BlownAlaskan

iTrader: (3)

I just got the injectors in and the wideband hooked up last night. Wondering what the optimum air/fuel ratio is? My Ltrims seem to be slightly negative so far. What is the next step for tuning?

I went for a short drive last night and noticed that when I am up to highway speed and let of the gas (4th gear), I went really lean. Is this normal? PE is kicking in at 40% TPS and then it is plenty rich. Ideas?

parish8

iTrader: (6)

sounds like you are close, lean is ok when the throtle is closed.

waht is your a/f ratio at WOT? how much timing are you geting? and most important are you seeing any knock retard?

basicly you want to adjust the pe vs rpm to get you around 12-12.5/1 a/f ratio, if you get there and see no KR then you could add a little timing or add boost. when you get to the point of seeing some KR then you back off on your settings a little or add better fuel.

Black Blown 02

I would shoot for 12-1 AFR at the leanest.Right now mines at 11.7-1. Also supposedly its good to go rich to lean from torque peak to hp peak, like 11.7-1 at 4200 to 12-1 at redline.

I think you're good with LTRIMS as long as they're at 0 at WOT, so they dont add any fuel to make tuning inconsistent.

Next, just adjust PE vs RPM to bring your AFR where you want it at WOT.

Its normal for it to go lean when you lift off the throttle.

What are you're MAF readings at redline in lbs/min? Just curious for comparisons sake.

You can thank Parish8 and XLR8NSS for this info, they're the ones that taught me.

XLR8NSS

iTrader: (4)

Check this thread out about the going lean after letting off the gas.

https://ls1tech.com/threads/showflat...=7&fpart=1

Oh and be careful listening to Black Blown 02 and parish8. Hehehehe...Just kidding.

Black Blown 02

Parish beat me to it!

parish8

iTrader: (6)

i am not sure on the "best" a/f ratio but when i asked around i was told 11.5-12 for non intercooled and 12-12.5 for cool air. i got those numbers from a few people.

definately keep us updated, especialy on the maf reading.

parish8

iTrader: (6)

yea, brain fart

BlownAlaskan

iTrader: (3)

ok. Ltrims are looking nice at like -2.xx. IFR=4.55. Can you guys tell me how to adjust PE vs RPM? Where is it in edit. Sam had me set it so that the truck goes into PE mode at 40% throttle. Does this seem good? What kind of adjustment to the values should I make to the PEvsRPM? Also, I should be able to get away with at least 12:1. Beacuse it is so freakin cold up here. My IAT is like only 50 deg or something crazy like that. Keep up the suggestions. I love it; this is fun!

parish8

iTrader: (6)

what are your WOT a/f ratios now?

go into the PE vs RPM chart and increse the numbers at the rpms where you want more fuel, and decrese the numbers where you want less fuel. the numbers you see in that chart are some kind of multiplier, i never really thought about it too much, just added fuel or took fuel away till it was where i wanted it.

if your a ways off on your a/f you might want to change a large section of the chart by something like 5%, then relog. seems like i stuck to 3000pm+ for my adjustments. by the time i was finished i was adjusting just a few cells by 1 or 2%. it is fun.

there is a scientific way to adjust your ratios and get really close the first time, i have seen posts on it, they were talking about making some excell program and charting the a/f ratio vs rpm and calculating the change, bla bla bla, it was over my head like many things around here. i had fun just changing it and retesting.

BlownAlaskan

iTrader: (3)

Hey Black,
Thanks for the tune, I couldn't read it though. Must be becuase I have the 99-00 version? Oh, and I lied. IAT is 100 Deg; My bad.