>95% Injector Duty Cycle?

[Main_One]

Thanks for the info guys!

WS6 - I agree totally with you about the wideband. I just talked him into getting his own copy of HPTuners, (our trucks are similar but different years), it probably hasn't arrived yet, and I've been trying to talk him into the wideband as well since with the boost he is running he really doesn't want to risk getting it wrong.

Romans - thanks for the info on what you are doing. Sounds like the setup you had is similar to what he has now, and what you have now is likely what he will soon be trying.

SRP - big thanks for noting that 100% is 100% of a crank revolution, so I guess that theoretically they could go up to 200%, but as you note, 80% is about as high as one would want to go.

Again, thanks for all of your good info!

Greg

[KY_BOB]

100% duty cycle means the injectors are on 100% of the available time. 100+% = STATIC, the injectors are wide open. At this point you are hoping the FMU is giving enough pressure that you aren't leaning out, but the ecm has lost all control. I had this on a 5.3 with a Vortech and FMU. We took the FMU off, istalled a set of SVO 42's and I was able to get the WOT AFR's to about 12.2 to 1 and not hit over 80% duty cycle. (We had to install a bigger fuel pump too)
Mark

I'm the friend that Main One is talking about.

Mark, could you give me some more details on the setup that you had. How much boost, and what disk you had in you FMU?

I have a set of 42# 8.1 Marine injectors that I plan on installing soon after getting HTP. (Hopefully I'll get it tomorrow.) I'm concerned that the 42#'s won't flow enough at stock fuel pressure, as I'm running 10# of boost. Would it be a good option to leave the FMU inline but go to a much smaller disk in it, like having it ramp up to 75-80psi at full boost?

Any input is appreciated,
Bob