Competition Here's a crazy one for you.

[Marco]

I think someone might find this one usefull...

A little background first.



This summer my lift and pusher pumps died a slow death. They ended up with 0 Psi @ idle. Back then the FASS was on backorder, then the time to ship it... I had to do something in order to keep my truck on the road till the FASS would have arrived.



The only fuel pump I had handy would deliver a pressure of 30 Psi.

( That's what the MFR declared. )



What the heck, I use this one for a while!



Once everything was installed I discovered that this pump would run 55 Psi @ idle... . Oh well it was installed, I figured I could take it for a spin anyway.

(I found out later that the FP under WOT would stay arround 35Psi. )



Hello! There was a very noticeable performance gain mainly form the mid to high RPM range.



I've driven the truck for about 1K miles with this "lift pump" till the FASS arrived. I have noticed no ill side effects during that time!



You know with all the hype about too high or too low fuel pressure to the VP I didn't feel comfortable and in the FASS went.



Now to the point.

For you guys with "extreme" trucks. What about such a pump in parallel to the normal fuel pump(s)? You'd need only a couple of check valves in order to hook up the two systems together... At the track / Dyno whatever... with the flip of a switch...



Thought's?



Marco

 

[snowracer69]

get a system that can push 15 psi no matter how much fuel you need and run it. If for you that's a FASS, then so be it. I prefer mechanical as there are a lot fewer things to go wrong, so I went with the RASP.



I know that with just the change of a single spring I can go from 15 psi to 25 psi and higher... and I believe one pickup had the system pushing 60 psi at one time. The VP-44 can only use/deliver so much fuel, no need to give it more than that.

 

[Marco]

snowracer69,



What kind of LP you like, I don't care... .



but when you say: "The VP-44 can only use/deliver so much fuel, no need to give it more than that. " I can't agree.



HOW do you know that for SURE? Have you tried to feed the VP with a high pressure like I did?



Often it's usefull to think out of the lines and rules.....



Marco

 

[MCummings]

Running 35PSI fuel pressure (25 @ WOT) I ran a 14. 3



Running 5-10PSI I was runing a 14. 4-14. 5



I believe running higher pressure will give you more HP,,, but it also wears out the pump, and will definatly make a hard to start, or no start condition, and an "easy stall" condition (WOT, to idle stalling)



55PSI?? That's pushing the limits. I stopped at 40PSI.



I know Diesel Dynamics tested to 60PSI without problems.



Brad told me the FASS will not live long at 30PSI,, so I have it cranked to only 25PSI.





I can't afford the risk of loosing another Injection pump I'm at 125k miles. Ruined my first pump at 75K,, and I'm on pump #5 right now.



Merrick

 

[Gary - K7GLD]

I feel safe in the "assumption" that the hard mechanical parts of the VP-44 can survive considerable more PSI than the stock setup delivers - it's the SEALS and soft parts that would most likely be at greatest risk if such high PSI was maintained over the long haul. Then too, engineers and guys who work on these pumps daily also caution that higher PSI will also "load" and overstress the mechanical parts as well, potentially leading to an early death...



Say Marco - why not do an independent study - run your setup for a hundred K miles or so, and let us know how it works out~

 

[Marco]

I quote myself here!

For you guys with "extreme" trucks. What about such a pump in parallel to the normal fuel pump(s)? You'd need only a couple of check valves in order to hook up the two systems together... At the track / Dyno whatever... with the flip of a switch...

Learn to read!



I didn't feel comfortable running that kinda FP . What I'm saying is to have two different pumps. Normal /daily driver AND a high pressure one for playing.



Marco

 

[Gary - K7GLD]

Oh, I can read just fine - but statements like:



======



"but when you say: "The VP-44 can only use/deliver so much fuel, no need to give it more than that. " I can't agree.



HOW do you know that for SURE? Have you tried to feed the VP with a high pressure like I did?"



======



MIGHT tend to sorta encourage casual readers to believe that present PSI/flow constraints as seen by most who have modded their fuel delivery systems can be exceeded with a high degree of impunity - a rather dangerous suggestion that could lead to expen$ive consequences if employed on a pump that was already marginal in it's internal condition.



My own recommendation - proceed with extreme caution and an open billfold if you plan any consistent VP-44 PSI operation above 30 PSI or so...

 

[Hohn]

Looks like it's time to re-read the "pumps, lines, what not" thread... ... .

 

[Gary - K7GLD]

The only related statement in that thread *I* recall, was that higher PSI such as Marco suggests, was done as a test with no immediate pump or related failure - but what was NOT stated, was for how LONG that PSI was in effect. Like I suggested, a long-term test would be in order before *I* would want to even come close to making such a suggestion regarding radical PSI increases...



I, for one, would sure hate for someone to try my suggestion like that, and immediately suffer a blown VP-44 - I would feel sorta responsible~



All I'm saying is, be VERY cautious when wading in uncharted waters - OR diesel fuel!

 

[Marco]

Gary,



Do you know in what forum we're in here?



No it's not the first time owners, it's the Competition forum. .



It's supposed that the people who play in here KNOW what they're doing.

The Hp race has begun a long time ago. Solutions have been developed, some worked some not. Some can be expensive... .

Who cares if you want to own the most powerfull ( or almost) truck in the world?



Got my point?



Marco

P. S. With high Psi FP the power gain IS there

 

[justinp20012500]

P. S. With high Psi FP the power gain IS there

So if I am reading this right... (This is just scepculation) If you plugged the outlet of the vp and just ran the fuel system full on to build how ever much pressure it could build for a single dyno run (Permitted if the vp would even hold up) you would see significant HP gains????????????

This could be interesting.

Pressure is a measurement of restriction of flow?? Correct???

 

[Floor It]

You can not plug the return line, even for a single run! There is more to it than that. You need the return to work to lubrcate and cool the electronics or its burn up time,even the shortest time. If I remember right if you plug the return up to try and keep the fuel in the VP-44 it wont even run for very long.



John

 

[MCummings]

Don't plug the return line,,, unless you like to run your truck without oil.



True, it is a measure of restruiction,, but even if you plug off a FASS< or OE lift pump,,,, a Fass will only got to it's regulated pressure, and a lift pump will only do ~25PSI if it's very healthy.



You need a pump with alot of GPH, and not too much pressure.



I have a hotrod VP44 sitting in my backseat right now... If we can take up a collection, then I'll run a high pressure pump on my truck untill the injection pump craps out, then we can see what it looks like. (I'll replace it with the HotRod. )



I'd prefer to p0ut the HotRod on their, and keep the one I'm running now as a backup, but, you show me the money, and I'll hold out my hand



Merrick

 

[justinp20012500]

Come on guys. I said it was all speculation!!! I would never do that because I drive my truck everyday.