Adjsutable Fuel Pressure regulator worthwhile

[Ford Tough]

Is a adjustable fuel pressure regulator worthwhile for a bolton car?

 

[brad94GT]

yes

 

[MustangChris]

my friend with a bolt on 94 mustang benifited from it... he slapped a gauge on his fuel rail and found out he was 10psi under stock... (they dyno said they wouldnt let him run his car on it after the first pass because he was "so lean he was on the verge of blowing the motor.")

i would suggest it... easy bolt-on that can make life slightly easier.

 

[NERD]

It depends on what your injector duty cycle is at.

 

[Ford Tough]

So then it is not true that the computer compensates for the higher pressure by changing the injector pulse?

 

[NERD]

The eec controls it but not automatically. It's given a set value and adjusts off a mathematical calculation based on static inputs. What tuning software are you using?

 

[Ford Tough]

The eec controls it but not automatically. It's given a set value and adjusts off a mathematical calculation based on static inputs. What tuning software are you using?

I don't have any tuning software.

 

[NERD]

Your fuel pressure is static and you can have a little breathing room by increasing pressure but don't try going from 30 to 45 or anything crazy. Do you have a wideband? If you don't, I wouldn't mess with it yet.

 

[Ford Tough]

I am thinking about getting a wideband. From what I found online I need to set my pressure at 42psi with the vacuum line off.

 

[toyman]

Factory spec is 35-40 psi KOEO and 30 - 45 KOER. Setting it at 42 psi is on the high side.

 

[MustangChris]

whats KOEO and KOER?

 

[Ford Tough]

Key on engine off
Key on engine run

 

[MustangChris]

thanks

 

[wayne94mustang]

Factory spec is 35-40 psi KOEO and 30 - 45 KOER. Setting it at 42 psi is on the high side.

maybe for your car, mine likes the higher 40s.

there is no real rule to what a given car likes other then to try different settings.

 

[toyman]

Factory spec is 35-40 psi KOEO and 30 - 45 KOER. Setting it at 42 psi is on the high side.

maybe for your car, mine likes the higher 40s.

there is no real rule to what a given car likes other then to try different settings.

Are you running a tuner chip? If you are running high 40 psi then you're forcing more fuel through the injectors at any give pulse width all other things being equal. Under normal circumstances the ECU will adjust the injector pulse width to maintain the commanded AFR. The exceptions will be WOT or an altered fuel map with a chip. Just curious as to what makes yours run better at the higher fuel pressure.

 

[El_Diablo]

more pressure is sometimes needed for larger injectors to make them act like they should

 

[blackpony]

I would recommend checking your fuel pressure first off. If it is about 40 lbs with the vaccum off, then dont waste your money. Mine started leaking the other day and i put the stock one back on, runs better then it ever has....

 

[Paul]

more pressure is sometimes needed for larger injectors to make them act like they should

Huh? Why is that?





Anyway, normal factory is 39psi with the vacuum disconnected. Per what has been said above, at part throttle, the computer will attempt (within given parameters) to adjust the amount of fuel that gets injected in order to meet an air/fuel ratio target. However, at wide open throttle, the computer resorts to pre-programmed fuel "maps" and doesn't continually adjust pulsewidth. Higher fuel pressure in this scenario would ultimately mean more fuel, and to an extent, maybe more power depending on what AFR you're at when WOT. However, it's been my experience that the WOT maps are more rich than your normal burbling-around-town AFRs.

Long story short, you can try it. It doesn't hurt and the cost is relatively low. That said, there is definitely other stuff you can spend your money on first.

Paul.

 

[El_Diablo]

paul, typically its not the case with injectors for our cars but some injectors call for higher pressure to reach a given flow rate.... this can work the other way around aswell, i believe its the ls1 series injectors that operate at a lower pressure, something like the low 30's, bump this up and you go from 24's to 28's.... pressure rating directly relates to flow rates of injectors so make sure your pressure is dialed into what the injectors call for

 

[Greg_D]

I would suggest CHECKING your fuel pressure and run it stock, i bought one i have 32lbs injectors and i need WAY more fuel and it didnt give me any diff with little adjustments. NOT FOR TUNING get that straight!