run out and have to be refilled = hassle.
At the same time if you have fast OBA you will find your buddy’s wanting to use it.

 

[Boston Mangler]

So did I
Power tanks are still limited by what can go the valve and hose.
And have their own limits they run out and have to be refilled = hassle.
At the same time if you have fast OBA you will find your buddy’s wanting to use it.

I’ve used power tank like products in the past and loved them, but one of the main issues (other than the space they take up) was here in San Diego because of all the hipsters making their “craft IPAs” all our local refill places will only refill with “food grade” co2 and it costs 5-6x what it used to. Nutso

 

[Adrenaline6]

We went from 18 to 38 or 40, yeah. I was hella impressed by the tank.

I meant that the tank pressure had to be way higher than what the compressor provides. If not, the tank would quickly equalize pressure with the tire as it fills it and there would not be enough volume to fill the tire. The only way to have enough volume is to compress more air volume into the tank which would mean higher pressure which would, in turn, mean faster fill rates through the Schrader valve due to the higher pressures.

 

[grinchy]

I ran a little 2 gallon tank for a couple years. It was a little faster overall, as it would pressure up while I walked from tire to tire, so each tire got a little jumpstart at its lowest pressure. It was also handy as I could run air tools for short spurts if necessary. I never did find it necessary to do that though.
The aux fuel tank is a much better use of the space it was in.

 

[linuxgod]

I meant that the tank pressure had to be way higher than what the compressor provides. If not, the tank would quickly equalize pressure with the tire as it fills it and there would not be enough volume to fill the tire. The only way to have enough volume is to compress more air volume into the tank which would mean higher pressure which would, in turn, mean faster fill rates through the Schrader valve due to the higher pressures.

Yeah it was a big scuba tank (power tank). I don’t know the pressure or how many tires it’ll do but @TheGrrrrr does I’m sure. I just know I did 4 tires fast, so those shrader valves can handle a LOT more CFM than an ARB dual can put out

 

[Boston Mangler]

Yeah it was a big scuba tank (power tank). I don’t know the pressure or how many tires it’ll do but @TheGrrrrr does I’m sure. I just know I did 4 tires fast, so those shrader valves can handle a LOT more CFM than an ARB dual can put out

Absolutely

 

[bloc]

It’s pretty simple. If a compressor or power tank can sustain 200psi in the line vs 100 while filling, it’ll fill the tire roughly twice as fast. I doubt an ARB is sustaining even 100. Power tanks start at such a high pressure they can do this easily.

This is even more pronounced as the tire approaches being full, because the percentage difference between the hose and tire is greater.

The vehicle I drive for work needs 120 psi in its ten tires, two of which are 425 section width. They give us a large air compressor at the station but it tops out at about 125. Needless to say those last few psi are really slow. But if I use our “low-pressure” lifting airbag regulator on a 4500psi SCBA bottle and set that near the pressure limit listed on the air hose, which is 300psi…

You better not clip the air hose on and walk away though. (Technically you can’t with the fill valves they give us.)

 

[Adrenaline6]

Yeah it was a big scuba tank (power tank). I don’t know the pressure or how many tires it’ll do but @TheGrrrrr does I’m sure. I just know I did 4 tires fast, so those shrader valves can handle a LOT more CFM than an ARB dual can put out

Yes, but what I am saying is the cfm the schrader valve can handle is related to the pressure applied. The valve can still be a limiting factor, but will flow higher cfm under higher pressure. That is just physics.

The real proof test would be to have someone go from say, 10-35 psi, under the same conditions (tire, compressor, temperature) and time it using a schrader valve, and then time it again using an Apex.

This guy did a video, but wasn't very good on keeping track of times, but the Apex was faster than the schrader valve, which means it is a restrictive factor.


I can try and do a test of inflate times when I have the time to...or maybe @grinchy can do one, since he has the same type of setup.

Nothing better than a proof positive test.

 

[Broski]

I go wheeling to chill and get away from it all, if it takes 30 seconds longer to fill or empty a tire who cares. and you still have to wait for the slowest guy in the group

 

[Adrenaline6]

I go wheeling to chill and get away from it all, if it takes 30 seconds longer to fill or empty a tire who cares. and you still have to wait for the slowest guy in the group

Cool, I get it...you do you, but the discussion wasn't about if you or anyone cares or not, it was about if the valve was a restriction. That's it.

 

[grinchy]

Yes, but what I am saying is the cfm the schrader valve can handle is related to the pressure applied. The valve can still be a limiting factor, but will flow higher cfm under higher pressure. That is just physics.

The real proof test would be to have someone go from say, 10-35 psi, under the same conditions (tire, compressor, temperature) and time it using a schrader valve, and then time it again using an Apex.

This guy did a video, but wasn't very good on keeping track of times, but the Apex was faster than the schrader valve, which means it is a restrictive factor.


I can try and do a test of inflate times when I have the time to...or maybe @grinchy can do one, since he has the same type of setup.

Nothing better than a proof positive test.

Science!

 

[Boston Mangler]

I go wheeling to chill and get away from it all, if it takes 30 seconds longer to fill or empty a tire who cares. and you still have to wait for the slowest guy in the group

This

Yall arguing over minutia

 

[hoser]

Yes, but what I am saying is the cfm the schrader valve can handle is related to the pressure applied. The valve can still be a limiting factor, but will flow higher cfm under higher pressure. That is just physics.

The real proof test would be to have someone go from say, 10-35 psi, under the same conditions (tire, compressor, temperature) and time it using a schrader valve, and then time it again using an Apex.

@linuxgod If you have a valve stem laying around, just turn your twin ARB on compare the output with and without the valve stem. The compressor will be more labored (drop in RPM) with the valve stem. Or, take two balloons and inflate them with your ARB until they pop. One with the valve stem in place and one without and measure the time. But as Adrenaline6 mentioned, the 10-35psi test would be most useful.

Additional info from Morrflate:

The MORRFlate Off Road 4 Tire Inflation Deflation™ Kit • My Off Road Radio

The My Off Road Radio MORRFlate - Inflate, Deflate, and Equalize up to 4 tires. All at one time. Good for any air source. Any size tires. Wheelbases to 155"

myoffroadradio.com