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p-pump questions

1685 Views 11 Replies 7 Participants Last post by  kscumminsdriver
how much more hp does the p-pump make? does it run any diff? whats all do u have to change to do a p-pump on a 24v? what is the cost to do it? what are the good and bad about doing it???
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I'd be pretty surprised to find out there were horsepower gains just from converting from common rail to mechanical injection. To the contrary, common rail injection has two huge power-making advantages: 1) the ability to precisely deliver exactly the amount of fuel needed for a complete burn and 2) drastically improved fuel atomisation due to the very high pressure of the injection rail and geometry of the electronically controlled nozzles.

You see, a mechanical nozzle requires a certain amount of fuel pressure to open it, and so the p-pump creates a pulse in fuel pressure to the nozzle in order to let fuel into the combustion chamber. That means that at the beginning and end of the injection, as the nozzle opens and then again as it closes, there's a little sputter of poorly atomized fuel. Furthermore, the way the fuel volume is controlled is by increasing or decreasing the pressure. So there's a difference in engine efficiency depending on RPM.

In common rail injection, the fuel rail is at a constant, very high pressure. A solenoid opens and closes the nozzle extremely quickly, and since the pressure is constant during the whole time the nozzle is open, the fuel enters the chamber perfectly atomized and in a spray pattern engineered to optimize the shape of the flame front. The result is more power, better fuel economy, and lower emissions -- all at the same time.

The problem is, it's all controlled by a computer... which is programmed by an egghead at the Dodge factory, and then closed up tight. You can't get in. So you can buy a power chip, and there are things you can do with some of the sensors to "fool" the computer into giving you more power, but your options are limited.

Whereas with a p-pump, even though your starting point is lower on the power and economy scales, any dumbass with a pair of pliers can come up with ways to change the way it behaves. And, as it turns out, some folks are pretty darn good at figgerin out how to get more RPMs out of the engine, more fuel volume, etc. That's where you get the power from.

I'm glad you asked this question, because I'm really hoping there will turn up some fellas who have made this modification to their 24V engine and can shed light on how hard it was, how well it works, etc. Because 24 valves is great, but being able to drive underwater and not be stopped by EMPs is pretty cool too, I think...
 

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I'd be pretty surprised to find out there were horsepower gains just from converting from common rail to mechanical injection. To the contrary, common rail injection has two huge power-making advantages: 1) the ability to precisely deliver exactly the amount of fuel needed for a complete burn and 2) drastically improved fuel atomisation due to the very high pressure of the injection rail and geometry of the electronically controlled nozzles.

You see, a mechanical nozzle requires a certain amount of fuel pressure to open it, and so the p-pump creates a pulse in fuel pressure to the nozzle in order to let fuel into the combustion chamber. That means that at the beginning and end of the injection, as the nozzle opens and then again as it closes, there's a little sputter of poorly atomized fuel. Furthermore, the way the fuel volume is controlled is by increasing or decreasing the pressure. So there's a difference in engine efficiency depending on RPM.

In common rail injection, the fuel rail is at a constant, very high pressure. A solenoid opens and closes the nozzle extremely quickly, and since the pressure is constant during the whole time the nozzle is open, the fuel enters the chamber perfectly atomized and in a spray pattern engineered to optimize the shape of the flame front. The result is more power, better fuel economy, and lower emissions -- all at the same time.

The problem is, it's all controlled by a computer... which is programmed by an egghead at the Dodge factory, and then closed up tight. You can't get in. So you can buy a power chip, and there are things you can do with some of the sensors to "fool" the computer into giving you more power, but your options are limited.

Whereas with a p-pump, even though your starting point is lower on the power and economy scales, any dumbass with a pair of pliers can come up with ways to change the way it behaves. And, as it turns out, some folks are pretty darn good at figgerin out how to get more RPMs out of the engine, more fuel volume, etc. That's where you get the power from.

I'm glad you asked this question, because I'm really hoping there will turn up some fellas who have made this modification to their 24V engine and can shed light on how hard it was, how well it works, etc. Because 24 valves is great, but being able to drive underwater and not be stopped by EMPs is pretty cool too, I think...
The 1998.5-2002 24-valve is NOT a common rail injected engine. The VP44 operates much in the same way as the pre-94 injection pumps on the first 12-valves to be installed in Dodge trucks, except they have the benefit of computer control. The computer control allows adjustments for changes in the environment, on the fly timing adjustments, etc...however the VP44 doesn't operate anywhere near close to the pressures of a common rail system.

I do agree if swapping stock for stock, the P-pump will not give you an edge over the VP44. Modified the VP44 is most likely going to be the more street-able of the two. On the other hand it appears for all out performance the P7100 is going to outflow the VP44.

All computers installed in factory cars are closed up tight, doesn't mean they can't be broken into and modified. I would leave this to the professionals though. The VP44 is not any different. Give people enough time and they will be tuning the VP44 and Dodge ECU just like people have done with gassers.
 

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just p-pump it and enjoy, im making probably a little over 600 horse on fuel with mine and thats not even that crazy, im hoping that when i run water meth itll hit 700, the drivability is a little worse but i am assured that my pump isnt going to leave me on the side of the road:thumbsup:
 

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Ok, check this out.

Resoning behind it:Advantages of p-pumping - Competition Diesel.Com - Bringing The BEST Together

Tons of other info.P-Pump 24Valve - Competition Diesel.Com - Bringing The BEST Together

The simple answers are:

If you cant rebuild an engine you cant do it yourself.

If its a DD and you want over 300-600hp stick with the VP.

Its not cheap. Look to spend 3-5K at the begining. After I sold my VP stuff I spent $800.

You need to be well versed in these engines to be able to tune it.
 

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i went to the junkyard and got everything off a 12 valve and did the whole p pump swap for under 1200 bucks, you can barely buy a stock vp for that money, DONT goto a performance shop to get the conversion just rob the front cover, pump, cam, lift pump and misc lines off a wrecked truck then get the injection lines and CPS relocation bracket from haisley. keeps the price down
 

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Good stuff, guys... A couple more questions come to mind reading your posts:

- Has anybody ever heard about doing this mod to the 4B? I keep thinking the 6B might be a little too much for me, but the 4B too little... But if I had a 16V 4B and I could convert it to mechanical injection, I just might hop on that train...

- What about interchangeability of other parts between the 24V and the 12V? Like the head, for example... If a fella wanted to convert his 12V to 24V, could he achieve that by putting a 24V head on and switching out the camshaft? Or visa versa (dunno why somebody would want to go the other way, but...) Or are there some differences between the two blocks that prevent that? And what about the bottom end? Any differences in the crank, rods, pistons etc?
 

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BTW Nice post, kstinson.

Well I don't know about anybody else, but that clinches it for me... if I won't get the environmental and performance advantages of Common Rail, then I've got no use for computer controls...

kuz I think driving under water and being impervious to EMPs is cool. Rock on.
 

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Good stuff, guys... A couple more questions come to mind reading your posts:

- Has anybody ever heard about doing this mod to the 4B? I keep thinking the 6B might be a little too much for me, but the 4B too little... But if I had a 16V 4B and I could convert it to mechanical injection, I just might hop on that train...

- What about interchangeability of other parts between the 24V and the 12V? Like the head, for example... If a fella wanted to convert his 12V to 24V, could he achieve that by putting a 24V head on and switching out the camshaft? Or visa versa (dunno why somebody would want to go the other way, but...) Or are there some differences between the two blocks that prevent that? And what about the bottom end? Any differences in the crank, rods, pistons etc?
Cummins made a ppumped 4bt. If you had your hands on a 4cyl common rail it would be the same as doing a 24v.

12v and 24V use different pistons, injectors, injection lines. Heads will interchange on the blocks fine. CR head needs some mods to work though. Cams are all different due to fuel system and rocker ratios.
 

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The VP44 is not any different. Give people enough time and they will be tuning the VP44 and Dodge ECU just like people have done with gassers.
I disagree with this... the VP44 and the accompanying ECM have been in use for over a decade and none have come close to the fuel only power numbers of a P7100 or Common Rail...

The ECM is very limited... hence why the baddest of the bad downloaders on a '24 Valve' only pushes out an extra 65hp... I believe a fellow member here actually dissected a spare ECM and was able to obtain the fuel, boost and timing tables from it, modify them, install the ECM and saw similar gains to what a downloader will get for you... Some of the limiting parameters are hard coded into the ECM. That thread still exists somewhere.

The VP44 itself is also limited... it has it's own 'brain' that must be gotten around and in stock form, it just doesn't have the cc's available that a P7100 will. Even the Monsters, HRVP's, BD pump and Dragon Fire don't have the ability to push the fuel that a P7100 will.

Roachie and others makes some goods points... the swap isn't for everyone. You need to have some cash and some wrench acumen or you just need to have a lot more cash(so the 'pros' can do the swap). If you just want 400 ponies, you're better sticking with the VP... streetability is in the eye of the beholder but it will definitely be more streetable with the VP44....

Of course, I'm starting to put the pieces together to P-pump mine... :party018:
 
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