An FPR question

[Phyxius]

If I have a megasquirt system, do I really need anything other than a 1:1 fpr? I've read in several places where people say that the other's are just a band-aid type fix for the lack of a good fuel management system.

 

A little background: I've completed my turbo, intercooler, and megasquirt upgrades, and now I'm looking at the fuel system. I have a pallnet fuel rail (not installed), walbro 255lph pump and am going to be using either 460cc or 570cc fuel injectors. I'm leaning towards the 570's.

 

edit: I can't seem to change the An grammar error in the title...that bothers me...lol

[SleeperZ]

Not running an FPR that delivers a constant pressure will cause havoc in any ECU where you have programmed certain duty cycles for cerain load conditions. If your fuel pressure varies, you will have to take that into account when programming the fuel maps.

[TimZ]

Not running an FPR that delivers a constant pressure will cause havoc in any ECU where you have programmed certain duty cycles for cerain load conditions. If your fuel pressure varies, you will have to take that into account when programming the fuel maps.

 

I think you meant to say that you need an FPR that delivers a constant pressure differential from manifold pressure (i.e., a 1:1 FPR), right?

 

Constant absolute fuel pressure (i.e., 40psi at the rail no matter what) is not what you want.

[Phyxius]

That's what I was thinking. You want the pressure differential (not the fuel pressure) between the manifold and the fuel injector to be constant. I was thinking that something like an 8:1 would just make it harder to tune and be unnecessary.