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LTFT Boundaries...what do they mean/control

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Old May 23, 2005 | 06:36 PM
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Default LTFT Boundaries...what do they mean/control

I see they exist...
but what are the boundaries for?? what do they control??

specifics please...

and why have I heard that it is good to set them to values like 1000/2000/4000 for RPM
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Old May 23, 2005 | 08:07 PM
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Id like to know the answer of this as well, as I dont understand the concept on this either.

Dixit
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Old May 23, 2005 | 08:34 PM
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From What I have read on a Post by Jimmyblue ,Changing these values to 1000/2000 and 4000 will give you a better veiw in covering the Majority of the cells...I hope this helps

Scott
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Old May 23, 2005 | 08:38 PM
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but can somebody explain how the zones work and why we need zones??
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Old May 23, 2005 | 09:21 PM
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i think it has to deal with how the fueling is broken down, into different catagories. the finer you make these areas the better the fueling will be. i noticed when i changed mine it was a lot easier to get the fuel trims in line, the 2000's are way out of wack
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Old May 23, 2005 | 09:28 PM
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Originally Posted by WS6FirebirdTA00
i think it has to deal with how the fueling is broken down, into different catagories. the finer you make these areas the better the fueling will be. i noticed when i changed mine it was a lot easier to get the fuel trims in line, the 2000's are way out of wack
If you dont mind my asking where was your boundries on 2000,my 99 was 900,1400,2200 so I moved mine to 1000.2000.4000,I was also told by doing this would help me in SD tuning
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Old May 23, 2005 | 09:30 PM
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they were like 2500,6200,6201 opr something way wacky...but mine are now 1000,2000,4000
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Old May 23, 2005 | 09:31 PM
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they were like 2500,6502,6503 i know the last two are right but the first one i could be wrong. i have them at 1050,2400,4000
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Old May 23, 2005 | 09:36 PM
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That is way wacky,I dont even see a reason to even have them.What the heck where they thinking?
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Old May 23, 2005 | 09:49 PM
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Scott ,Try this
https://ls1tech.com/forums/showthrea...highlight=ltft
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Old May 23, 2005 | 10:08 PM
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yeah i was having troubles a while back and after that post i changed some things and the car got a lot more consistant
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Old May 23, 2005 | 10:26 PM
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You have 16 cells available to trim closed loop
fueling. The less "space" any one has to cover,
the more accurate each can be. This is especially
true in areas where the airflow characteristics
change rapidly with RPM or MAP (like, say, the
low end on a big-cam car). What you don't want,
is one cell trying to comp out a wide space and
getting its value dragged up and down by driving
history, and always being late and wrong. This
is one thing that makes for bog-and-zoom engine
behavior on transitional throttle.

For my car I picked 1000, 2500, 4000 as these
seemed to fit my setup. But someone having a
low end drivability problem might want to crowd
it lower. The main thing is to get them all in play.
You might start by looking at the LTFT histogram
and position the boundaries so you have more cells
divvying up the area where you see the largest
trimming being done, or the area where the trims
seem to vary the most.
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Old May 24, 2005 | 04:12 PM
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That HelpsThanks ,jimmyblue
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