adjustable fuel pressure regulator

[hondaetr]

continuing ed...

because 8 ). Gotta put a space in there.

To find the new flow rate, I take 23# @ 43 PSI for example, and at 55 psi it will be ( 23/43 ) * 55.

Almost, take the SQUARE ROOT of ( 55psi / 43psi) which is 1.130959 X 23#= 26.012057# new flow rate
These calculations were actually from Jeff Hartman's "How to Tune and Modify Engine Management Systems".

Thanks for the "space" 8 ).

[JMo60]

if fuel pressure doesnt affect feul output greatly, why do rising rate regulators work for turbo engines?. i thought that it was to increase fuel in proportion to boost.

What other ways would you recomend to tune fueling besides the computer? use larger injectors?

Another thought, would it be worth while to use 3400 multec fuel pressure regulator with the older 3100 style injectors and rail? because the multec injectors operate off of a higher pressure, would that regulator work to raise fuel pressure?

[AaronGTR]

They work if the injectors aren't close to maxed out and the fuel pressure isn't too high to begin with, and mainly they are used when you aren't running a lot of boost (5-8psi max). In that situation you only need a little more fuel, and you can raise the pressure without stressing the pump and injectors too much. Otherwise if you are planning on running higher boost and/or the injectors or fuel pressure are already running high, then it's time to upgrade because a simple RRFPR won't cut it.

[JMo60]

so, my next option for fueling may be an apexi afc, if the regulator thing wont do it right. Maybe ill invest into an afc and a wideband to tune it good. How much of a benifit will tuning with an afc actually do? is it even worth while?

[Fiero11]

The LT-1 has the mounting hole on the wrong side. Jegg's has an Aeromotive adjustable alumininum regulator that is the proper fitting part.

027-13107 Aeromotive adjustable fuel pressure regulator. $154.99

I have one and it is a perfect fit.

[AaronGTR]

so, my next option for fueling may be an apexi afc, if the regulator thing wont do it right. Maybe ill invest into an afc and a wideband to tune it good. How much of a benifit will tuning with an afc actually do? is it even worth while?

The AFPR would still be useful though. Your system is speed density right? (MAP sensor but no MAF sensor) If so, then the AFC should work. It just won't work on the newer GM obd2 computers with MAF sensors because GM MAF's use a Hz signal that isn't compatible with the AFC. It should work with the MAP only system though and it would definitely be useful for adjusting fueling.

[hondaetr]

if fuel pressure doesnt affect feul output greatly, why do rising rate regulators work for turbo engines?. i thought that it was to increase fuel in proportion to boost.

What other ways would you recomend to tune fueling besides the computer? use larger injectors?

Another thought, would it be worth while to use 3400 multec fuel pressure regulator with the older 3100 style injectors and rail? because the multec injectors operate off of a higher pressure, would that regulator work to raise fuel pressure?

Do not "TUNE" using fuel.... adding fuel and not tuning with computer is like using bigger carb jets and not adjusting the emulsion bleeds, not good and will either over/under fuel at part throttle or under/over fuel at WOT. You will sacrifice somewhere in the RPM band. FMU or regulators that are boost referenced add fuel in proportion to boost, because nat. asp. is at 1 pressure but the boost will require at lest 2psi/lb boost. this is because first to overcome added plenum pressure resisting injector spray, then added fuel requirements per psi. Put 6lbs boost into a carb enclosure and use a low pressure 6lb pump you will EQUALIZE the pressure in the bowls and STOP fueling all together. YES the injected engines are higher pressure and YES the "bowl" is actually the regulator. This is why the FPR and/or the FMU and the pump should work in tandem.