Tuning your Feul Pressure for PERFORMANCE
 

Hey all.

I have tuned a N/A car with a AdjustableFeul Preesure Regulator(AFPR)

We set the AFPR to standard 2.5 bar then we ran on dyno and it made the same power. Gewd. Then we Slowly increase the FP buy .1. power and torquw went up very Gradurly. then at 2.9 bar The power Dropped BIG time. So we set it back to 2.8 and left it at that! KEWL

anyway now im about to tune it on my turbo car. Spoke to a Guru last night and he said ajusting the FP will not Increase performance only control detonation, and he was adimant!

With a turbo car whats going happen? is there gonna be a point were the power Drops? or is the car just going to run execessivly rich?

Re: Tuning your Feul Pressure for PERFORMANCE
 

tune with real engine management if you want more power.

an fpr will only get you so far. and by far I mean it will get you rich and semi safe.

Re: Tuning your Feul Pressure for PERFORMANCE
 

Okie i understand adjusting the FP will only get you so far/is a very Small piece of the puzzle. i just want to get it right.

how do you know when you have gone to far? so okie i have a mangment system but it is set to super super rich and i dont know why. where would be a gewd place to start. reset the FP to stock and take it from there?

Im nervious cos Pinging/Detonating a turbo kar = big Kaboom

Re: Tuning your Feul Pressure for PERFORMANCE
 

Get a rope. "gewd", "kar", "KEWL" ::) :8

Re: Tuning your Feul Pressure for PERFORMANCE
 

get a wideband o2 sensor. tuning on the dyno for power is stupid without an AF reading.

Youd start rich, make power

lean it out, make more power

lean it out more, ,make more power

lean it out even more, start making more power then BOOM!

youd blow it up and bitch about how your engine blew up.

with forced induction, being leaner to the point right before detonation occurs will yield most power (in many cases) but its also the more dangerous place to be, any step leaner will result in knock and detonation.

Re: Tuning your Feul Pressure for PERFORMANCE
 

THE BOTTOM LINE IS I WANT TO RUN A NORMAL SAFE FEUL PRESSURE NOT Above 5

at the moment the car is setup to 5 and 5.5 Bars but the standerd car is only set at 3. what do you guys set yours to be safe +-. I do have Bigger Injectors and a managment to "Give " the car more feul. hence i dont need to do it from the FPR......

Re: Tuning your Feul Pressure for PERFORMANCE
 

Oh man, that is so wrong.

There is a point when you make less power by being lean and trust me it aint as lean as you might think.

Re: Tuning your Feul Pressure for PERFORMANCE
 

Hope you got the fire department on speed dial mofo.

80psi FP? What the ---- are you thinking??? If you gotta crank the FP up that much to get the car to run right, something is VERY wrong!!!
5bar is not safe at all. you really shouldnt exceed 3bar without having a fuel system that can safely support it, or an engine that needs it.

Tuning w/ just fuel pressure is dangerous and wrong.

Re: Tuning your Feul Pressure for PERFORMANCE
 

set pressure at 40~43 psi leave it alone, and add fuel through your fuel maps. If you don't have a tuning program running on your ECU then get one soon.

Re: Tuning your Feul Pressure for PERFORMANCE
 

Another problem to add to this debate is the fact of atomization...basicly reducing the fuel droplets to the smallest size possible to mix with the incoming air to provide the most complete and powerful combustion. This factor right here is why carbs are still king on high-power, high rpm n/a drag cars. People can argue that the fule injector itself does the atomizing, which it does to a point. Increasing fuel pressure does not increase fuel atomization, rather it decreases it by increasing the size of the fuel droplets...in order to provide more fuel. And seeing that the injector is placed so close to the ports on the head, it gives the fuel even less time to mix properly with the incoming air charge.
Of course running too low a fuel pressure will also produce the same results as too high a pressure, so it's a pretty thin line as to how far you can push your injectors. Stock pressure settings are usually the closest to best atomization, but you can go a little higher than that. It's best to tune fuel amount off the ecu with how long the injector stays open to increase fuel than to raise the fuel pressure itself.