Last value or average on Histogram??
Thread Starter
Staging Lane
Joined: Nov 2001
Posts: 74
Likes: 0
From: Burleson, Texas
Last value or average on Histogram?? Just a quick question - is it better to use the average values from the LTFT and STFT histogram tables or the last values? I am assuming average but just thought I would check. Thanks
Thread Starter
Staging Lane
Joined: Nov 2001
Posts: 74
Likes: 0
From: Burleson, Texas
Thanks, I believe I have been inadvertently tuning with my tables on minimum value. No telling how long I have been doing it and I just noticed today. Back to the drawing board...... 
If your LTFTs drift enough in a logging session that
average, min and max are substantially different,
you probably want to figure out why there is the
history-driven scatter. Some likely causes are
cold O2s (headers) driving mis-trimming, FTC
boundaries that are over-wide (one cell covers too
much space), I expect there are others.
In my opinion both fuel trimming and spark are
"one sided", or at least biased. I want to see no
LTFT above zero (so look at max) and no spark
retard (so look at max) etc.
I know there're some howtos out there that want
you to look at averages and I don't know why.
At best averages equal the normal condition but
averaging obscures detail.
average, min and max are substantially different,
you probably want to figure out why there is the
history-driven scatter. Some likely causes are
cold O2s (headers) driving mis-trimming, FTC
boundaries that are over-wide (one cell covers too
much space), I expect there are others.
In my opinion both fuel trimming and spark are
"one sided", or at least biased. I want to see no
LTFT above zero (so look at max) and no spark
retard (so look at max) etc.
I know there're some howtos out there that want
you to look at averages and I don't know why.
At best averages equal the normal condition but
averaging obscures detail.
consider this...
you can drive around and watch the STFT on Last Value....
when they are all around 0 then your LTFT's should be learned
which means you can then restart the logging process and do LTFT on "Average" settings...will make it easier to get the tune right the first time
you can drive around and watch the STFT on Last Value....
when they are all around 0 then your LTFT's should be learned
which means you can then restart the logging process and do LTFT on "Average" settings...will make it easier to get the tune right the first time
