This may be something that has already been visited, but I was wondering if anyone has tried using an FMU setup and boosting fuel pressure in reference to boost. The factory ECU may not be as inclined to make the changes it does when a piggyback is used. I apologize if this is an old topic revisited, someone will let me know if it is I am sure.

 

This will not work unless you change the fuel system to a return style system.

-ZPI

 

even if you convert over to a return line setup your still gonna be limited to about 55psi max unless you remove the in tank regulator and replace it with something that will allow it to flow...when you pull the regulator out it wont pump fuel...tried that one a while back.

 

Is that what the stock regulator is set at? 55psi? If so, that is plenty enough for gobs of power. Taking out the stock regulator will stop the duel pump from working even with an aftermarket pump? One of the other guys by our shop is using an inline pump with a regulator. Seems to work great.

 

the stock regulator is limited to about 45 psi, with the adjustable FPR you can squeeze up to about 55psi. I ran a 255 lph walbro, i actually had to modify the sending unit to fit it, but to answer your question, no it will not pump without the stock regulator or something to block that port off.

 

Where did you run the return line to? I have held back on installing the Walbro unit I have because I dont want it to run so rich that I wont be able to get it running right. Sometimes under WOT, I run 10.5 afr and the car is slow.

 

aright here is the layout for the return line...I put a bulkhead fitting in the sending unit and attached the stainless braided fuel line. Ran that under the car and up into the engine bay to the FPR, then ran the line from the fpr to the end of the perrin fuel rail....as far as the 255 lph, yea its definitely overkill thats for sure.

 

How much fuel pressure were you running with the 255 pump?

 

53 psi

 

there are somesmart people on this site. nice to finally see on a forum

 

lol, no wonder it was so rich. WAs it still ____ rich when you brought the fp down? I would have ran 40-43

 

anytime I cranked it down the car would sputter and cut out