I've searched but no1 seems to have a definite answer I'm looking for. I have a holly 255lph pump as well with vortech FPR. My gauge tells me the fuel pressure is at about 52 psi. The vortech optimizer attaches to the top hat of the stock FPR. I want to lower it back down to 38 psi like how it was before when I had the stock pump to idle smoother. I can just adjust the vortech FPR til I read 38psi on my gauge so I can have a good idle but the real question is
1. wouldn't it be pointless to lower it back down to regular fuel pressure reading, I mean that's the point of installing an aftermarket pump to get the pressure up for boost? I know the car would run rich at 52psi during idle but is there a way to alleviate it for a smoother idle. I've also read about drilling a hole on the FPR to relieve idle pressure. Would this be the solution to that? If it is then I can just leave it at 52 psi and just drill the hole right?

2. Even if I lower it to stock fuel pressure back to 38 psi, would my holly pump flow as much volume as it is when I had the FPR set at 52psi? car is a d-series with dsm 450cc +255 lph holly in tank fuel pump+vortech fpr/optimizer

3. would it hurt anything if i lower it back to stock fuel pressure even though i have a high flowing pump or is 52 psi enough?

 

I mean I dont see anything wrong with lowering it back down to 38 psi (stock fuel pressure) since I've read a lot of you FI guys leaving the stock FPR on.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BrokeAssPinoy &raquo;</TD></TR><TR><TD CLASS="quote">I mean I dont see anything wrong with lowering it back down to 38 psi (stock fuel pressure) since I've read a lot of you FI guys leaving the stock FPR on.</TD></TR></TABLE>


The intank pump flows alot more fuel than the stock pump. It is good to have so you wont starve the injectors for fuel.

 

I think your under the wrong impression here. ANY FPR/FMU works on vacuum pressure. Its not at one pressure all the time. At WOT (or boost) your fuel pressure is at its highest. When you adjust your FMU your adjusting the fuel pressure range so to speak.

So yes you can lower your idle static fuel pressure but that will also lower your WOT fuel pressure, which may or may not be good depending on your AFR during that period. This is why FMUs general suck because they only can be tuned for one or the other. Be careful, your idle may be smooth but your engine maybe lean during boost.

 

oh now i see your point

 

At this point your pretty much guessing. To do it right you need to have it tuned with a wideband to see how much fuel pressure to add/remove.

To be safe: keep it at 52psi

 

yeah I'm meeting up with a local who will tune with a wideband, i just got the turbo kit on and i havent ran the car since I primed it. Right now im on stock injectors but as soon as i meet up with him, he'll tune it with a wideband and he would install an safc2 for now. im still saving up for hondata