I have been trying to figure out an optimal fuel pressure for my setup. I know that the going rate is roughly 38-42, but I just wanted to hear what some of you with the trick flow kit are running? My mods are in my sig.....I am running 39 now but I think I could probably go a pound or two higher, but I could be wrong. A dyno is definitely in the future and jrichker's SOTP meter is going to be used in the next couple days (very helpful, thanks), but just wanted to hear what others with similar mods are running. Thanks
Trick Flow setup...fuel pressure?
- Thread starter Rock777
- Start date
-86GTStang
Member
Fuelpressure..
I use 45, and 55 when racing. Timing set to 17dgr.
Think my engine like this setup. It works well with lower fuel pressure also, but the idle is better, and the trottle response feels great with 44psi. Never dynoed it, but tryed out different settings at the racetrack.. and a lot of normal driving, Just Me.
I use 45, and 55 when racing. Timing set to 17dgr.
Think my engine like this setup. It works well with lower fuel pressure also, but the idle is better, and the trottle response feels great with 44psi. Never dynoed it, but tryed out different settings at the racetrack.. and a lot of normal driving, Just Me.
Michael Yount
Mustang Master
Leave the fuel pressure at the stock setting 38-40. That's what the ecu and maf expect. The ecu has adaptive strategies that can alter injector pulse width in closed loop in response to the O2 signals. It will use this feature to keep the a/f ratio where IT wants it to be. So when you alter fuel pressure, as you drive the car, the computer is gonna alter pulse width to put things back where it wants them. You turn the pressure up or down so it injects more or less fuel; the computer simply shortens or lengthens the pulse width (time the injector is held open) to return things to where the ecu wants them. And it makes those changes fairly quickly. I suppose you could disconnect your battery to kill the computer's 'learning memory' each time you drive the car, but even then, any pressure change is only effective for a few minutes once you start driving the car. And, it also makes changes based on the same acquired data to the tables it uses to determine w.o.t. mixture parameters. So, over time, even when at w.o.t. in open loop, the ecu will work to get the mixture where it wants it notwithstanding your jacking around with the fuel pressure.
Get the car on the dyno at the stock pressure and get some real a/f ratio data. If it needs adjusting the way to do that is with a chip/PMS/twEECer/tuner. That approach will alter the parameters IN THE COMPUTER -- and those will stay altered. Playing with the pressure may be fun, and even yield a change in the short term (right after you start the car); but ultimately, the computer works to 'undo' your change.
Get the car on the dyno at the stock pressure and get some real a/f ratio data. If it needs adjusting the way to do that is with a chip/PMS/twEECer/tuner. That approach will alter the parameters IN THE COMPUTER -- and those will stay altered. Playing with the pressure may be fun, and even yield a change in the short term (right after you start the car); but ultimately, the computer works to 'undo' your change.
That does make sense, however what are the limitations of the computers curving ability. In other words, if I set the pressure to 25 or say 50, would the computer still manipulate the A/F ratio to where it needs to be? Other wise, what is the benefit of setting the fp between 38-40 if the computer is just going to "adjust" it where it needs it anyway? Not arguing, just trying to understand a little better.
Rock777 said:
I really don't think your car would run to well on 25 psi...
Anyways...I think as long as you stay around the "38-40psi" mark you will be fine...bump it up low-mid 40's and that should give you a pretty good a/f ratio at WOT...
I would try 86Gtstang's settings...I bet they would work just fine...
