Adjustable FPR Unnecessary???

JasinC19

What hole is this!?!

Jun 7, 2011

312

2

19

Mar 8, 2012

#1

• Mar 8, 2012

• #1

Well the first startup of my build is getting closer, so I was reading up on what I should set my fuel pressure to initially for my mods:

TFS Top End Kit, 255 fuel pump, 75mm throttle body, 24# injectors, and a calibrated MAF.

Everyone is saying to set it for stock 39psi! So why are these things even necessary?

Other than looking freakin sweet

 

txstang84

15 Year Member

May 21, 2005

1,639

42

69

Tuscola, tx

Mar 8, 2012

#2

• Mar 8, 2012

• #2

It'll help you to get things running up and smoothly-idle mixture sometimes plagues people running aftermarket meters and bigger injectors...then when you tune it, you set it back to factory pressure.


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JasinC19

What hole is this!?!

Jun 7, 2011

312

2

19

Mar 8, 2012

#3

• Mar 8, 2012

• #3

So if I have issues getting her started, try bumping up the pressure a bit?

 

Rick 91GT

Mustang Master

Nov 29, 1999

9,692

95

99

PA

Mar 9, 2012

#4

• Mar 9, 2012

• #4

The only place the adj fuel pressure reg will give you more fuel is at WOT when the vac drops out. Otherwise the stock EEC will modify the injector pulse width based on the feedback from the O2 and various sensors to get the A/F in check. If you need a little extra fuel up top, that is where they help but with a tune/chip they will add fuel through the program.

Set it to 36-38psi vac off...you'll be fine.