boosted fuel pressure regulator question?

[ia96svt]

installing a kb 2.1 on my car i was wondering should i run a vacuum line from

before the blower after the throttle body?
after the blower boosted area?
before throttle body?

fuel pressure regulator is a aeromotive adjustable

and can anyone tell me where the vacuum line that connects to the intake rite after the maf goes?

 

[mwolson]

You must hook it up after the blower so it sees vacuum AND boost. If you hook it in front of the blower so it only sees vacuum, when you go into boost, you will not see enough fuel pressure and you'll go lean.

If you are running an FMU (AKA FMB), I'd ditch it, and go for a custom tune. Relocate your IAT sensor to after the blower before you install the blower too. Here's how I did it: http://www.classictiger.com/mustang/IAT-IMRC/IAT-IMRC.htm

Set your FRP at 39PSI (you didn't really need an adjustable one.)

I have no idea what line you are talking about when you say, "the vacuum line that connects to the intake rite after the maf". FYI, that is metered air, not vacuum. Vacuum doesn't happen until after the throttle body. Got a picture?

 

[ia96svt]

love the write up thanks! blower manifold is already drilled for the iat sensor but sensor is trash

just saw a video its where the stock iat sensor goes now i feel dumb

 

[racecougar]

and can anyone tell me where the vacuum line that connects to the intake rite after the maf goes?

I have no idea what line you are talking about when you say, "the vacuum line that connects to the intake rite after the maf". FYI, that is metered air, not vacuum. Vacuum doesn't happen until after the throttle body. Got a picture?

It sounds like the line in question is the air inlet for the PCV system. If so, that line should run from the intake tube to the passenger side valvecover.

 

[ia96svt]

question on this again? if the fuel pressure regulator uses vacuum to run the pressure why would you run this to a pressured part?

 

[racecougar]

question on this again? if the fuel pressure regulator uses vacuum to run the pressure why would you run this to a pressured part?

The fuel pressure regulator is referenced to intake manifold pressure in order to maintain a steady pressure differential (delta) across the injectors. When it sees vacuum in the intake manifold, it reduces fuel pressure, when it sees boost in the intake manifold, it increases fuel pressure.

 

[ia96svt]

will it do this even if it is not a boost refrance regulator?

 

[ESVEETEE]

vacuum is negative boost. It's the same thing.

 

[racecougar]

will it do this even if it is not a boost refrance regulator?

As mwolson already answered, no, it will not. If you only allow the FPR to see vacuum, fuel rail pressure will not increase as you go into boost, and you'll go lean. The reference line to the FPR must connect to a port that is located after the blower so that the FPR sees boost and vacuum.

vacuum is negative boost. It's the same thing.

Exactly. Vacuum = negative pressure, boost = positive pressure.

 

[mwolson]

To convert between inches of mercury (inHg) and pounds per square inch (psi), use the formulas below:

PSI = -0.491154 × "Hg
"Hg = -2.03602 × PSI

So a vacuum of 22 "Hg * 0.491154 = -10.8 PSI (positive vacuum = negative boost)
Boost of 10 PSI * -2.03602 = -20.3602 "Hg (positive boost = negative vacuum)