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ARB high output on board vs VIAIR 400p

sjalkian

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Joined
Jun 2, 2018
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234
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Vienna, VA
This is the kit I run. (linked below) But, I modified it so I can plug my air hose in next to the bumper instead of having to open the hood. It fills up a 35" tire from 10psi to 25psi in roughly 2 min each.

I have no experience with the viair system so I can't speak for it.

I have the same setup, but would love to not have to open the hood. What did you use to move it to the bumper?
 

Alex01

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Mar 23, 2018
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Martinez, CA, USA
I have the same setup, but would love to not have to open the hood. What did you use to move it to the bumper?
I bought a small air hose from the hardware store, a right elbow attachment (for the mount), a new chuck, and made a mount by cutting then bending a piece of scrap metal.
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BoldlyGoing

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Joined
Oct 9, 2017
Messages
536
Location
Atlanta, GA, United States
I own a 400P portable kit, now a backup and used in other vehicles after I installed a Viair 400H hardmount compressor in my jeep.



See: https://wranglertjforum.com/threads/how-to-simple-onboard-air-for-your-tj-lj-viair-400h.10235/

Two thoughts:

1. The 400 series is a very good value when on sale on Amazon. I purchased mine for about $160. Subscribe to an alert on this website and you will be notified when the item reaches your target price:

www.camelcamelcamel.com

2. The Viair 400 series compressors have a 20% greater output than the 450 series compressors, i.e. they are faster. The 400H puts out 2.30 cfm @ 0 psi and 1.75 cfm @ 40 psi whereas the 450 puts out only 1.80 cfm @ 0 psi and 1.39 cfm @ 40 psi. A 400 series compressor has a 33% duty cycle which means that it is rated by Viair to run for 20 minutes at 100 psi at 72*F ambient temperature before being allowed to cool for 40 minutes. This means that a compressor pushing against only 30-35 psi can run longer than 20 minutes although how much longer is not measured by Viair. Since jeepers seldom inflate a tire to more than 30-35 psi and the 400 series compressor can fill a 35" tire from 15 to 30 psi in 2:40 (+/- 5 sec.) and from 0-30 in 5:05 (+/- 15 sec.) this means that one can fill a set of four completely flat 35" tires before the duty cycle becomes a concern or two sets of aired down 35's. In the 6-7 years I've owned a Viair 400 series compressor I have aired up my own 35's and frequently someone else's 33 or 35" tires in the same session and I have never experienced any issues relating to duty cycle or overheating.

Given the choice between the 400 and 450 series compressors I picked the 400 for its 20% greater cfm rating and after using two of them over 6-7 years I still recommend the 400 over the 450.

This is exactly why I went with the 400p Automatic.

I've had it for a year or so and despite topping off my wife's 35's and my 33's, we've never reached its duty cycle limit.

Now, my buddy has the dual piston ARB unit- that thing is a monster and performance wise blows the 400p out of the water, but at more than double the cost, it's definitely not double the value (IMO).
 
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starkey480

starkey480

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Jul 12, 2019
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Chandler, AZ
This is exactly why I went with the 400p Automatic.

I've had it for a year or so and despite topping off my wife's 35's and my 33's, we've never reached its duty cycle limit.

Now, my buddy has the dual piston ARB unit- that thing is a monster and performance wise blows the 400p out of the water, but at more than double the cost, it's definitely not double the value (IMO).
Yeah exactly. At a certain point I’m not willing to pay $300 to save me 4min on filling tires. I’m pretty happy with the 2 minute/tire 15-30 psi rating of the viair.
 
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starkey480

starkey480

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Jul 12, 2019
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Chandler, AZ
For anyone who’s interested the Viair 400P came in today and I did some testing with my 33x12.5” tires. It aired me from 12 to 30 PSI in 2 minutes 30 seconds. Not groundbreaking speeds but honestly 10 minutes of fill time for all the tires isn’t bad. The compressor is much quieter than I thought and is built really nicely. I’m thinking about running a power cable from my battery to my trunk so I don’t have to pop my hood each time. Anyone have any good ideas to do that cleanly?
 

Mr. Bills

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Joined
Nov 24, 2017
Messages
1,892
Location
Area Code 530
You will probably need to run heavy gauge wire or cable to avoid voltage loss due to the relatively long run from battery to trunk.

If you want to eliminate using alligator clips with your portable unit you might consider placing an Anderson connector at the front bumper rather than in the rear so you can have a short wire run. However, I would still raise the hood.

When I installed the Viair 400H in my LJ I thought about whether it was an advantage or disadvantage not to need to raise the hood when airing up at the end of the day.

The maxim "simpler is better" won the day for me, buttressed by the theory that when leaving the trail one really should do a walk around for damage and look under the hood for any issues or low fluid levels before heading down the highway. In addition to being simpler, keeping the compressor switch and hose connector under the hood forced me to raise it which in turn eliminated any excuse for not checking the oil, coolant, etc.
 
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Airjunky

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Joined
Dec 13, 2018
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260
Location
Liberty Lake WA
I have a Slime dual piston pump. Looks like it's only capable of 1.9 cfm. It pumps my 31s up in 2 or 3 minutes. Maybe I'll time it the next time. Cost me about $60.
I see that Smittybuilt has one that is 5.65 cfm. Looks like they're about $135.
 
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starkey480

starkey480

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Jul 12, 2019
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Chandler, AZ
I have a Slime dual piston pump. Looks like it's only capable of 1.9 cfm. It pumps my 31s up in 2 or 3 minutes. Maybe I'll time it the next time. Cost me about $60.
I see that Smittybuilt has one that is 5.65 cfm. Looks like they're about $135.
I can’t speak from experience but I read somewhere Jerry saying the smittybuilt CFM ratings are inflated
 
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TurboTJ

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Jan 5, 2019
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248
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Walnut Creek, CA
I can’t speak from experience but I read somewhere Jerry saying the smittybuilt CFM ratings are inflated
Prior to installing the Viair 400H I was using the Smittybilt 2781 portable compressor. They may inflate their ratings but that compressor is mighty fast, considerably faster than the 400H. I switched to the installed system just because of convenience.
 
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starkey480

starkey480

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Jul 12, 2019
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Chandler, AZ
Prior to installing the Viair 400H I was using the Smittybilt 2781 portable compressor. They may inflate their ratings but that compressor is mighty fast, considerably faster than the 400H. I switched to the installed system just because of convenience.
Awesome sounds like it’s a great option for a low cost portable compressor then. How much faster was it?
 

EzPeezy

TJ Enthusiast
Joined
Dec 23, 2018
Messages
119
Location
San Diego CA, and San Quintin Baja CA
I hard wired the 400p into my jeep after deciding that I didn't need a portable and was only using it with the jeep or the random basketball 😁

I just had to chop off the battery clamps and add terminals. There's already an in-line fuse with the compressor. I bolted the pump onto the rear tire swing under the spare, in a small steel enclosure.