Do u need an inline fuel pump with a FMU?

What FMU calibration disc do u run with 370cc injectors?

I have heard diffent things...who can tell me the correct answers? not what they have heard, but what they are using or have done.
thanks

 

well with a fmu u need an inline puel pump. Inline's tend to handle more fuel pressure. depending on which one i think between 110 and 140 psi (estimate). and yes i had a inank and ran lean at 7psi and with an inline i was fine

 

what's your setup?

 

255lph intank...v-afc...FMU 12:1 (to big)(which one do i need?)...AEM FPR...370cc injectors

 

Well, In my opinon you don't even need a FMU. those 370cc's, pump and the AFC should be all you need. My friend uses that same setup w/ his turbo d16, he uses a missing link to bypass the MAP though.

 

i have a check valve (same concept as missing link). I was reading, and i think i need to use the 6:1 disc. i learned you should use that for 30-38lb injectors..370cc are equal to 35lbs. but i still don't know if i should use an inline fuel pump

 

I think w/ a 6:1 disk, a intank will be fine. I run 255lph, RC 440c's, and a S-AFC.

 

how do u idle with 440's? how much boost u run like that? no fmu?

 

straight answer

YES

Rob

 

I have 450CC injectors, afc, no FMU, no checkvalves or missing links, walbro intank 255, stock FPR, ~40psi fuel pressure at idle and around 67psi at 11-12psi boost. (a la afc hack) and its amazing. Idle is *almost* as good as stock.

liam

 

you DO NOT need an inline pump.with the larger injectors,you will have enough fuel.i would keep the 12:1 fmu.i had 440cc injectors,12:1 fmu,and walbro 317 pump and made 380whp.that was a previous setup and it worked great.

 

first things first,aem fpg is no good with a fmu,you will blow the diaphram at 75-80 psi,if your using a 12:1 with a base fuel presure of 40 you going to hit over 120 psi even just runing 7 pounds of boost,even if you go to a 6:1 at 7 pounds your pushing it.my set up is aem fpg which is also 1:1 ratio,370's,walbro 255 intank and vafc on a b16a3 with a small t3,from what ive tuned on it so far im fine according to my egt,i will be putting it on a wide band soon.what r u using to determine if your lean or rich?try to determine if you even need a fmu.

 

do you understand how an FMU works? its a rising rate fuel pressure regulator, it in turn squezzes the fuel to increas the pressure of it under boost. You need a high flow pump to prorery operate an FMU, we can argue for days about this. Perhaps on larger injectors you can get away with an fmu and a strong intank pump. I would not recomend it on stock injectors, you need an inline pump, flat out it creates more pressure than an intank. Its been argued before and there is allways going to be others that will still argue it. Put it on a wideband and i bet that you will run lean without an inline. My two cents take it for what you will....

Rob

 

I dont think that with only the 6:1 disk he would need an inline....if you are going to get the 370's, why not just go for the 450's and do the hack?? It would cost you a bit more, but it seems like it would be worth it

 

i allready have this setup...and allready have the 370's. I have a 12:1, but i've learned that is to much. i was thinking a 6:1 is what i need for the 370's. but i didn't know if i needed an inline fuel pump.


[Modified by Jtsintegra, 4:52 PM 11/4/2002]

 

6:1 FMU is what u need for 370's. if the net fuel pressure u r running is greater then the max fuel pressure on the intank pump then u should be running an inline.

 

yes,i understand how an fmu works!when i had this setup,it maxed out fuel pressure at 90 psi and the air fuel ratio maxed out at 12.5.and yes,using larger injectors make this possible.besides,he said he was using 370cc injectors.

 

okay


Rob