JKOwners Forum banner

Viair 400H ( 400C) torture test - Small compressor > Big results

22K views 102 replies 27 participants last post by  maverick 
#1 ·
Anybody who read my thread about the speed of the 400H and 400C compressors knows that I had a little torture testing that I've been wanting to do. Finally had some warmer weather today and I've completed the torture test.

Some back story, and why am I doing this? The 400H and 400C are the same compressor, other than the fact that the 400H has an integrated on off switch. These two compressors are very interesting for two reasons. First off they are among the fastest compressors that Viair offers, putting up to 2.56 CFM. The are also among the lease expensive compressors that Viair offers. Their size makes them a natural to install in the JK engine compartment.

Viair Compressor Speed Comparison Data:

For the price and size the 400C and 400H stand out as the speed leaders, in a big way.

The big question for these compressors is duty cylce. Rated at 33% duty cycle at 100 PSI, how would they do filling tires?

My first test was filling 8 tires, connected through an air manifold to 4 tires at a time. The first set of tires were 37's on 17" rims and they were followed by 35's on 15"rims. The fill time for all eight tires was 50 minutes. So with no more than a very short break the compressor did not overheat with a 50 minute run time. Of course, I wanted to know more so... I decided to torture this little compressor and here's what I did.

My goal was to see how long the compressor would run. These compressors are are equiped with thermo-protection and automatically shut down when they get too hot. I gathered up a 20 gallon air tank, 50 foot air hose, a high quality liquid filled Wika pressure gauge, infrared thermometer and a stop watch (later on, I had to find a 5 gallon water bucket - more on that later). I installed the pressure gauge on the air tank hooked one end of the air hose to the compressor and the other end to the air tank. I turned the compressor on and let it run, until the tank reached 30 PSI. I then opened the air tank drain valve and adjusted it, to where the pressure even. I didn't have a way to keep the pressure at a prefect 30 PSI, but it never dropped below 26 psi and never went above 34 PSI. Now these things get hot. REALLY HOT. After the compressor ran for a few minutes, I noticed that the air hose wasn't looking very good. The air coming out of the compressor was heating it and it looked like it was going to fail so I gathered up 5 gallon bucket of water. I emersed the quick connect fitting and a couple feet of hose to keep the air hose cool. This wouldn't effect the testing of the compressor in any way. Every ten minutes, from the 50 minute mark on, I checked the temp of the compressor head and outside cylindar wall.

Here is the data:



Here's the graph:


Results and Conclusion:

After the compressor filled the 20 Gallon tank, it ran for 2 hours 32 minutes, then shut down. After about 20 minutes if fired back up again.

On the tire fill testing the compressor filled four 37" tires from 9 PSI to 27 PSI in 16 minutes.

What have we learned from all this? First of all, we know that this is only a 33% duty cycle compressor. But two and a half hours at 30 PSI, that's friggin great. For filling tires, the 400C and 400H represent what I believe is by far the best value for compressor based onboard air systems.

:smokin:

5/16 update: Torture test part duex.

This one was a different and done for the guys who have been concerned about how the 400 series compressors will run after being in a hot engine compartment. For this test I really turned up the heat. Here's the test.

After a 2 hour drive from the desert.

I set out to repeat the following steps over and over again until the thermal protection kicked in on the compressor. Fill the 2 gallon tank to 145 PSI, drain the tank to zero and repeat. I figure this is the compressor running at an average of about 110 PSI, which should really kick it's butt. I defined success for this test if it would run continuously for 20 minutes in this manner. This given I was pleasantly surprised that it ran for a total of 54 minutes. Again, the 400 series compressor kicked ass. This is the same 400H that I've used for all of my testing.

As far as tires fills are concerned, I did gather one piece of data today. If I fill the tank to 145 PSI and turn the compressor off, the tank will fill one tire from 9 PSI to 18 PSI.
 
See less See more
3
#3 ·
Yup :grinpimp:

The guys from Two Track Minds have started a new company (Sinister Fab Works) and they will be selling them.

They should be shipping next week.

:smokin:
 
#26 ·
For the most part that is current. The position of the tank is 100% correct in those pics. The brackets are a little stronger and I have custom made u-bolts the allow for max clearance.

Thanks for posting the link. :smokin:
 
#32 ·
I didn't realize that you'd be reading this. Here's a revised graph that will be easier to understand:


Warning: this chart does not account for the likely hood of touching a hot compressor after a given number of beers.
 
#35 ·
Always a concern. This isn't anything new though. Guys have been running these compressors in the engine compartment for over a year. I was just interested in seeing how far I could push it.

You reference Two Track Minds (Sinister Fab Works), but have Dominion Offroad brackets on your site. Are they the same?
I am working together with Sinister. If you're a JKO member then buy the compressor bracket from them. I'll have Jason post up with details asap.
 
#37 ·
I like the idea of having one of these as a backup to a co2 system. Good to know they will run forever!
 
#40 ·
After the compressor filled the 20 Gallon tank, it ran for 2 hours 32 minutes, then shut down. After about 20 minutes if fired back up again.

On the tire fill testing the compressor filled four 37" tires from 9 PSI to 27 PSI in 16 minutes.

What have we learned from all this? First of all, we know that this is only a 33% duty cycle compressor. But two and a half hours at 30 PSI, that's friggin great. For filling tires, the 400C and 400H represent what I believe is by far the best value for compressor based onboard air systems.

:smokin:
I'd love to see a side by side comparison.with ARB. And even more, would've loved to have seen this before I bought the ARB setup. There's no way the ARB runs as hard as what you're showing with the Viair. So for it's shut down twice now while I've been airing up. I wouldn't have minded it so much, but I was real thirsty both times. :beer:
 
#52 ·
That's good question. I purchased a compressor from Viair and they sent this to me. I noticed that the head design was different and put a call into them. I was describing what I had and they finally determined that the factory had accidentally put the wrong head on this 400c. They also told me that if there was one, that there may be a pallet of them in the warehouse. This head is a patented head that is used on the heavy duty IG (Industrial Grade) series of compressors. This head provides better cooling than the standard head. So I had them check the warehouse and sure enough they had a pallet of them. I only have 15 of them left, but these are what I'm shipping for anybody who purchases from stock that I have on hand.
 
#63 ·
I've already got the lowest prices on the compressor and the tank. Unlike other dealers, I'm testing the hell out of this stuff and designing custom systems. There's only so much I can do.

Eventually, I'll have some bundles that will save a little more dough, but for now, the prices aren't getting any better.

:smokin:
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top