fuel pressure: HELP!

[kylev90]

Putting in a Raptor lift pump and 2-micron CAT filter right now. How much fuel pressure should I set my Raptor to? What is required for these OBS?

[kylev90]

ok so heres my situation. Setting up my raptor fuel pump. Directions call to run my line from the raptor to my stock high pressure fuel pump on the frame rail. Problem is....there isnt one! Dunno if somebody replaced it with a different in tank sending unit or what but its definitly not there. Ideas? Also, once I figure out how to run this correctly does anybody know how much pressure is going to be needed from this raptor pump? Its rated for 50 PSI. Thanks everybody

[CT Performance, Inc.]

60-62 psi is what I've been told to set a regulator no less.

[Justin M]

Originally Posted by kylev90

ok so heres my situation. Setting up my raptor fuel pump. Directions call to run my line from the raptor to my stock high pressure fuel pump on the frame rail. Problem is....there isnt one! Dunno if somebody replaced it with a different in tank sending unit or what but its definitly not there. Ideas? Also, once I figure out how to run this correctly does anybody know how much pressure is going to be needed from this raptor pump? Its rated for 50 PSI. Thanks everybody

OBS trucks have a mechanical pump that is on top of the motor in the valley. There is no pump on the frame rail.

[kylev90]

right I knew about the mechanical pump in the valley but these guys at pureflow are swearing up and down there is one on the frame rail. And now they have no answers for me. So this pump wont build enough pressure for what I need then? Keep in mind im not deleting the mechanical pump in the valley. Just using this raptor in line with it.

[SuperDuty73]

I guess all you can do is put it on inline and hook it up to the existing lines. Run it and if you like it keep it otherwise take it off and replace with a new fuel line. Trial and error with the pressure. I'd hook it up how they said diregaurd the high pressure pump since our mechanical pump is a two way on pulls the fuel up to the motor and the top side pumps it at a higher pressure.
Put a gauge on the schrader valve on the side of the fuel bowl and messure your pressure. At idle no more than 75 psi and under WOT nothing under 62 psi. Id start low maybe 10-15 psi with the new pump and adjust as necessary.
Mark

[kylev90]

cool thanks mark. I will just keep an eye on everything then.

[kylev90]

so for sure nobody here with an OBS has a high pressure fuel pump on their frame rail? These guys at pureflow technologies are really pissing me off. So if there is no pump on the frame rail we have to have an in tank lift pump of some sort correct?

[kylev90]

ok got the fuel pressure guage in (which by the way HOLY NUTS! $215!!!) and seeing 30-40 PSI at an idle and 60 MAX WOT. Sound about right before the raptor?

[SuperDuty73]

The fuel pump in the valley of the motor is the lift pump/ high pressure pump all in one. Idle should be a bit higher around 50-60 psi stock. After the raptor it should be a little better but you most likely will have to shim the fuel regulator to fix that---FPR mod
Mark