22 PSI Too Much??
05-05-2009, 11:19 PM
#1
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22 PSI Too Much??
Just completed the DSV, Big Line Kit and Holley Blue install. I had about 12 PSI at idle so I bought a Moroso spring and stretched a tiny bit. Now I have 22 PSI and 20 PSI WOT. 
Is that too much? None of the metric/JIC fittings leaked nor did the Holley. My only worry is the new VP-44 diaphram and/or the stock filter canister seals. Should I compress the spring or just enjoy my new VP and Vulcan/Holley set up?
It was cool to dump the throttle and the pressure gauge barely move!
Thanks,
Tom
Is that too much? None of the metric/JIC fittings leaked nor did the Holley. My only worry is the new VP-44 diaphram and/or the stock filter canister seals. Should I compress the spring or just enjoy my new VP and Vulcan/Holley set up?It was cool to dump the throttle and the pressure gauge barely move!
Thanks,
Tom
05-06-2009, 06:59 AM
#4
Did you ask an injection pump service center?
Pressurizing a liquid heats it up. Do you want to add heat to the fuel---no.
The pump guys have told me anything more than 12-14 is too much.
Yes there are some with 20-25 and are running fine, but it isn't optimal.
Pressurizing a liquid heats it up. Do you want to add heat to the fuel---no.
The pump guys have told me anything more than 12-14 is too much.
Yes there are some with 20-25 and are running fine, but it isn't optimal.
05-06-2009, 07:37 AM
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As a matter of fact, YES.
According to Bosch, where we get our injector pumps from, as long as we didn't exceed the 50 psi that the fuel lines and filter canister are rated for it was actually optimal to use higher pressures.
As far as heat goes, you are not dead heading the lift pump, (which would cause heat) as the fuel is being recirculated through the overflow valve, and the return line, back to the tank.
According to Bosch, where we get our injector pumps from, as long as we didn't exceed the 50 psi that the fuel lines and filter canister are rated for it was actually optimal to use higher pressures.
As far as heat goes, you are not dead heading the lift pump, (which would cause heat) as the fuel is being recirculated through the overflow valve, and the return line, back to the tank.
05-06-2009, 10:07 AM
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O.k....now I am puzzeled.
I had 20-22 PSI driving in to work this morning until about 2 miles out.....looked at my gauge and bam 12PSI
Perhaps the spring compressed? The Moroso spring was shorter and stiffer than the Holley? Could the spring have compressed already?
Tom
I had 20-22 PSI driving in to work this morning until about 2 miles out.....looked at my gauge and bam 12PSI
Perhaps the spring compressed? The Moroso spring was shorter and stiffer than the Holley? Could the spring have compressed already?
Tom
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05-06-2009, 10:32 AM
#8
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For a while I was running 25 or more psi. Probably ok for the VP but your seals in the filter housing (fuel heater & water-in-fuel) may begin to leak over time due to the higher psi as in my case. Install the regulator that came w/the holley blue and you should be ok. Set so WOT is >12 psi or so. Another thing is that you may exp hard start issues due to the higher psi.
05-06-2009, 01:17 PM
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O.k....now I am puzzeled.
I had 20-22 PSI driving in to work this morning until about 2 miles out.....looked at my gauge and bam 12PSI
Perhaps the spring compressed? The Moroso spring was shorter and stiffer than the Holley? Could the spring have compressed already?
Tom
I had 20-22 PSI driving in to work this morning until about 2 miles out.....looked at my gauge and bam 12PSI
Perhaps the spring compressed? The Moroso spring was shorter and stiffer than the Holley? Could the spring have compressed already?
Tom
I was running a holley pump also.
05-06-2009, 09:01 PM
#10
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Don't install the regulator.
I ran the Holley for 3 years @ 21 psi (as you can see in the pic) until it failed and left me on the side of the road. Now i have the AD100 and run 17psi.
I ran the Holley for 3 years @ 21 psi (as you can see in the pic) until it failed and left me on the side of the road. Now i have the AD100 and run 17psi.
05-06-2009, 11:25 PM
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I agree with dglass, My FASS puts me at 21 idle and about 15-16 WOT while empty. Barely lower while towin. I seem to hear/read much more about holly pump problems then FASS and Air Dog combined. Just my .02.
But hey dont mean to diss anyones set up, if yours is runnin good then kick as!
But hey dont mean to diss anyones set up, if yours is runnin good then kick as!
05-07-2009, 06:27 AM
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I have been running around 20 psi on my FASS HPFP for a while. I totally detuned the truck a year or more ago and want to go to a lower pressure pump with less flow. Optimal fuel temperature is 100 degrees or lower. Once you get up above that you really start losing BTU. The injection pump is going to be running at engine temp so now you are returnng too much hot unused fuel back to the tank with the higher flow pumps, heating the tank fuel up. These trucks have no fuel cooler so you rely on the tank to do the cooling. I don't want to be running hot fuel all the time.
05-07-2009, 07:38 AM
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Anything above 12-15 is just causing wear. There was a really good article in the TDR magazine abouy just this issue a few years ago. This number came straight from Bosch. They said above this is actually harmful for the pump..... I know a ton of guys who have pressures in excess of this and are fine but the truth is not only Bosch says it is too much but also the Bosch shop I used to do business with.
There is no HP gain from higher pressures on the VP trucks (I have done a ton of dyon runs with different pressures. In fact as long as you have head pressure the HP level is constant. Cooling of the VP is paramount and the fuel does this, hence the reason for the 12-15 psi.
There is no HP gain from higher pressures on the VP trucks (I have done a ton of dyon runs with different pressures. In fact as long as you have head pressure the HP level is constant. Cooling of the VP is paramount and the fuel does this, hence the reason for the 12-15 psi.
05-07-2009, 07:52 AM
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I've been runnin a 22 psi spring in my Airdog since I installed it almost 5 years ago. I have over 100,000 miles with this set-up including a large drawstraw in the tank and all of the fittings and lines replaced with -10 stuff. The truck is driven with the TST left on at all times and is still on the same VP. It could go out tomorrow but it has lasted longer than what most people see. Especially seeing as how the box is left on all the time. It's wired through the ecm controls so I see no hardstart issues what so ever. I think factory Engineers opinions on what is a necessary fuel psi become somewhat irelevant once you start hitting hp areas well above the stock ratings they are familiar with.