just curious ... Viar thoughts.

[Shane]

viair 380's are rated to 200 psi @ 100% duty cycle and the dual packs come with 165 psi ON / 200 psi OFF pressure switches ... not too bad fill times up to 150 psi BUT it take forever for them to build pressure from 150-200 psi,

ok, with that out of the way ... why not run a 120 psi ON / 150 psi OFF pressure switch? the compressors seem to fill to 150 psi fairly quickly and these systems don't need 200 psi anyway. seems to me it would be a lot less work on the compressors and the fill time for a 150 psi is less.

what am I missing?

thoughts?

[LONGHAIR]

I don't know Shane? Maybe because the higher pressure translates into more volume at the lower "regulated" pressure? So, if you cut it down with a lower pressure switch, it would run more often. As you said it run be for less time each cycle and with 100% duty cycle it really wouldn't matter...

Maybe it works out to be about the same? I suppose it would depend upon the volume used?

[texastrendz]

vehicle weight and bag sizes, relative to first lift off of the ground.

[Shane]

Originally Posted by LONGHAIR

I don't know Shane? Maybe because the higher pressure translates into more volume at the lower "regulated" pressure? So, if you cut it down with a lower pressure switch, it would run more often. As you said it run be for less time each cycle and with 100% duty cycle it really wouldn't matter...

Maybe it works out to be about the same? I suppose it would depend upon the volume used?

That's what I was thinking LONG ... I guess what I'm trying to justify to myself is: Would I rather have the compressors cycle more often, but for a shorter duration each cycle or have them cycle less often, but for a longer duration each cycle.

I don't play with the bags (or "clown" as N2TRUX says ) as much as some, so I'm trying to figure out the advantages of one over the other. One advantage (my opinion) would be the slower fill times with less pressure ... it's really difficult to "fine tune" ride height @ 200 psi with 3/8" valves and 3/8" air line.

Hindsight being 20-20, I wish I had gone with 1/4 valves.

[Shane]

Originally Posted by texastrendz

vehicle weight and bag sizes, relative to first lift off of the ground.

[texastrendz]

I was thinking with a lower pressure setting that you would have a hard time lifting a truck with high volume bags and a larger size line. I guess it really comes down to volume of the tank also. With the truck "layed out" it is going to consume some air on the first lift. I know pressure and volume ar all relative, I guess speed and storage are going to be a balancing act on the compressor cycling. I did purchase an adjustable pressure switch for mine at the local suspension shop in houston. It uses an 1/16 allen wrench to adjust the cut off pressure for some fine tuning. This way you can dial it in where you want it. I left it where it was set 165 psi and have not messed with it yet. Good luck with it and let us know what you find out.

[Shane]

Good points ... I wasn't even figuring in initial lift from an entirely empty system. I was more concerned with the fill times between the on and off pressures.

I've got a 120 - 150 psi switch on order. Gonna experiment with it.

[PBFAB.COM]

Originally Posted by Shane

Good points ... I wasn't even figuring in initial lift from an entirely empty system. I was more concerned with the fill times between the on and off pressures.

I've got a 120 - 150 psi switch on order. Gonna experiment with it.

I too would think that 200 is overkill on most applications. Seems to me somewhere between 150 and 175 would be the sweet spot.

Let us know how your mad scientist experimentation goes.

[BB72CHEVKT]

How about posting a pic of your truck Shane? I do not recall ever seeing it posted.

[edflores]

They sell a 145on-175 off switch. I liked using that one on my 480.

[N2TRUX]

Shane one problem I see with more frequent run cycles is the noise. My compressor is mounted at the very rear of the truck and I still think its too loud. I am planning to go with two compressors to reduce the cycle time so I don't have to hear the thing run.

[texastrendz]

I think his intentions are to run dual compressors from his first statement. Dual compressors are the norm now with guys that have knowledge of air suspension system. lol

[Shane]

Originally Posted by N2TRUX

Shane one problem I see with more frequent run cycles is the noise. My compressor is mounted at the very rear of the truck and I still think its too loud. I am planning to go with two compressors to reduce the cycle time so I don't have to hear the thing run.

I'm already running dual 380's and my question is for the same reason you list. Noise. Well, not just noise as much as vibration/resonance. Mine are also mounted at rear ... one on each side of the frame. My cab is insulated with FatMat AND the foil jute and it's still more than I want to listen to. You feel it as much as you hear it.

I have partial hearing loss in my left ear and/or I'm getting old and turning into my Grandpa cause I can't stand loud crap anymore. I guess what I'm trying to figure out for my own sake/sanity is would I rather listen to it more frequently but for less time or less often for a longer period of time.

Hope that makes sense.

[Shane]

p.s. If they weren't so dog-gone ugly, and I had room, I would run an engine-driven compressor.

[texastrendz]

http://oasismfg.thomasnet.com/item/a...ors/item-1052?

Always an option, if you can afford it!

[dv8customs]

The 380's tend to be loud. The larger 480's are much quiter.

The main reason for 200 psi is the initial lift as stated. If you are only running 150 then when you first lift it up you likely won't make it to ride height up front and then you have to sit and wait for the tanks to fill again. That is more annoying to me than noise.

[Shane]

Originally Posted by dv8customs

The main reason for 200 psi is the initial lift as stated. If you are only running 150 then when you first lift it up you likely won't make it to ride height up front and then you have to sit and wait for the tanks to fill again. That is more annoying to me than noise.

who runs more than 150 psi in their front bags?

[jimmydean]

Originally Posted by Shane

who runs more than 150 psi in their front bags?

150 in the tank, not the bag. A 5 gallon tank with only 150psi might not have enough volume to fill 4 bags to ride height.

Thats how I took it, anyway.

[Shane]

oh ... ok ... I misunderstood.

[SCOTI]

Originally Posted by jimmydean

150 in the tank, not the bag. A 5 gallon tank with only 150psi might not have enough volume to fill 4 bags to ride height.

Thats how I took it, anyway.

x2.

Front set-ups for these trucks prob use 70-80psi avg & rears are 40-50psi min. Just the fronts alone could bleed a tank under the pressure point of the 150psi switch from full drop to ride height. Right?

[Shane]

two 3 gallon tanks pressurized to 150 psi have enough volume to raise the dead-empty bags to ride height on a single fill before the compressors kick on.

the same result as with the 200psi switch ... one fill and the compressors kick on.

same pressure loss (150-120) or (200-165) ... the only difference is the compressors run less to get back to the 150 psi from 120 psi than they do to get back to 200 psi from 165 psi. the higher the pressures the less efficient the compressors are.

does that make sense?

[N2TRUX]

Originally Posted by Shane

I'm already running dual 380's and my question is for the same reason you list. Noise. Well, not just noise as much as vibration/resonance. Mine are also mounted at rear ... one on each side of the frame. My cab is insulated with FatMat AND the foil jute and it's still more than I want to listen to. You feel it as much as you hear it.

I have partial hearing loss in my left ear and/or I'm getting old and turning into my Grandpa cause I can't stand loud crap anymore. I guess what I'm trying to figure out for my own sake/sanity is would I rather listen to it more frequently but for less time or less often for a longer period of time.

Hope that makes sense.

Ok, we are on the same page. Exact same reason I plan to go to dual compressors myself.

[Shane]

what?

[N2TRUX]

Exactly...

[dropnstylez]

ok first off the 380s are loud plain and simple. buddy had the 380s and i bought the 444's and 2 days later buddy swapped to the 444's as well. i had mine at 200 psi with half inch valves up front and 3/8s in the back of my ranger with half inch line all the way around (hey i was coming from hydraulics and thought i wanted fast). i had to buy slow downs for the rear dumps and fills. with 200 psi it was just stupid to try to control (and i had shocks). So that is one thing to think about the psi will speed up your system, second most compressors even if they go to 200 psi become less efficent the higher the psi and also draw more amps usually right after 150 (that i dont know why). Dual compressors are the way to go for sure but like i said the 380s are just loud, make sure the rubber feet are still good. All that being said i just ordered an accuair setup with the dual 400s and they are only 150psi but fill time on 5 gal tank with 2 is only 54 sec. I prefer the lower pressure quick cycling. im always afraid here in az with the heat that the long run times would burn up a compresor ( i did burn one of the 444's up but was under warranty, internal short).