CP4 Inlet Pressure Spec?

[Dan]

Hey guys!

I'm just curious if anyone knew for sure what the spec for lift pump pressure for the CP4 on my 6.7 would be? I'm currently bypassing the factor lift pump with a FASS 220gph at 55 psi.. FASS instructs the factory pump to be bypassed.

I heard some rumblings that 55psi could be too low and that the factory CP4 requirements, can someone please confirm or deny this please?

thank you!

 

[CATDiezel]

Hey guys!

I'm just curious if anyone knew for sure what the spec for lift pump pressure for the CP4 on my 6.7 would be? I'm currently bypassing the factor lift pump with a FASS 220gph at 55 psi.. FASS instructs the factory pump to be bypassed.

I heard some rumblings that 55psi could be too low and that the factory CP4 requirements, can someone please confirm or deny this please?

thank you!

IF nobody has an answer...

HS will certainly know... might even find it somewhere on there website. Just guessing.

 

[Powerstroked162]

IF nobody has an answer...

HS will certainly know... might even find it somewhere on there website. Just guessing.

Bentley should put you on the payroll, Justin!!


It's over 100psi iirc.

.

 

[CATDiezel]

Bentley should put you on the payroll, Justin!!


It's over 100psi iirc.

.

Thanks

I was beginning to think you should be on the payroll for CFD as much publicity as you gave them! LOL

The "other" Justin has an opening for a new "steve"

I will admit, I wish he had a different name... haha

 

[01PSD]

I've heard so many different numbers. Some say it's 60-70 psi. I've heard 115-120.... :shrug: :wtf: LOL

 

[Dan]

ok awesome!!! well if someone could tell me an exact min pressure i would love it! hahahaha

and I'm going to troll their website right now!

i guess part 2 to this post is going to be what lift pump will support that type of pressure? im guessing ill have to do filters in line with the pump at these pressures and flow rates...

 

[Dan]

I've heard so many different numbers. Some say it's 60-70 psi. I've heard 115-120.... :shrug: :wtf: LOL

x2...

google has nothing but confusion and i dont have the right connections w/ ford yet!!!

 

[CATDiezel]

The great part about PRESSURE is, lets understand PRESSURE first...

Lets use IF THEN logic

IF the factory pump pushing 65psi to ONE high pressure pump...
THEN its sufficient for the second pump also--AS LONG as it can maintain 65psi

Pressure is simply a "controllable" by-product of FLOW.


The only area where a higher pressure could IMPROVE the CP's ability to perform would be if the higher inlet pressure was needed due to spinning the CP pump faster than rated speed, then the fill times for the plunger/barrel would be a little off.

I'm sure the HS fellas have tested its ability on a dyno at some point and dialed in the inlet pressure needs. I'm willing to guess 65psi is sufficient. The biggest reason 65psi WOULD NOT be sufficient would be due to the lack of VOLUME from too small a inlet fuel supply line from the FASS or factory pump.

using 65psi as an example only, not factual reference for required psi

There I go cheerleading again.... dangit!

 

[Powerstroked162]

I've heard so many different numbers. Some say it's 60-70 psi. I've heard 115-120.... :shrug: :wtf: LOL

The low pressure fuel system is regulated at 110-120psi to the cp4. I don't have flow ratings on the stock pump BUT I do know it flows a hefty amount. They designed the LP system to cool the HPFP as well as supply it. Pretty neat actually. What I'm interested in knowing is what the workable supply pressure for the cp4 is. Finding a aftermarket pump to handle 100+psi and live a long life is gonna be non-existent.

That isn't from H&S though so it may not be right!..... LOL


.

 

[CATDiezel]

The low pressure fuel system is regulated at 110-120psi to the cp4. I don't have flow ratings on the stock pump BUT I do know it flows a hefty amount. They designed the LP system to cool the HPFP as well as supply it. Pretty neat actually. What I'm interested in knowing is what the workable supply pressure for the cp4 is. Finding a aftermarket pump to handle 100+psi and live a long life is gonna be non-existent.

That isn't from H&S though so it may not be right!..... LOL


.

bout time you figured it out! interesting on the "cooling" aspect of the reason for so much flow.

 

[Dan]

The great part about PRESSURE is, lets understand PRESSURE first...

Lets use IF THEN logic

IF the factory pump pushing 65psi to ONE high pressure pump...
THEN its sufficient for the second pump also--AS LONG as it can maintain 65psi

Pressure is simply a "controllable" by-product of FLOW.


The only area where a higher pressure could IMPROVE the CP's ability to perform would be if the higher inlet pressure was needed due to spinning the CP pump faster than rated speed, then the fill times for the plunger/barrel would be a little off.

I'm sure the HS fellas have tested its ability on a dyno at some point and dialed in the inlet pressure needs. I'm willing to guess 65psi is sufficient.

There I go cheerleading again.... dangit!

ok i agree 100%

the thing is, i have a separate FASS pump for the cp3.. so all i am worried about is, does the FASS in fact supply the pump with equivalent pressure that the factory pump supplies... i don't think FASS would overlook something like that..

 

[Powerstroked162]

Im suprised your fass hasn't tripped the engine PCM into power default. Anything below 58psi seen at the HPFP feed and the truck should limp.

.

 

[CATDiezel]

ok i agree 100%

the thing is, i have a separate FASS pump for the cp3.. so all i am worried about is, does the FASS in fact supply the pump with equivalent pressure that the factory pump supplies... i don't think FASS would overlook something like that..

Well, Real good question...

Here's another thought for rattling a brain.

With twin HPFP's, you have double the "flow capable capacity" therefore they are literally at HALF the workload they were before. Because chances are you are only going to spend 1% of your time where TWO hpfp's would even be needed.... The rest of the time they are just loafing around.

 

[Dan]

havent had a problem so far!!! ok so heres another thought... what about running fass pumps in series? supercharge the current fass with another fass? it works in hydralics and turbo systems all the time!!!

my factory fuel pump went mia...

 

[Powerstroked162]

I'm curious how your two Fass pumps are routed and what they actually are to be honest. I trust nothing that was done by CFD.

.

 

[CATDiezel]

havent had a problem so far!!! ok so heres another thought... what about running fass pumps in series? supercharge the current fass with another fass? it works in hydralics and turbo systems all the time!!!

my factory fuel pump went mia...

IF your going to run them in series you WILL need larger lines going to the fuel tank.

Even if you run them in parallel. Myself personally I would run them parallel and valved. IF one fails then you can completely bypass it and run on one.

I have a funny feeling one FASS will be enough volume for both HPFP's Remember your not TECHNICALLY using that much over what the factory pump can or could handle... So with one FASS your already beyond what you will probably need.

I am spitballing without any specs in front of my face... just going off of a corrupted memory! lol

 

[Dan]

Well, Real good question...

Here's another thought for rattling a brain.

With twin HPFP's, you have double the "flow capable capacity" therefore they are literally at HALF the workload they were before. Because chances are you are only going to spend 1% of your time where TWO hpfp's would even be needed.... The rest of the time they are just loafing around.

yes, thats if the workload is split between pumps.. witch I'm sure with HS tuning it is.. i was a little nervous where there was no "CP3 controller box" but the custom tuning for that system makes me less nervous!

basically the cp4 is relieved of workload therfore supply pressure is going to be less crutial.. as long as the barrels are filling up sufficiently!!!

did i understand that correctly?

 

[Powerstroked162]

You don't need a "control box" on the cp3 because they share the same operation and signal as a cp4.


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[4EverBoosted1]

Dan, This is exactly why I am running Morgans custom setup of two factory LPFPs. We did as much research as possible and came to the conclusion that there is not a FASS or AIRDOG in existence that can flow the numbers of the stock ford pump, especially not while maintaining the reliability. From our knowledge, the pump flows around 75 psi under WOT and drops down to 55-65 under idle. (Morgan come check me on this). Steve 110 is insanely high! I dont remember hearing about that. If you look at my build thread you will see my two factory pumps. They will both run up to the h&s kit where they will equalize within that filter and then feed the cp3 and the cp4. Our only concern (which is very small) is that the cp3 is getting a little too much pressure, but we will find out. H&S doesnt have a problem so we feel that it will work out nicely. Its simple, dual factory pumps put out more reliability, more volume, and more psi than an aftermarket pump.

Oh and I have the flu, so disregard anything in that paragraph that does not make sense... Im all HOPPED UP ON MOUNTAIN DEW! (nyquil).....

 

[CATDiezel]

yes, thats if the workload is split between pumps.. witch I'm sure with HS tuning it is.. i was a little nervous where there was no "CP3 controller box" but the custom tuning for that system makes me less nervous!

basically the cp4 is relieved of workload therfore supply pressure is going to be less crutial.. as long as the barrels are filling up sufficiently!!!

did i understand that correctly?

That's correct...

Man Im stepping out here, Steve probably knows a fair bit more on how its setup.

Logically thinking here, the ECM has no idea it has 2 hpfp's The wiring is running parallel to the second pump through a split harness adapter... They are both controlled the same with the same signal from the ECM.

The tuning is just adding high pressure where they probably couldnt before, but now can.

Your "STILL" calling for the same amount of fuel at X-rpm and X-pulsewidth,

They are just making sure your high pressure is maintaining its desired level.

The purpose of "DUAL FUELERS" is not so much technically a power adder as it is a support item so they can continue on with the injection event without delay.