[Gerg]

A question for those who are running the York OBA. Where the heck are you putting air tanks, or are you running any tank at all?

Also, is there a pressure relay that contorls the on/off for the clutch?

Pictures of the tank location and configuration would be appreciated.

TIA,

Greg

[ONE JEEPBRO]

Here is a link to a guy here on the forum who did a full OBA setup. Pretty good job in my opinion and answers your question on where to mount the tank.

http://www.ohiomurals.com/jeepin/oba.htm

[Jerry Bransford]

Like most who installed an air tank with their York-based OBA system, mine is mounted underneath the Jeep between the frame rails. It's on the driver's side, between the driveshaft and frame rail, just to the rear of the transfer case. No worries about being damaged on the trail, I don't think I've ever heard of a tank getting damaged there. You definitely want an air tank or the compressor will have to run all the time, plus the air tank can provide a lot more air volume for a short while at those times you need it like reseating a tire bead or for running air tools.

Yes you will definitely need a pressure switch to shut the compressor off when the system pressure reaches around 115 psi and turns it back on at around 80 psi. You can get a pressure switch from Brad Kilby at www.onboardair.com/ or Graingers. Some switches are pretty big, I prefer the smaller type that is around 2" long and 1/2" in diameter. Sun, who also makes a very popular 2.5 gallon air tank, sells them too. Actually, I'd recommend Sun at http://www.sunperformance.com/ over the others since they carry the nicer small switch and air tank. Go for the #PS001 air pressure switch that has the smaller 1/8" fitting since it has better psi settings. You'll need a 1/4" to 1/8" adapter for it but that's easily found.

[Gerg]

Thanks Folks, Trying to plan ALL the things I want to do so I don't have to do stuff twice!

[E_ROCK]

Originally Posted by Jerry Bransford

Like most who installed an air tank with their York-based OBA system, mine is mounted underneath the Jeep between the frame rails. It's on the driver's side, between the driveshaft and frame rail, just to the rear of the transfer case. No worries about being damaged on the trail, I don't think I've ever heard of a tank getting damaged there. You definitely want an air tank or the compressor will have to run all the time, plus the air tank can provide a lot more air volume for a short while at those times you need it like reseating a tire bead or for running air tools.

Yes you will definitely need a pressure switch to shut the compressor off when the system pressure reaches around 115 psi and turns it back on at around 80 psi. You can get a pressure switch from Brad Kilby at www.onboardair.com/ or Graingers. Some switches are pretty big, I prefer the smaller type that is around 2" long and 1/2" in diameter. Sun, who also makes a very popular 2.5 gallon air tank, sells them too. Actually, I'd recommend Sun at http://www.sunperformance.com/ over the others since they carry the nicer small switch and air tank. Go for the #PS001 air pressure switch that has the smaller 1/8" fitting since it has better psi settings. You'll need a 1/4" to 1/8" adapter for it but that's easily found.

Just a pic in the the same place that Jerry is talking about. Sorry for the huge picture.

[Jerry Bransford]

Wow that tank seems huge, its diameter is a lot bigger than my Sun 2.5 gallon tank's is. It looks like it might hang down well below the frame rail, does it?

[DigDug]

Originally Posted by Jerry Bransford

Like most who installed an air tank with their York-based OBA system, mine is mounted underneath the Jeep between the frame rails. It's on the driver's side, between the driveshaft and frame rail, just to the rear of the transfer case. No worries about being damaged on the trail, I don't think I've ever heard of a tank getting damaged there. You definitely want an air tank or the compressor will have to run all the time, plus the air tank can provide a lot more air volume for a short while at those times you need it like reseating a tire bead or for running air tools.

Yes you will definitely need a pressure switch to shut the compressor off when the system pressure reaches around 115 psi and turns it back on at around 80 psi. You can get a pressure switch from Brad Kilby at www.onboardair.com/ or Graingers. Some switches are pretty big, I prefer the smaller type that is around 2" long and 1/2" in diameter. Sun, who also makes a very popular 2.5 gallon air tank, sells them too. Actually, I'd recommend Sun at http://www.sunperformance.com/ over the others since they carry the nicer small switch and air tank. Go for the #PS001 air pressure switch that has the smaller 1/8" fitting since it has better psi settings. You'll need a 1/4" to 1/8" adapter for it but that's easily found.

Mini-hijack here (sorry in advance):

I was just wondering what advantage the 2.5 gallon tank gives you... Are you guys using air tools or just airing up tires. I was thinking about putting one in just for the tires and it doesn't look like it'd help that much (maybe my math is messed up).

2.5 Gal = .334 cubic ft at 14.7 psi (1 atmosphere)

pump that up to 120psi and you get: 120/14.7*.334= 2.7 cuft

Without going through all the pi*r^2 times width calculations a 33" tire (1/2" of tread, 1/4" sidewalls) holds 10.4 cuft at 35psi and 4.4 cuft at 15 psi leaving you 6 cuft to pump up each tire after wheeling.

You've got 2.7 in the tank but you can only use 85 psi of the 120 (it stops when the pressure in the tire equals the pressure in the tank).

By quick ratio calculations it looks like you'll get about 21 psi in the tire before the pressures equal... and that's just one tire... You got 6 psi or about 1.8 cuft out of the deal... I guess that saves you a minute with a smaller compressor (what's the york's CFM rating?) but then you have go from 21-35 with just the compressor, and wait for the tank to fill before the next tire (I guess walking from one tire to the next could take a minute or so)... so for a 1.8cfm compressor you're saving 4 minutes I guess (if it takes you a full minute to move from one tire to the next)...

Okay.. enough geek crap...

What advantage do you see to installing a 2.5 gallon tank? Is my math wrong, or are you guys running tools or something? Maybe it's useful to have 120 psi instantly available for re-seating beads?

[Jerry Bransford]

It provides an extra reservoir of high initial air volume which helps get the tires inflated much faster. The compressor runs after that initial volume is used up but the York gets it refilled very quickly (you don't have to wait) for the next tire. The compressor puts out enough air volume that it refills the tank very quickly. The tank speeds up not only the tire refilling process but helps run air tools that require larger air volumes than the compressor could keep up with. The typical intermittent air tool usage allows the compressor to keep up when a tank is present but it could not without the air tank. This is why even the very small air tool compressors have air tanks, as small as they are... and very often even smaller than the 2.5 gallon tank we use most commonly in our Jeep OBA systems.

[E_ROCK]

Originally Posted by Jerry Bransford

It provides an extra reservoir of high initial air volume which helps get the tires inflated much faster. The compressor runs after that initial volume is used up but the York gets it refilled very quickly (you don't have to wait) for the next tire. The compressor puts out enough air volume that it refills the tank very quickly. The tank speeds up not only the tire refilling process but helps run air tools that require larger air volumes than the compressor could keep up with. The typical intermittent air tool usage allows the compressor to keep up when a tank is present but it could not without the air tank. This is why even the very small air tool compressors have air tanks, as small as they are... and very often even smaller than the 2.5 gallon tank we use most commonly in our Jeep OBA systems.

http://www.truckspring.com/airsprings/firestone/product/9126.asp

It doesn't hang down. The picture is just decieving. I also take air tools on runs with me. I can tell you how much I love having an impact on the trail. Without an air tank, you couldn't run an air tool.

[DigDug]

Originally Posted by Jerry Bransford

It provides an extra reservoir of high initial air volume which helps get the tires inflated much faster. The compressor runs after that initial volume is used up but the York gets it refilled very quickly (you don't have to wait) for the next tire. The compressor puts out enough air volume that it refills the tank very quickly. The tank speeds up not only the tire refilling process but helps run air tools that require larger air volumes than the compressor could keep up with. The typical intermittent air tool usage allows the compressor to keep up when a tank is present but it could not without the air tank. This is why even the very small air tool compressors have air tanks, as small as they are... and very often even smaller than the 2.5 gallon tank we use most commonly in our Jeep OBA systems.

Roger that on the air tools... they require very large volumes of air, but for very short bursts, with (ususally) a good recovery time in between... An impact wrench runs for maybe a second or two, then sits idle while you move to the next bolt/lug and the compressor fills the tank. Gotta have the tank for that...

For filling tires, once that initial burst is spent from the tank (120 psi down to the tire's pressure, 21psi for 33's in my math), you're limited by the ability of the pump to re-fill the tank... basically the air is going straight through the tank into the tires. So you save 1.8 cubic ft of "compressor time" on the first tire... (one minute for a 1.8cfm compressor - a slow one)

Then I take 1 minute to cap off the valve, check the pressure and walk to the next tire, the compressor is still running, pumping 1.8cfm into the tank so it's full again by the time I get to the next tire.

Repeat the process...

I guess what's sort of happening, is that I'm "filling the tires" while I'm capping off and moving to the next one... I save 4 minutes for a 1.8cfm tank. If you've got a faster compressor you save less time.

Don't take me as arguing, I'm just trying to figure out if it'd be worth it for me to put a 2.5 gal tank in. Right now I'm only looking at airing up (no tools... yet!!!) and the math says it saves me 4 minutes for a 1.8cfm compressor, 33" tires, and a 2.5 gal tank. I'm just looking for some real world experiences to validate my geek think...

Has anyone filled their tires both with and without the tank? How much of a difference does it make? 4 minutes is a pretty good savings... What I'm thinking is that after I buy the tank, mount it, the pressure switch, the hoses, etc... I will have spent enough money to get a 2.6cfm compressor instead of a 1.8- which would make up the time difference. (Although air tools might be nice )

[What The?]

Originally Posted by 1jeepbro

Here is a link to a guy here on the forum who did a full OBA setup. Pretty good job in my opinion and answers your question on where to mount the tank.

http://www.ohiomurals.com/jeepin/oba.htm

Glad my writeup helps a little (even though it's old). I've modified the wiring a bit since then, but it's pretty much the same setup as what I wrote. Yeah, I agree with the others. the 2.5 gal tank is great for getting a head start on filling up the tires, and giving you a little extra air as you go between tires. Although it's not needed if you are just using OBA for tires, you really might as well add it on.

I use mine for impact wrenching, and I can really lay on the wrench for a good 20 seconds before the pressure goes down too low. I suppose it depends on your wrench. I also use the tank for my air horn, which is instant bursts of air when you really need it.

[Diehard]

Originally Posted by Jerry Bransford

Like most who installed an air tank with their York-based OBA system, mine is mounted underneath the Jeep between the frame rails. It's on the driver's side, between the driveshaft and frame rail, just to the rear of the transfer case. No worries about being damaged on the trail, I don't think I've ever heard of a tank getting damaged there. You definitely want an air tank or the compressor will have to run all the time, plus the air tank can provide a lot more air volume for a short while at those times you need it like reseating a tire bead or for running air tools.

Yes you will definitely need a pressure switch to shut the compressor off when the system pressure reaches around 115 psi and turns it back on at around 80 psi. You can get a pressure switch from Brad Kilby at www.onboardair.com/ or Graingers. Some switches are pretty big, I prefer the smaller type that is around 2" long and 1/2" in diameter. Sun, who also makes a very popular 2.5 gallon air tank, sells them too. Actually, I'd recommend Sun at http://www.sunperformance.com/ over the others since they carry the nicer small switch and air tank. Go for the #PS001 air pressure switch that has the smaller 1/8" fitting since it has better psi settings. You'll need a 1/4" to 1/8" adapter for it but that's easily found.

How is the pressure switch hooked up to the compressor. Any set up diagrams? Thanks.

[E_ROCK]

Originally Posted by DigDug

Roger that on the air tools... they require very large volumes of air, but for very short bursts, with (ususally) a good recovery time in between... An impact wrench runs for maybe a second or two, then sits idle while you move to the next bolt/lug and the compressor fills the tank. Gotta have the tank for that...

For filling tires, once that initial burst is spent from the tank (120 psi down to the tire's pressure, 21psi for 33's in my math), you're limited by the ability of the pump to re-fill the tank... basically the air is going straight through the tank into the tires. So you save 1.8 cubic ft of "compressor time" on the first tire... (one minute for a 1.8cfm compressor - a slow one)

Then I take 1 minute to cap off the valve, check the pressure and walk to the next tire, the compressor is still running, pumping 1.8cfm into the tank so it's full again by the time I get to the next tire.

Repeat the process...

I guess what's sort of happening, is that I'm "filling the tires" while I'm capping off and moving to the next one... I save 4 minutes for a 1.8cfm tank. If you've got a faster compressor you save less time.

Don't take me as arguing, I'm just trying to figure out if it'd be worth it for me to put a 2.5 gal tank in. Right now I'm only looking at airing up (no tools... yet!!!) and the math says it saves me 4 minutes for a 1.8cfm compressor, 33" tires, and a 2.5 gal tank. I'm just looking for some real world experiences to validate my geek think...

Has anyone filled their tires both with and without the tank? How much of a difference does it make? 4 minutes is a pretty good savings... What I'm thinking is that after I buy the tank, mount it, the pressure switch, the hoses, etc... I will have spent enough money to get a 2.6cfm compressor instead of a 1.8- which would make up the time difference. (Although air tools might be nice )

Are you talking about an electical compressor? I think most engine driven A/C compressor put out more than 2.6cfm. It they are more like 4.

[Jerry Bransford]

Originally Posted by Diehard

How is the pressure switch hooked up to the compressor. Any set up diagrams? Thanks.

It works just like an on-off switch so just wire it in series with the clutch solenoid wire. By the way, wire an additional regular on-off toggle switch in that same series so the compressor only turns on when you need it.

[DigDug]

Originally Posted by eelson

Are you talking about an electical compressor? I think most engine driven A/C compressor put out more than 2.6cfm. It they are more like 4.

I'm talking about a hypothetical compressor... You get to use 1.8-1.9cf out of a 2.5 gallon tank before it's pressure matches the tire's pressure (with my example of 33's) and the tank becomes useless for that fill. With a 1.8cfm compressor you save exactly one minute filling your first tire with the tank -vs- without (see my geek math above). With a faster (higher cfm) compressor that time savings goes down quite a bit... that's what I was asking... for simply filling tires, is it worth it to add the tank or would you be better off spending the cash on a bigger compressor?

For pure speed I think I might find a used CO2 tank and build my own CO2 system and carry one of those cheap pep-boys compressors as a backup...