catch_15

Lol...so i called my buddy who was with me and he said the 14.7 a/f was before they started actually tuning it....sorry guys...i'm still learning all this stuff. This is the first time I've ever seen this done in person. I don't know what the a/f is set at, but I do know that the car pulls like crazy compared to how it used to. It idles smooth as silk, and makes power all the way up to 6k rpm. I do know that my 24# injectors were running 85% duty cycle and my fuel pump is running 92% duty cycle.
Does anybody know what stock 98 fuel pumps lph output is?

Edit...if you watch carefully towards the end of my video, the a/f reading is 12.9 at the top right of their monitor.

teej281

Thats good then. Little aggressive but its fine. and if youre worried about the duty cycle of either, just get new ones. The injectors are probably screaming for dear life because you are probably running 19lb injectors, which on a stock PI GT were running at like 85-90% duty cycle. So you need to get some 24lb injectors and probably a new walbro in tank fuel pump, which is the same size pump as the focus pump, but its for return style fuel systems.

catch_15

I'm running 24# injectors...he said my 19s would have been maxxed out. Also, the 98s have a f****d up fuel system which is why I will wait until this pump kicks the bucket before replacing it.

teej281

Oh yea, the 98's had a returnless or something right??? And you should not be at that high of duty cycle honestly. Or at least i think you shouldnt.

catch_15

The 98s have a return style system but a pump more similar to the 99-04s...but the ECU regulates the voltage to the pump to control the pressure. It's basically a freakish mix between the pre 98 and post 98 fuel systems and is a pain to upgrade.

tbirdscwd

What have you done to your fuel system besides the injectors? Your car should have a return style system with a fuel pressure regulator. Your ECU shouldn't regulate the pressure like the 99-04s unless you changed something. The 24# injectors should be more than enough for the power you are making.

teej281

24's should be good for you, but the system in the 98's is different both from the 96/97 and the 99-04. Its an odd ball. They make different exhausts specifically for 98's and other things specifically for the 98, because somehow they are different than the 96-97 GT's. i have no idea why and i have no idea what gave the 98's 10hp more than the previous years either, but they apparently did. Odd ball car.

catch_15

Yeah, exactly Teej...it is an oddball and it's made everything a pain in the a**. From what I've researched (Izzy can probably clear this up for us) the ECU regulates the voltage on the fuel pump, which is why Walrbro doesn't offer a 255 for the 98s because they make gerator pumps that accept constant voltage, and not turbine pumps with alternating voltage.

boduke0220

Nice Numbers man! thats a clean looking car too, i have a thing for cammed GT's, whats next on the list?

catch_15

Upper and Lower control arms and some better rear tires :-)