do i need an FMU w/ s-trim?

[davins130]

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]

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]

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.

 

[Green 94 5.0]

as was said above 255lph pump and 42's make the fmu unnecessary.

 

[eschlenz]

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]

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?

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]

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.

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

 

[davins130]

thanks guys, one less thing i need to worry about.

 

[BPA]

good luck with the install , im sure you will be happy with the setup let us know how it turns out for ya.