When's MAFT switch between base and WOT?
Thread Starter
TECH Apprentice
Joined: Jul 2002
Posts: 393
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From: Tucson, AZ
When's MAFT switch between base and WOT? Few questions about MAFT (sorry search didn't help):
1) Does anybody now exactly when MAFT (v.4.0) switches between base and WOT settings? I assume that happens when the reading from MAF reaches a certain constant (g/s)?
2) When MAFT thinks you are at WOT (and makes WOT corrections), are the base corrections neglected or not? I.e. if the base=+5%, and WOT=+2%, would the actual correction to MAF reading at WOT be +7% or +2% ?
3) Some people wrote certain tuning procedures for MAFT. They claim that base settings relate to cells 1-19 and wot - 22. Obviously MAFT has no way of knowing which cell the engine is using as it doesn't know readings from other sensors, and so I can only accurately tune for one cell [aside from #22]. Can anybody confirm that and elaborate on what cells would be best to use for max power (i.e. when you roll off the line at 2-4k rpm but are not WOT yet)? Currently I have some hesitation at ~3krpm - it appears when I reach about 3-4krpm, the car jumps slightly like a turbo car when turbo spools up. I'd like to make power delivery smooth, if possible. Thank you
1) Does anybody now exactly when MAFT (v.4.0) switches between base and WOT settings? I assume that happens when the reading from MAF reaches a certain constant (g/s)?
2) When MAFT thinks you are at WOT (and makes WOT corrections), are the base corrections neglected or not? I.e. if the base=+5%, and WOT=+2%, would the actual correction to MAF reading at WOT be +7% or +2% ?
3) Some people wrote certain tuning procedures for MAFT. They claim that base settings relate to cells 1-19 and wot - 22. Obviously MAFT has no way of knowing which cell the engine is using as it doesn't know readings from other sensors, and so I can only accurately tune for one cell [aside from #22]. Can anybody confirm that and elaborate on what cells would be best to use for max power (i.e. when you roll off the line at 2-4k rpm but are not WOT yet)? Currently I have some hesitation at ~3krpm - it appears when I reach about 3-4krpm, the car jumps slightly like a turbo car when turbo spools up. I'd like to make power delivery smooth, if possible. Thank you
People from ramchargers perhaps? They still sell it... except people have little idea of how it actually works... Please, share 
Thread Starter
TECH Apprentice
Joined: Jul 2002
Posts: 393
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From: Tucson, AZ
Originally Posted by jimmyblue
A web document I have sez 8kHz transition,
or roughly 70-75% of full scale mass airflow.
or roughly 70-75% of full scale mass airflow.
I got it off vetteguru.com, way back; looks like it's at
http://www.vetteguru.com/mods/maf/
Some mention there about abrupt / "jerky" behavior due to
poor supply decoupling on older models, as well.
also
http://www.ramchargers.com/RamNews/T...tor_manual.htm
for the basics.
What I see sez the base setting is a straight scaling on
frequency across the full range, with the WOT kicking in,
higher, as another "adder" to that (though the exact
math is a bit unclear, the base is said to be applied
always).
http://www.vetteguru.com/mods/maf/
Some mention there about abrupt / "jerky" behavior due to
poor supply decoupling on older models, as well.
also
http://www.ramchargers.com/RamNews/T...tor_manual.htm
for the basics.
What I see sez the base setting is a straight scaling on
frequency across the full range, with the WOT kicking in,
higher, as another "adder" to that (though the exact
math is a bit unclear, the base is said to be applied
always).
Thread Starter
TECH Apprentice
Joined: Jul 2002
Posts: 393
Likes: 0
From: Tucson, AZ
Thank you. That is definitely useful.
Originally Posted by jimmyblue
I got it off vetteguru.com, way back; looks like it's at
http://www.vetteguru.com/mods/maf/
Some mention there about abrupt / "jerky" behavior due to
poor supply decoupling on older models, as well.
also
http://www.ramchargers.com/RamNews/T...tor_manual.htm
for the basics.
What I see sez the base setting is a straight scaling on
frequency across the full range, with the WOT kicking in,
higher, as another "adder" to that (though the exact
math is a bit unclear, the base is said to be applied
always).
http://www.vetteguru.com/mods/maf/
Some mention there about abrupt / "jerky" behavior due to
poor supply decoupling on older models, as well.
also
http://www.ramchargers.com/RamNews/T...tor_manual.htm
for the basics.
What I see sez the base setting is a straight scaling on
frequency across the full range, with the WOT kicking in,
higher, as another "adder" to that (though the exact
math is a bit unclear, the base is said to be applied
always).
