98TAauto

iTrader: (2)

ok someone correct me if im wrong here but its quite a few posts in here about this..

LTRIMS dont really mean you are rich or lean, they are just what tells the PCM to add fuel at WOT or not. Correct?

Yes if LTRIMS are +20 at idle, then its lean there, but that doesnt mean a rats a** at WOT. All that matters is what they are right BEFORE it goes WOT. Correct? So if they are +20 right there then the PCM is gonna dump fuel because it thinks its lean. Correct? Now if they are zero then the PCM isnt gonna add any fuel, which could, note could be bad because you may be leaning out on top end and the PCM isnt dumping fuel.

I just know on atap, yes i know ATAP isnt 100friggin precent correct. But when my LTRIMS are +6 right before WOT then my 02's read .92-.94(rich). Now if they are zero, my 02's read .86-.87(leaner). Anyone have a answer for this?

maybe im wrong, so if i am could someone let me know

i'd just rather have a little positive LTRIMS so the PCM dumps fuel instead of not dumping some fuel to richen the car up a bit

AFTICA

iTrader: (8)

From my exhaustive research on this subject;

Ltrms do not mean your rich/lean. It tells you what the pcm is doing to keep a/f at 14.7. If you do something to keep the pcm from maintaining 14.7 it will throw a code.This is primarily in other than WOT, however positive Ltrms will add fuel at WOT so you want slightly negative Ltrms just before WOT. Set your a/f at WOT with the PE mode & make sure you have slightly negative Ltrms just before WOT & you will have a more consistant a/f at WOT.
The reason your getting richer WOT O2's when the ltrms are positive is because it's adding fuel.When it's zero or less it's not adding fuel, therefore the leaner WOT O2's. As I said above just make sure your ltrms are zero or slightly negative just before WOT & use the PE mode in Edit to make your O2's come out right. ( Whatever "right" happens to be. Need wide band to know for sure)

98TAauto

iTrader: (2)

thank ya.. exactly what I though..

so its really better for the backyard type tuner that doesnt dyno to keep then a little on the + side... like say +3 or so just to be safe <img border="0" alt="[chug]" title="" src="graemlins/gr_chug.gif" />

now if i went to the dyno, i'd want to get them to -3 so i can tweak my A/F in PE/RPM mode better!

AzzHauler

iTrader: (3)

Whether it's + or - just before the ltrims are locked in wot isn't really the important part. Making it consistent is the key. If you can get the part throttle parts smoothed out enough, so that every time you floor it the ltrims are always the same, then wot mode will be easier to tune since you won't have that variable. That is why you always hear to have negative ltrims. If they are negative, they will always go to 0 at wot. That way you can tune out of just the pe table. It's just less work to get the ltrims negative, since they can be anywhere in the -25 to 0 range to get a 0 ltrim at wot. And also a lot of ls1's tend to run a little better at a richer part throttle.

AFTICA

iTrader: (8)

Exactly as AZZHAULER said... Keep the ltrms zero or negative for consistancy.