Hey, do i need to adjust the aftermarket FPR if i'm using a FMU? Like, if i turn up the pressure on the FPR, and my FMU is 12:1 then, overall..thats more fuel right? From what i'm thinking, i just need to adjust the fpr for when it's 0 boost right? Then from there on, the fmu just takes over right?

 

You are correct. The FPR will adjust fuel from 30 "/Hg to 0 "/Hg and the FMU will adjust from 0 psi to whatever. The FPR will raise the pressure with boost, but at a rate much less than the FMU, so it is negligible.

So to set the FPR, disconnect the vacuum line and adjust it.

Randy