Sanden OBA while keeping A/C; the cheap & easy method

[cbremer]

[font=verdana, arial, helvetica]as you know, one of the more common methods of adding OBA to an XJ while keeping the A/C is to get an open element air filter and moving the battery to the spot previously occupied by the airbox (for me, the intake would have to be CARB-approved, living in CA and all), which also involves lengthening the battery cables. my method requires buying a new battery (Odyssey PC925), but that's it.

all i needed to do was fab up a couple of brackets that hold the compressors together at 4 points, as well as space them apart 1/8" so the pulleys don't rub. i also cut the corner of the battery tray so the belt wouldn't rub. i was able to re-route the original belt while keeping all accessories spinning the correct direction. i completed this little project in 2 afternoons-about 6-7 hours total.

i still need to do something with the upper hose since it's a little more stretched than i'd like it to be, as well as get a steel strap to use as a battery hold-down. also need to wire up a switch near the driver's seat. i'd like to incorporate a tank somewhere- maybe a 2-3' long piece of 3" or 4" pipe behind the front bumper? Right now i'm using it to run my ARB, and to air up tires- it's a little slow on the tires, but not too bad. An air tank should allow me to use air tools (if for only a few seconds at a time )

on to pics:





comments/constructive criticism/suggestions are always appreciated[/font]

 

[BrettM]

huh, that's cool

what are you doing to keep it lubed? I see the zerk fitting.... on my Sanden I am using an air-tool oiler on the intake.

I'm curious to see how you routed the belt while keeping it the same length, could you draw a little diagram?

what battery?

 

[cbremer]

:doh: I used the Odyssey PC925 (edited the original post too)

For lube, i added the Zerk to the oil plug and periodically shoot in some air compressor oil. no problems so far- i was using it for OBA for about a year before pulling that compressor and reinstalling A/C.

As for the belt, i used one of madxj's routings (linked from there- hope they don't mind):

 

[XJZ]

Very cool!! :thumbup:

 

[Roxtar]

Very nice.
I love that it's so obvious an idea that nobody's done.

 

[xtremewlr]

Have you had any issues with the belt slipping when running either the A/C or the OBA compressor? Did you retain the stock idler pulley next to the A/C compressor? I have a spare Sanden compressor and was thinking about doing something similar. I would probably do a remote battery (rear of jeep) instead of the smaller battery as I want to retain my Optima Yellow top.

 

[Kejtar]

how much pressure can you get out of it? And do you ahve any more pics of the setup?

Also by any chance are you going to come to the M&G in Fullerton on Thursday to show it off??

 

[XJ_ranger]

lil off topic, but is anyone runnin the Cadilac suspention compressors for OBA? read about what im talking about here:
http://www.projectxj.com/mods/oba.htm

cool looking idea... with a tank it would work better...

 

[Root Moose]

Very cool.

So you have the same style of bracket between the compressors at all four points?

The diy welder in me wants to weld some brackets between the top and bottom pairs.

Very timely. I was just out looking under the hood over lunch trying to figure out where to stick my ARB compressor - or whether to replace it altogether....

r@m

 

[Roxtar]

:doh: I used the Odyssey PC925 (edited the original post too)

For lube, i added the Zerk to the oil plug and periodically shoot in some air compressor oil. no problems so far- i was using it for OBA for about a year before pulling that compressor and reinstalling A/C.

As for the belt, i used one of madxj's routings (linked from there- hope they don't mind):

The only thing I might add would be to switch the OBA compressor and the AC compressor around if the AC plumbing would allow it. The AC compressor takes more force to turn and this way it would have more tension on the pulley (more belt wrap).

 

[cbremer]

thanks folks for the nice words

to answer some questions- it is tied together at 4 points (top front & rear, bottom front & rear) with the same type of brackets. it's not going anywhere

i have the pressure switch set to cut-off at 125 psi and (with no air tank) it takes about 2-3 seconds to get there. also have a regulator set to 90 psi for the ARB. i have a couple pics of the arb regulator/plumbing, but i didn't upload them yet not sure about the M&G yet...

the stock idler pully is still there (it's not on the diagram, but it does get used). i ran the OBA and A/C with the engine cold, revved a few times, and had no slipping/squealing. i may get a slightly shorter belt simply because the power steering pump is almost at the end of its range of adjustment.

 

[offroadman83]

Very cool. I will have to save this and possibly do it someday. I have no option of losing a/c as we have 100+ weather here and even in december it doesn't get cold here. Right now its 85 degrees here. Have any pics of the brackets you used? Thanks----Kyle

 

[onetallmj]

the stock idler pully is still there (it's not on the diagram, but it does get used). i ran the OBA and A/C with the engine cold, revved a few times, and had no slipping/squealing. i may get a slightly shorter belt simply because the power steering pump is almost at the end of its range of adjustment.[/QUOTE]

Shorter belt?

shouldn't it be longer cause of the extra pulley?

thanks for the tech, I think I am gonna try and do this.

 

[bj-666]

i think this is a great idea but a few things i have to say... what is with the mini bat you must not have a winch or plan on cranking over your engine more than once. and with all that work i would have spent the extra mone on a york that has a crank case like an engine that can be filled and not woried about. all and all it's a pretty good mod. I myself am running the single saden oba version and have not had any problems with the comperssor except for melting a few filters/air hoses.

 

[cyberbackpacker]

The odyssey batteries are quite stout despite their small size. The are multipurpose and are Military grade. Check their history. Hawker/Odyssey batteries. US military uses them in their tanks and such. Deep cycle, dependability, etc. I think for this app, it is a great idea.

 

[Dano]

Have you had any issues with the belt slipping when running either the A/C or the OBA compressor? Did you retain the stock idler pulley next to the A/C compressor? I have a spare Sanden compressor and was thinking about doing something similar. I would probably do a remote battery (rear of jeep) instead of the smaller battery as I want to retain my Optima Yellow top.

I am doing this. Me and a buddy are actualy building a custom sub box to hold the sub in the middle, battery on the bottom and air tank on top, all to kinda look like the spare tire. it will mount in the factory location for the spare. Don't forget you will want to fuse off the Positive battery cable if you move it to the back. wouldn;t want to be in a crash or roll over and than have a fire started by the battery cables.

 

[trailrunner]

looks good,did the same thing on my 99.

 

[Root Moose]

So how is this working out after a couple of months of use?

Just curious.

r@m

 

[STEELFISH]

I too am curious, what belt number/brand are you using? any tank yet? what about belt slipping? I am getting ready to do the same, except relocate the battery...thanks

 

[cbremer]

very happy so far. we've had quite a bit of rain recently here and ran the defogger to keep the windows clear (defroster makes the a/c run) and didn't have any squealing. i also did a run up to the snow a few weeks ago with no ill effects. i had theA/C running (heated, but dry) while airing up and nary a peep from anything. i'm still running the stock length belt with different routing; no air tank so far unfortunately. i couldn't be more pleased with the results of this little project