• RME Gear & Apparel

NAPA 12-Volt Dual Air Compressor (MT-WM102-15C)

Stephen

Stephen

Who Dares Wins
Moderator
Location
Never Far From Nowhere
There has been a lot of discussion regarding the NAPA 12-Volt Dual Air Compressor recently in another thread. Since its a neat little compressor, I thought that I'd spin off a new thread to talk about it more.

I currently have an ARB CKMA12 single compressor which I've mounted in a tool box with an expansion tank to make a poor man's CKMP12V2, essentially.

IMG_6871.JPG
It's worked well and I have no real complaints other than it's slow when filling up my 35 x 12.50 tires. Because of the purported speed, the NAPA 12-Volt Dual Air Compressor was super interesting for the price. So @bobn and I decided to buy a couple of them.

IMG_6874.JPG

We've all watched the video's by Dirt Lifestyle on the Youtubz which highlight how easy it is to hotrod one of these compressors. And honestly, because I love tinkering with stuff, that was a big appeal to getting one. But first I wanted to benchmark it against by ARB. We aired one of my tires down to 15psi and then aired it back up to 50psi using each compressor. These were the results:

ARB Single: 7:51
NAPA Dual: 2:36

That's basically a third less time. That's damn impressive! I'd honestly be happy to just run it as is with that time savings. But that's also super boring!

Dirt Lifestyles video's show that you can really go crazy with the modifications, but I think there were a few key things he and other have done that will get this compressor into the sweet spot for me. They are:
  • Re-lubricate the cylinders with high quality lubricant
  • Replace the circuit board (which is really chintzy) with a relay
  • Upgrade the battery connection cables with 4ga wire and better alligator clamps
  • Install a pressure switch (70-100psi)
  • Drill out larger holes in the air cleaner caps for better air intake
  • Install two quick connect 1/4 NPT high flow couplers (using the existing manifold) so I can go to two tires right out of the compressor
I think that these pretty simple upgrades will help with longevity and really make a this thing fly. I've got all the parts sitting on my work bench, its just a matter of finding the time to put it all together. Once I do, I'll post it all up and what the results are.
 
Kevin B.

Kevin B.

Not often wrong. Never quite right.
Moderator
Location
Stinkwater
Mine is still in the mail, but several of those mods are on my list. I'd like to pair it up with an air tank similar to what you did with your ARB, I'd like to mod the power cables with an Anderson connector so I don't have to mess with alligator clamps, and I'll be adding a pressure switch as well.
 
Stephen

Stephen

Who Dares Wins
Moderator
Location
Never Far From Nowhere
Kevin B. said:
Mine is still in the mail, but several of those mods are on my list. I'd like to pair it up with an air tank similar to what you did with your ARB, I'd like to mod the power cables with an Anderson connector so I don't have to mess with alligator clamps, and I'll be adding a pressure switch as well.
Click to expand...
I thought about the Anderson connector, but I'm airing up other people frequently enough that it's just easier to have the alligator clamps. But who knows, #futuremod!
 
P

Pile of parts

Well-Known Member
Location
South Jordan
Stephen said:
There has been a lot of discussion regarding the NAPA 12-Volt Dual Air Compressor recently in another thread. Since its a neat little compressor, I thought that I'd spin off a new thread to talk about it more.

I currently have an ARB CKMA12 single compressor which I've mounted in a tool box with an expansion tank to make a poor man's CKMP12V2, essentially.

View attachment 169095
It's worked well and I have no real complaints other than it's slow when filling up my 35 x 12.50 tires. Because of the purported speed, the NAPA 12-Volt Dual Air Compressor was super interesting for the price. So @bobn and I decided to buy a couple of them.

View attachment 169097

We've all watched the video's by Dirt Lifestyle on the Youtubz which highlight how easy it is to hotrod one of these compressors. And honestly, because I love tinkering with stuff, that was a big appeal to getting one. But first I wanted to benchmark it against by ARB. We aired one of my tires down to 15psi and then aired it back up to 50psi using each compressor. These were the results:

ARB Single: 7:51
NAPA Dual: 2:36

That's basically a third less time. That's damn impressive! I'd honestly be happy to just run it as is with that time savings. But that's also super boring!

Dirt Lifestyles video's show that you can really go crazy with the modifications, but I think there were a few key things he and other have done that will get this compressor into the sweet spot for me. They are:
  • Re-lubricate the cylinders with high quality lubricant
  • Replace the circuit board (which is really chintzy) with a relay
  • Upgrade the battery connection cables with 4ga wire and better alligator clamps
  • Install a pressure switch (70-100psi)
  • Drill out larger holes in the air cleaner caps for better air intake
  • Install two quick connect 1/4 NPT high flow couplers (using the existing manifold) so I can go to two tires right out of the compressor
I think that these pretty simple upgrades will help with longevity and really make a this thing fly. I've got all the parts sitting on my work bench, its just a matter of finding the time to put it all together. Once I do, I'll post it all up and what the results are.
Click to expand...
Thanks for posting this. I'll be watching, and most likely be picking one up and modifying as well.
 
BCGPER

BCGPER

Starting Another Thread
Location
Sunny Arizona
bryson said:
I'd like to hard mount one under the hood maybe - wired direct to the battery. I have a single ARB set up in the rear quarter panel of the LC80 currently, but it's slow even on a good day.
Click to expand...

As I learned the hard way, this is a very bad idea. Most compressors of any quality will have a built in thermo switch. After a day on the trail your compressor will be too hot to operate. I bypassed the switch on my Viair, but I’d imagine it had a very short life running it that hot. I sold the LJ not long after that so I don’t know for sure.
 
Stephen

Stephen

Who Dares Wins
Moderator
Location
Never Far From Nowhere
I had some time this weekend to finally work on my compressor. Here is what I've done:
  • Took the cylinders apart and cleaned them up. One side was way over lubricated and the outlet to the manifold was about 75% clogged with the goopy lube. I wiped everything down and put some high quality silicone air compressor lube on everything.
  • Removed the chintzy circuit board and replaced it with a 300-amp relay and a 70-100psi pressure switch:

IMG_6946.jpg

  • Tapped out the original outlet port to 1/4" NPT and added a second port, each with a Hi-Flo coupler.
  • Replaced the power wires with 4 AWG wires:

IMG_6948.jpg

IMG_6949.jpg

  • Put an Anderson Connector on it and then wired the other end up behind my bumper on the right front:

IMG_6945.jpg

IMG_6944.jpg

So how did it all turn out? Pretty good! I again aired down one tire to 15psi and aired it up again to 50psi. It took 2:05, which is a 31 second gain over stock! And that was using the hose from my ARB compressor, not one with hi-flo connections on it.

I also tested with the air cleaner caps off to see if that made a difference before I committed to cutting holes in them. It didn't at all. I got the same result, 2:05.

The next thing I'm going to do is build two 2-way hi-flo hoses so I can air up all four tires at once. Maybe put some pressure regulators on them as well so I can just set it and forget it? We'll see.
 
P

Pile of parts

Well-Known Member
Location
South Jordan
Thanks for the info on the upgrades. I'll be interested to hear your report on inflating multiple tires. With the valve stem being the bottleneck, you may not see a huge increase in time - based on the stated cfm of the compressor and modifications for higher flow. I need to go pick up one of these.
 
Stephen

Stephen

Who Dares Wins
Moderator
Location
Never Far From Nowhere
Pile of parts said:
Thanks for the info on the upgrades. I'll be interested to hear your report on inflating multiple tires. With the valve stem being the bottleneck, you may not see a huge increase in time - based on the stated cfm of the compressor and modifications for higher flow. I need to go pick up one of these.
Click to expand...
I don't expect a huge increase in time, but even if I can just air up all four tires in say, 10 minutes, that'd be awesome.
 
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