I was considering usuing a 6:1 FMU for my application, but I was worried if perhaps it's too low a rate? I intend on boosting about 8psi daily with this 6:1 FMU rate, 440cc injectors (tuned down by V-AFC) and an inline pump (gotta get rid of my intank Walbro). I figure my fuel psi to be around the 100psi mark with this setup, is that enough psi to properly supply the fuel needed? I know we wanna keep out pressure's down around the 90-100psi mark for the stock rail, so I thought this was a good setup but I'm so used to seeing people with 8:1+ FMU rates so I wanna know what you think about a 6:1 for this setup.. thanks!

 

Ok, since this question has gotten about 25 veiws and no reply's, how about this, an airtex inline pump.. with this I should be able to use an 8:1 FMU rate and have pressures around 120psi safley (or so I figure), think I should still go with a lower 6:1 rate? BTW this is for 8psi and 440cc injectors.

 

not sure where you're getting 120 psi from...

8 psi with an 8:1 would give you 64 psi of fuel pressure

8 psi with an 6:1 would give you 48 psi of fuel pressure

now with the 6:1, i don't even think you'll get any fuel pressure increase since your stock fuel pressure regulator will just provide the static fuel pressure...

440cc with 64 psi of pressure behind it is a lot of fuel...

mith consider going with 370cc and an 8:1 disk for 8 psi....
that'll run you rich still... but i think better for idling and for 8 psi...

now, 440cc and 8:1 disk.... at 80% duty cycle.... will take you far beyond 8 psi of boost...

 

Have you considered just getting some 440's, aem/bnm type fuel regulator with a Hondata unit? Much much simpler and reliable.

 

Well WOT creates about 40psi of fuel pressure, plus 8psi on a 6:1 FMU would create an additional 48psi for a total of about 88psi (plus a little more from what the high pressure pump delivers on it's own from what I understand) should keep me at about 90ish psi. This with 440cc's should be pretty rich, but again I can dial this down via my V-AFC, so about 90psi with a 6:1 FMU or about 105psi with a 8:1 FMU (40psi static + 64psi from the FMU@8psi = 104psi), which one sounds better to you to run with 440cc's?