Great post N.Y.X. OBA is on my list. Some questions for you:
1. I don't see a check valve between the compressor and the tank. I thought one was needed in this location.
2. How did you settle on a 2.5 gal tank? Judging by the aux air port on the bumper you use your OBA to air up. How big are your tires and much time does it save?
3. Where did you get your custom swivel-head hoses?
Thanks!
The long tube off the compressor might have the back flow preventer/check valve in it to prevent compressor damage from tank pressure.
Generally...a small tank can be pressurized more quickly than larger one, but, has less reserve volume, and for 33's, you need about a 4.5 gallon tank at 150 psi to do ONE tire from say 15 psi to 35 psi or so.....so the tank size is mostly for a head start on tire #1.
If the priority is getting back up to a given PSI, the smaller tank is typically preferable (Air tools like ~ 90 psi for example). If the priority is to have a lot of reserve capacity for lower pressure (Filling tires for example), then a larger tank is preferable.
I am assuming that the two compressor solution is a way to speed up the repressurization/compensate for the smaller tank volume, etc.
The Viar 380C is a high duty cycle pump, so it can pretty much run continuously (Within reason...), and using two of them would give a
combined total flow of ~ 1.4 CFM at 140 psi, ~ 1.8 CFM at 90 PSI, or ~ 2 CFM at ~ 40 psi, etc.
As most air tools use 3 CFM or more, this means that they really don't have the capacity to keep up, and, the small tank means that they'd need to run constantly and would still fall behind by more than a CFM per minute.
IE: An air wrench to spin off lug nuts with normal rest between nuts/tire changes, etc...would be about the upper limit of extended tool use it would be able to handle.
If intended for tires, a larger tank would help a lot given the slow refill limits.
As the 380C has a 200 PSI limit, if the tank could hold 200 psi, and the pressure switch set to allow it, etc...the added PSI would effectively increase the stored air capacity.