Well, mounting them parrellel would not be putting them inline. It would put them side by side and allow twice the flow (theoretically). Basically, what you could do is run a single line from the lift pump that Y's off into 2 seperate lines going to each filter. This would give you 2 seperate but equeal restrictions, there for not increaseing the restriction since there are multiple outlets, and I believe it would actually increase flow this way with the same filter.<br><br>Mounting them in Series would put them inline and actually increase the restriction.<br><br>Maybe I'm wrong hear, but if I am I don't see how.

 

[quote author=Robert Venable link=board=8;threadid=15587;start=15#150229 date=1055870005]<br>Well, mounting them parrellel would not be putting them inline. It would put them side by side and allow twice the flow (theoretically). Basically, what you could do is run a single line from the lift pump that Y's off into 2 seperate lines going to each filter. This would give you 2 seperate but equeal restrictions, there for not increaseing the restriction since there are multiple outlets, and I believe it would actually increase flow this way with the same filter.<br>[/quote]<br><br>Sorry, I missed what you were saying (I read parallel, but thought series). You're right, parallel wouldn't increase the restriction any, but its a moot point as the factory filter and housing is good to about 55 GPH, which is more than enough with the stock VP44. The filter may become a restriction with one of the modd'ed VP44s on the market and a parallel system may become necessary.<br><br>Rod

 

STOCK? STOCK? Noo, I just know you didn't just say that. Who would do such a thing? LOL Stock.

 

[quote author=Robert Venable link=board=8;threadid=15587;start=15#150322 date=1055883379]<br>STOCK? STOCK? Noo, I just know you didn't just say that. Who would do such a thing? LOL Stock.<br>[/quote]<br><br> Well, actually the stock VP44 seems to be serving Nate pretty well. He's well past the 600 pony mark on the stocker VP44. ;D<br><br>Rod

 

Well, what about the new common rail models? Do you think they can do that with there stocker? (Which is the CP3 right? And if so, what does CP3 stand for?)<br><br>

 

I honestly don't know, although what TST is doing with timing/pulse width boxes is most certainly impressive (+200 HP, and they aren't out of room yet). Stack a fuel pressure box on top, and a good set of twins, who knows? The rail may need to swapped out before the CP3 becomes an issue.<br><br>And I haven't got a sniff what CP3 stands for. Crazy Pigeon 3? ;D<br><br>Rod

 

Let's hope it does not turn out to be Crappy Pump 3.

 

I have read about the CP3 (Compact Pump 3 stage Injections system)

 

Given that fuel (and liquids in general) are non-compressable, any heat gain in the fuel would have have to come from ambient effects such as heat gained through the plumbing in a hot engine comartment, and mechanical shear in the pumps, much like heat is generated in a torque converter. The ideal gas law, PV=nRT, does not apply to non-compressable fluids.<br><br>O.K., so I'm an engineer. Nobody's perfect.<br><br>100 Proof

 

Many threads posted on this one; but in a nutshell, &quot;Liquids are not compressable&quot; as stated before. The absolute job of the lift pump is to supply liquid fuel to the inlet port on the injection pump (free of air and slightly pressurized). Since liquids are non-compressible, it makes no difference as far as supply pressure to the injection pump for fuel pressure at say 9 lbs or 90 lbs. The injection pump is going to pick up the fuel and squeeze it into the injection lines by the same amount. As correctly stated probably somewhere in the thread, injection pumps require proper fuel FLOW to operate properly. Pressures are used to diagnose flow problems. If you have adequate fuel pressure at an idle (3 to 9 lbs), but drops off at higher speeds, then this points to a FLOW problem. So the basic statement remains true: &quot;Increasing the fuel pressure has no bearing on horsepower output, since liquids are not compressible&quot;. Actual horsepower output is governed by the injection pump, and the ability of the fuel system (lines and filters) to supply clean, non-aireated fuel to the injection pump. .

 

[quote author=Den052 link=board=8;threadid=15587;start=15#151332 date=1056066279]
So the basic statement remains true: &quot;Increasing the fuel pressure has no bearing on horsepower output, since liquids are not compressible&quot;. Actual horsepower output is governed by the injection pump, and the ability of the fuel system (lines and filters) to supply clean, non-aireated fuel to the injection pump. .
[/quote]

I used to feel this same way, until we actually got the PE4200 system working. It appears as though there is _something_ in the VP44 that wants inlet pressure above 12 or 13 PSI at WOT (as long as its enough flow at that pressure). On every truck that we've raised the pressure to stock levels (15 PSI), at the 13 PSI point, we've seen a sudden increase in WOT boost of 2 - 3 PSI. More boost = more power being put to the ground. We haven't had a chance to dyno anything yet, but the trucks have also felt snappier. On our own test truck, we noticed this effect, and we weren't starved for flow before the PE4200 went on it (we were running a Blue and a Black before, all at 10 PSI, and what should have been plenty of flow).

Other customers who are running our old Black system have reported that their peak boost came up as well, as long as WOT pressures were above 13 PSI.

Its strange, and we may be misunderstanding something about the old systems we had on the truck (maybe the Blue/Black on our test truck didn't deliver enough flow. Maybe the banjo system we used at the time was faulty, although we tried the Blue pump with the same -8 lines we are currently using. Maybe Martians sabotaged our tests.) We'll probably start messing with the current system and regulate pressure back to 10 PSI and see if our power drops again.

Rod

 

When I added a Carter HP4600 pusher pump, and bigger banjos, the pressures went to 20 to 22 psi at idle and 15 to 16 at WOT. There was no percievable difference in power from when pressures were 3 to 4 psi at WOT.

I understand that the VP44 is used on an Audi diesel application over in Europe without ANY type of lift pump.

 

Rod<br>I think that's Canadian Penquin ver 3 :

 

Well, I would like to state that since pressure is measured before some orifices within the VP44 we can assume that the pressure at this point can be translated to maximum flow rate through these orifices. At WOT these flow rates could be crucial to really satisfy the VP44s needs. <br>About those Audis: The VP44 is used on VW-Audi engines (TDIs) with a displacement of either 1.9 liters (4-banger ) or 2.5 liters (V6). The biggest engine AFAIK using the VP44 besides the cumins is the BMW 3.0 liter diesel. Hence the displacement per cylinder is at most half of what the Cummins is using. The VW-Audi TDis rev up to around 6k rpm and deliver their max. HP at 5500, where they are rated at 200hp max. So these engines will only inject less than the half amount per revolution than the stock Cummins. Therefore IMHO the internal lift pump of the VP44 can keep up in these applications. With the bombed Cummins we talk about delifering 4 -7 times more fuel per revolution than on the small ones. . <br><br>Just my 2c<br><br>AlpineRAM