Subaru Forester Onboard Air Compressor with DIY 4-Way Inflator

[@bruceyyyyy]

I have this same pump (or a Chinese knock off equivalent) and it is beastly. We had it in CO, not sure if you saw it. We aired up JonDZ's Honda with it. Good stuff though! Couple extra thoughts: 1) This pump WON'T set a bead. On a 245/65/17. It almost will on its own. But it won't. It will hit thermal shut off for the duty cycle first. Ask me how I know this. A small tank added could possible have enough volume and pressure to set a bead if it comes to it. But not sure where you could hide it. Especially in the engine bay. Possibly where a dual exhaust set up could go? 2) I didn't see the ends of the hose you made but if they're the screw on schrader valve connections they make quick disconnects for them. They work similar to the air chucks. Put on, slide the collar, connected. They're cheap too. I want to say $10. Could be even quicker if you don't have them! 3) Let me know how the pump holds up in under hood heat. I've never had good luck with them there. Even when they're 'rated for engine bay use' 4) Rivnuts! If you don't want to tap relatively thin sheet metal. Rivnuts are a great way for making threaded nuts in a surface you can only access one side of. They're relatively cheap (and arguably cheaper than a tap and die) Keep at it Matty!

[@MatthewHeiskell]

Thanks Bruce! Yeah, resetting a bead usually takes a shop sized air compressor, or some flammable spray used in conjunction with a normal air compressor. I’d just switch to my identical 5th before messing with any of that stuff though. I’m a big fan of rivet-nuts, but there’s plenty of steel to cut those threads. The compressor is 18 pounds, shared among just 3 points, each one has to hold only 6 pounds, super easy. On mine I made a custom aluminum bracket to mount the 4th corner too. Definitely secure, even without that! The cover keeps the compressor clean and dry. It has a duty cycle of 15 min on, then 5 off, but it airs all 4 tires up from 15psi to 32psi in 2 minutes, so I don’t think that heat will be an issue. Yeah, the 4-way uses the quick clip on chucks. Normally a single Schrader valve is the bottleneck, but filling into 4 of them at the same time solves that flow restriction. It’s a great setup. We aired up and down 4 cycles while we were in Moab recently. Couldn’t be happier with the setup! I just hope the Outback and Crosstrek people can find a place to mount one too.

[@salcigar]

I've been waiting for a video like. You're the first I've seen to hard mount the Napa compressor. Nice job.

[@MatthewHeiskell]

Thanks! It's a beast of a compressor, especially for the price. Still can't believe that it fits so nicely!

[@pf465]

Looks great. I had been eyeballing that spot for my OBA compressor system build, but decided against mounting it there due to under hood temps during the summer months here in California. I'm using the spare tire well to house two tanks I harvested off an old hand me down compressor that stopped working, and since the 5th spare does not fit in there anyway, it's the perfect utility for that space. I wish I had the knack for filming my projects like you do, as we have almost parallel forester ideas with slight differences (which can be beneficial to the community).

[@MatthewHeiskell]

Right on! There's a ton of useful space under there! Honestly, if you have an air compressor, tire patch kit, glue tread kit (look it up) and emergency tire valves (look those up too), and a can of fix-a-flat, then I think you can live without a spare tire. And all that stuff will be helpful to other people too. Just film on your phone, haha. That's what I do most of the time.

[@captain3491]

This is a pretty cool little project. Looking at the prices for all your links, the entire build looks to be around $400. Not bad, really!

[@MatthewHeiskell]

Yeah, not bad. And a lot of those things will be useful later, like the tap and die set and crimping tool.

[@asherabiel]

Looking forward to more videos from you. I also have a Forester Wilderness. You influenced me to install an onboard air compressor. I love how detailed you are in your instructions. Keep the mod videos coming.

[@MatthewHeiskell]

Fantastic! Nice vehicle choice! You’ll love the onboard air and 4-way! Let me know if you have any questions! Easiest way to message me is on IG. I’m sk_foz

[@Keillan5480]

Do I need this? No. Do I want this? Absolutely. I already have a voswitch installed that I believe I could wire it into. I have a compressor in my car anyway as a “just in case”. Would be nice to have this setup to save some room.

[@MatthewHeiskell]

It’s a sweet setup! Airing up and down is quick and easy!

[@CM-ef8fu]

Man that is so sick! Any guesses if that works for a 2012 Forester too? Thanks!

[@MatthewHeiskell]

It should work on a 2012 Forester. You just need some vertical space in that area. Pop the hood and take a look.

[@Ferretts89]

Well done good sirs!

[@MatthewHeiskell]

Many thanks! 😄 Fitting such a powerful air compressor into the engine bay is a big win for all 2019+ Foresters!

[@ohimalbert]

How's the setup holding up so far? I'm going to try with 3 bolts 😅

[@MatthewHeiskell]

He’s reported zero issues, go for it!

[@ohimalbert]

Install went well!Thanks for creating this tutorial and trail blazing these things for the Forester community! Hope to see an Imogene pt2 with the wilderness.

[@MatthewHeiskell]

Awesome! 😄 Such a slick setup, right? We had plans to hit Colorado this weekend, but Imogene pass is still closed because of the snow. Wife and I are going to hit it 4th of July weekend. I’ll have her drive it so I can fly the drone. So be pretty epic and I can’t wait to test the FW’s better gearing. Cheers man!

[@willba4]

clamping the negative on that side of the sensor, bypasses the current shunt. it can confuse the car regarding the state of charge of the battery, which can lead to the alternator doing weird shit as it thinks the battery is full when its empty, or empty when its full. (i've experienced this on other cars....) otherwise, super nice and neat install!

[@MatthewHeiskell]

Hey William! Yeah, for research purposes, on the new Forester, I installed some stuff on that other terminal. Like you said, it allows the car to detect the amount of current being used, but the 15 amps used for the voltage booster (fast charging the EcoFlow power station) was apparently too much. The car kept interrupting it, turning it off then briefly on over and over, very frustrating. This would have been really very frustrating if I was trying to run a winch and do a recovery. Using the other terminal is a MUST for other high power things like a winch. I was hoping that by using the other terminal I could let the car detect how much current I was using, but I can say for sure that 15 amps is too much. However, the car is still able to detect overall voltage, which is enough for the alternator to do its job. Bottom line, use the other terminal for high draw applications.

[@kevinm5177]

Looks awesome. Does the compressor care about its orientation as far as oiling goes? Also, can you reach up inside the fender and add a nut to the rubber mounts? Fun project!

[@MatthewHeiskell]

The air compressor does not care about its mounting orientation. You could add nuts to the lower ends of the rubber isolators, but that's not necessary because all the holes are tapped (threads cut with a tap)

[@TheEdudo]

"airs down" isn't that to deflate?

[@MatthewHeiskell]

Yup! Same thing, but that's the terminology that most off roaders use.