Okay, i just got my turbo kit..and i have some quesitons. Well, i have a 255lph intank fuel pump from when i was nos direct port.. well, with my new kit, they included a inLINE fuel pump and a FMU. Now, should i use the inline as well with my intank? or should i take out the intank, and use the inline, or vise versa? either way, im gonna still use the fmu, but does the fmu require the intank pump?

 

since no one wanted to answer this... i will. with a fmu you only need the inline fuel pump + stock pump. you can keep the intank fuel pump if you like but i think it might be overkill, if you can take out the intank fuel pump yourself, might as well... sell it and have some extra cash for the extra gas you will be spending.

 

can i not use the inline? or do i have to..?

 

You need to use the Inline with the FMU. The intanks don't flow enough fuel at high pressure, at least the Walbro doesn't. (not sure about others).

 

well, mine is the 255lph, force induction version, and this is what it says on their web site:

"New this year are 255 liter-per-hour-rated "forced induction" pumps. These new pumps flow significantly more fuel at higher pressure. For example, at 80 PSI the standard 255 lph pump will flow around 132 liters (35 gallons) per hour. At that same 80 PSI the equivalent forced induction fuel pump will flow over 210 liters (50 gallons) per hour"

So i dunno guys, what should i do?

 

The problem with FMU's(especially the 12:1) is that they increase fuel pressure A LOT. Think about it. Let's say you're running 8lbs of boost, and your fuel pressure at idle is 35psi. Under full boost your fuel pressure would be 35+(12x8)= 131psi. That's what you need the inline pump for.

 

You can run only on the inline if you like. Just fabricate a pickup in place of the intank pump.

 

what about if i am boosting 15 to 20 psi and i have 450cc injectors out of a dsm what disk should i use and i have an intank in so far so good

 

Does the walbro tell you what is flows at 120psi? If it does it will say ZERO. So use the inline with the intank pump together. Unless you have some sort of stand alone and larger injectors stay with the intank. But since you have the FMU you NEED the inline.

art

 

I heard alot of people use the 255 high flow intank pumps for turbos with FMU's then the inline. A lot of people I see like the intank pumps better and suggest that instead of the inline. I thought the 255 pump was the way to go for the FMU setup so you can sustain that much fuel pressure. If the intank and the inline are the same flow rates, then wouldn't they just be the same, but the inline is easy to install.

 

Damn..i see.. but i was thinking...intank, plus inline.. fuckk..would be over kill.. i guess i'll try it..and see how it goes.. if its too much..then ultimatey, i must take out my intank, but the stock in, and run inline.. sound good?

 

good luck boostin 20 psi with fmu and intank.......

 

yeah keep them both, if its too much then take the intank out and just runthe inline..

 

See if you can dig up anything with the search, theres been numerous discussions about this. Or just read Arts post.


[Modified by Devin, 10:07 PM 5/15/2002]

 

fmu = inline... pull the intank for me seriously

 

How much would one excpect to boost with the sotck and inline pump with an FMU setup? Would you get away with using the 12:1 with the stock injectors? and what are its limits

Does it really make that much of a difference? Smoother power with no detonation or what

 

I boosted 8lbs daily for a over a year and a half with just a 12:1 FMU and my stock pump and I didn't detonate or anything, but when I hooked my a/f up, I was running severely lean under boost. Finally got my inline in, and not it's kinda rich under boost.

 

insypral, where you using your stock injectors with the FMU and stock fuel pump?