Setting Up Removable On-Board Air - Suggestions and Help

[gundrted+t4r]

I have a '17 TRDORP. I've been looking at On-Board Air (OBA) for some time. I haven't done off-roading and I can't justify spending a ton of money on something I will hardly use.

Last year I ended up with a Viair 450P-RV Automatic Compressor. I bought it for my truck camper after having to use the spare and it wasn't up to pressure. It's a great little compressor. I also setup a regulator that allows me to fill my mountain bike tires while camping. I got a digital air chuck/gun and swapped the the hose with a Topeak bike pump head. I also added a quick disconnect to remove the Topeak and use a standard air chuck.

This got me to thinking about using the same setup in my 4Runner.

Realistically, I would be using this setup for high volume low pressure mountain bike (MTB) tires. Depending on our pressures go between 9 - 19psi (29+ and 27.5/27.5+).

The 450p will fit into the space under the hood in front of the passenger side firewall. I'm a little worried about using it there because I don't want the compressor getting dirty. It is not rated for being exposed to dirt or weather.

This lead me to look at the rear cargo area. All our MTB gear is already back there and so are the bikes. I haven't tested the compressor on the rear 12v outlet. I'm hoping low pressures will equal the lowest power draw for the compressor. The compressor also only needs to run for a few seconds at a time per tire.

I'm thinking of the following configuration.

• AC/DC Power Relay plugged into the rear 110v outlet
• Viair 450p plugged into the rear 12v outlet with the relay controlling the power
• Viair 450p in some type of enclosure (ammo can, plastic bin, ...) and secured in the cargo area
• AC/DC Power Relay is located in the storage enclosure

Using the compressor

• Turning on the 110v plug activates the relay
• The relay allows power to flow to the compressor that is switched on
• MTB tires are filled
• 4Runner is turned off or 110v plug is turned off

I have a sliding rear deck and it looks like I could mount an air fitting to the underside of it. This would allow the air hose/chuck to be attached easily at the rear.

Thoughts on all this ....


Parts List

Enclosed AC/DC Power Relay with Protection & De-Bounce. Screw Terminals. 120V Trigger Input. by DLI
https://www.amazon.com/Enclosed-AC-Protection-Bounce-Terminals/dp/B017743I7S
Price: $12.95

Safe and easy to install. Controls any AC or DC device.
Durable high current relay for long life and reliable switching.
De-bounce circuit for safety. Dry contact relay output - connect to any voltage circuit.
Thermal switch and circuit breaker add safety, limiting current to 15 Amps.
Includes detachable power cord.

Viair 450P-RV Automatic Compressor
450P-RV Auto Portable Compressor | VIAIR
PERFORMANCE DATA

PSI CFM A BAR LPM A
0 1.80 12 0 51.0 12
10 1.75 14 1.0 47.6 15
20 1.60 16 2.0 43.3 17
30 1.52 17 3.0 38.2 18
40 1.39 18 4.0 34.0 19

SPECIFICATIONS
-12-Volt
-Permanent Magnetic Motor
-Duty Cycle: 100% @ 100 PSI
-Max. Working Pressure: 150 PSI
-Max. Amp Draw: 23 Amps
-Ingress Protection Rating: IP54
-Dimensions: 10.87in L x 5.8in W x 7.48in H
-Net Weight: 13.05 lbs.
-Power Cord Length: 8 ft.
-Primary Air Hose Length: 30 ft.
-Extension Air Hose Length: 30 ft.

ARO R37121-600-VS Air Regulator 1/4" NPT, w/ Gauge - 250 psi Max Inlet
https://www.amazon.com/gp/product/B0057D8LMY/ref=oh_aui_search_asin_title?ie=UTF8&psc=1

TORQIFY AT875 Tire Inflator Air Tool with Digital Pressure Gauge
https://www.amazon.com/gp/product/B071CF514F/ref=oh_aui_search_asin_title?ie=UTF8&psc=1

Topeak SmartHead Bicycle Floor Pump Upgrade Kit
https://www.amazon.com/gp/product/B000FIE4JK/ref=oh_aui_search_asin_title?ie=UTF8&psc=1

Photo of setup in my truck camper while in Fruita, CO

 

[Jimmyasheville]

Seems like a lot of time trouble and money to pump up your mtb tires. How bout some pics if your bikes, in action maybe. And a pic of how you fit them in a 4 Runner! Thanks

 

[gundrted+t4r]

Seems like a lot of time trouble and money to pump up your mtb tires. How bout some pics if your bikes, in action maybe. And a pic of how you fit them in a 4 Runner! Thanks

Hahaha ... no kidding right ... I've been filling the tires at home with my garage compressor. I still throw my old Topeak in the back just in case. It is overkill, but it would be cool.

Maybe a fridge with cold beers or a margarita maker would be cooler

 

[GearJunkie88]

I agree that this is a whole lot of work and expense to pump up a bike tire. A bit of a Rube Goldberg Machine for such a simple task. I have used a floor pump forever... the only time a compressor is needed is when seating the bead on a fresh tubeless setup on occasion... which you’d do in your garage, not from the back of your car at the trailhead. Typically, the tire isn’t completely flat, so you really only need about 3 pushes on the floor pump.

 

[Jimmyasheville]

Do you think that setup would inflate a blow up paddle board? Now that’s one freakin hand pump I don’t want to mess with.

 

[tigger]

I did a Viair 400P under the hood with no issues. Pretty easy install.
Viair Install

 

[BP22]

I did a Viair 400P under the hood with no issues. Pretty easy install.
Viair Install

Great job! This is exactly what I was looking for. Thank you.

 

[gundrted+t4r]

Do you think that setup would inflate a blow up paddle board? Now that’s one freakin hand pump I don’t want to mess with.

If you get a constant duty model like the 450P, yes it should inflate anything you hook it to. The question is how long it would take. Also, for something like a large like a tire or paddle board, you would want the compress connected directly to the battery and the engine running.

 

[gundrted+t4r]

I did a Viair 400P under the hood with no issues. Pretty easy install.
Viair Install

Thats a nice install. i didn't think to mount it on the fender. Have you had any issues with dirt on the compressor?

 

[tigger]

Thats a nice install. i didn't think to mount it on the fender. Have you had any issues with dirt on the compressor?

It would get dusty, but turn it on, and blow it off. As long as you don't go through seriously deep water, you shouldn't have an issue. Just change out the filter when needed.

 

[gundrted+t4r]

It would get dusty, but turn it on, and blow it off. As long as you don't go through seriously deep water, you shouldn't have an issue. Just change out the filter when needed.

Good to know. The last thing I wanted to do is kill the little guy and have to buy a new one.

I agree that this is a whole lot of work and expense to pump up a bike tire. A bit of a Rube Goldberg Machine for such a simple task. I have used a floor pump forever... the only time a compressor is needed is when seating the bead on a fresh tubeless setup on occasion... which you’d do in your garage, not from the back of your car at the trailhead. Typically, the tire isn’t completely flat, so you really only need about 3 pushes on the floor pump.

Yes, this is complex. I already have the compressor for my truck camper.
I would like to put the pump the good use and not have it collecting dust. The flip side is, I've already the bike tire inflation setup done [regular, air gun and chuck]. That's half the battle.

In a perfect world, I would like 'sled' [as my engineering friends call it] that I could drop into my 4Runner or Camper. Maybe even include a .5gal tank at some point.

 

[jhguth]

Quote:
SPECIFICATIONS
-12-Volt
-Permanent Magnetic Motor
-Duty Cycle: 100% @ 100 PSI
-Max. Working Pressure: 150 PSI
-Max. Amp Draw: 23 Amps
-Ingress Protection Rating: IP54
-Dimensions: 10.87in L x 5.8in W x 7.48in H
-Net Weight: 13.05 lbs.
-Power Cord Length: 8 ft.
-Primary Air Hose Length: 30 ft.
-Extension Air Hose Length: 30 ft.

you won't be able to run that off of the rear 12v outlet, you'll blow the fuse.

you'll need to run at least 10-ga wires to the back from the battery to power it, you can add a relay under the hood and switch in the cab if you want switched power

(i assume the ac relay was so you didn't have to run wires and switch for a dc relay?)

 

[gundrted+t4r]

you won't be able to run that off of the rear 12v outlet, you'll blow the fuse.

you'll need to run at least 10-ga wires to the back from the battery to power it, you can add a relay under the hood and switch in the cab if you want switched power

(i assume the ac relay was so you didn't have to run wires and switch for a dc relay?)

You are correct, however you are looking at the max draw. The max draw occurs at/near the max psi and lower cfm through-put. There is no expectation around filling car/truck tires with the rear 12v plug.

10ga wire would be complete overkill for something like this. 8ga would be just a waste of wire. The attached power cable doesn't have an XXga printed on it. Its a little larger than my Battery Tender cables (18ga). I would put the OEM cable at 14ga or maybe 12ga.

A high volume mountain bike tire basically allows the pump to run at its highest cfm and lowest resistance. The pump runs for about 5-15 seconds at between 5psi and 15psi. The table below outlines the manufacture specs around pressure, cfm and amp rating.

PERFORMANCE DATA
PSI CFM A
0 1.80 12
10 1.75 14
20 1.60 16
30 1.52 17
40 1.39 18
50 1.27 19
60 1.18 19
70 1.09 20
80 1.04 20
90 0.97 21
100 0.94 22
110 0.90 23
120 0.86 23
130 0.81 22
140 0.76 21
150 0.72 20

 

[jhguth]

its more than double the outlet's rating at max, every amperage on your chart exceeds the 120W rating. you'll blow a fuse.

and yes if you run that to the back a 30' run for 25A means 10awg. the oem cable is short, it doesn't need to be more than 12 awg. you could step down to 12awg if you keep your wiring direct and ground in the rear.

 

[gundrted+t4r]

Hmm .... I didn't realize the output was that low on the rear socket.

 

[jkaylen]

I have an ARB compressor in my engine bay and installed an electronic valve to shunt air to this rear chuck when I activate the compressor with the switch displayed versus the switch on my dash (that one only turns on the air compressor). I use it for SUP and Mountain Bike Tires. Too low flow/high pressure for the ducky.

 

[Blubayou]

I did a Viair 400P under the hood with no issues. Pretty easy install.
Viair Install

I have the same compressor and have been considering a more permanent mount under hood (currently I just keep it in the bag in the trunk, but am tiring of moving it around). Thanks for sharing that post. I did cut off the alligator battery cable clamps on mine and replace with an Andersen connector to make quicker, more reliable connections but I still have to dig it out of the bag each time I use it.

One question, do you find you look at the gauge much? Kinda wondering what purpose it serves under the hood if you are at a tire filling (where you can’t see it).

 

[tigger]

I have the same compressor and have been considering a more permanent mount under hood (currently I just keep it in the bag in the trunk, but am tiring of moving it around). Thanks for sharing that post. I did cut off the alligator battery cable clamps on mine and replace with an Andersen connector to make quicker, more reliable connections but I still have to dig it out of the bag each time I use it.

One question, do you find you look at the gauge much? Kinda wondering what purpose it serves under the hood if you are at a tire filling (where you can’t see it).

No, it is more for keeping an eye on the pressure switch occasionally to make sure it stays within range.

 

[gundrted+t4r]

I have an ARB compressor in my engine bay and installed an electronic valve to shunt air to this rear chuck when I activate the compressor with the switch displayed versus the switch on my dash (that one only turns on the air compressor). I use it for SUP and Mountain Bike Tires. Too low flow/high pressure for the ducky.

I really like the cleanliness of the panel. Was it difficult to run the wiring and air line from the engine compartment to the rear wheel well?