I was told that the fuel pressure is controlled by a regulator on the return line to tank. This regulator is controlled by the ECU.

Is this correct for a 2001 GT?


Also would you need a RRFPR for a blown application? Or is stock good enough?

What is the max HP the stock fuel setup can handle before it starts to runs lean?

 

Mustang23 is correct, the regulator is controlled by the PCM and delivers just enough fuel based on the engine parameters. The returnless fuel system is on 99 to present mustangs.

I believe that once you get close to 400hp, you will tax the stock pump. there are a few ways around this. Steeda now makes a dual pump for the returnless system, i believe it is good to 700hp (but i dont have a catalog around me so i cant confirm...check the website). the other option would be to convert to a return fuel system, which should be fairly easy. I have a 99 motor in my 98 car and am using the 98 fuel system (not to mention coil-pack ignition) with a return.

 

mustang23, all EFI setup have a return line, they have to.

I was told the 4.6 setup is controlled by adjusting the amount of fuel allowed back inot the tank, kinda like a bleed off of pressurized fuel back inot the tank and this is how it is regulated.


None of the Ford guys have any input?

Maybe just provide a link with the info.

 

that is how the older system sith a retur work,


new 99 up mustangs are returnless!


listen to them, they are correct...

alot of people have problems tuning the newer (returnless) fuel systems ... that's why you see 300hp mustangs running 42lb injectors!

 

99+ Mustang/Cobra have a returnLESS fuel system. Never bothered reading up on how it works because I have a return style setup Do a search on corral.net....go to the modular tech forums and do a search. You'll find the info you need.

 

I have been down this lonely road with the returnless. Its a bitch. Steeda is making a system to convert it return style and Aeromotive has a set up now too. I am running Aeromotive set up on my car, it can handle 1000hp.
Prior I had a 255 pump and 30lbs injectors and putting out 350whp and it was running lean. Tried tuning it with a chip and that didn't work out all that well. Then went to 42lbs injectors it worked pretty well, untill I started putting 12# of boost in the motor and bumped up the timing.
But as far as blower application all the kits provide you with what you need for your motor to handle the power, as soon as you start going over what comes with the stock kit, have fun.