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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 1994 - 1995 Specific Tech

do i need an FMU w/ s-trim?

  • Thread starter Thread starter davins130
  • Start date Start date Jul 13, 2005

davins130

New Member
May 21, 2004
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Jul 13, 2005
#1
  • Jul 13, 2005
  • #1
what i need to know is if its neccecary to run an FMU on my car, its going to have big injectors and 255lph fuel pump on when the s-trim goes on and its getting tuned, and the only thing im not getting with my kit is the FMU, do i need it??(BTW i dont even know what it does)
 

FlyBy763

Member
Apr 23, 2004
439
0
17
Palm Bay, FL
Jul 14, 2005
#2
  • Jul 14, 2005
  • #2
you shouldnt need it if youre going with a 255 pump and like 42# injectors...basically what it does is raise the fuel pressure to make the injectors flow more so they act like a bigger injector.
 

Venom351R

Founding Member
Apr 27, 2002
4,548
41
98
MAINE
Jul 14, 2005
#3
  • Jul 14, 2005
  • #3
with enough fuel you dont need an FMU. Most people dont like to run one ( Including me) b/c an FMU is nothing but a band aid for a lack of fuel issue. W/ a 255 Pump and #42 injectors you wont need one.
 
G

Green 94 5.0

Founding Member
Mar 25, 2002
2,601
12
79
Ft. Lauderdale, FL
Jul 14, 2005
#4
  • Jul 14, 2005
  • #4
as was said above 255lph pump and 42's make the fmu unnecessary.
 

eschlenz

Founding Member
Jul 11, 2001
294
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0
Boulder, CO
Jul 14, 2005
#5
  • Jul 14, 2005
  • #5
Question

Question: If he's running a stock FPR won't that be his limiting factor?

I'm still a little new to the fuel pressure and the concepts, so call me on it where I'm wrong so I learn. But I know how a FPR and FMU work. So if he doesn't run an FMU or an adjustable FPR, where will the added fuel pressure come from?
 

tragikcomic

Founding Member
Sep 19, 2000
486
0
0
St.Louis, MO
Jul 14, 2005
#6
  • Jul 14, 2005
  • #6
eschlenz said:
Question: If he's running a stock FPR won't that be his limiting factor?

I'm still a little new to the fuel pressure and the concepts, so call me on it where I'm wrong so I learn. But I know how a FPR and FMU work. So if he doesn't run an FMU or an adjustable FPR, where will the added fuel pressure come from?
Click to expand...


Thats the thing with the larger injectors. With 42#'ers he won't need added pressure. The injectors will supply more fuel per pulse. You won't need to kick the pressure way up in order to squeeze out more fuel per pulse like you would with 19's.
 

eschlenz

Founding Member
Jul 11, 2001
294
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Boulder, CO
Jul 14, 2005
#7
  • Jul 14, 2005
  • #7
tragikcomic said:
Thats the thing with the larger injectors. With 42#'ers he won't need added pressure. The injectors will supply more fuel per pulse. You won't need to kick the pressure way up in order to squeeze out more fuel per pulse like you would with 19's.
Click to expand...

Cool, thanks for the reply! That's the part I was missing.
 

davins130

New Member
May 21, 2004
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0
Jul 15, 2005
#8
  • Jul 15, 2005
  • #8
thanks guys, one less thing i need to worry about.
 

BPA

Founding Member
Aug 5, 2000
159
0
16
S.F.
Jul 15, 2005
#9
  • Jul 15, 2005
  • #9
good luck with the install , im sure you will be happy with the setup let us know how it turns out for ya.
 
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