Re-calibrate the MAF??
#1
TECH Resident
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Re-calibrate the MAF??
I took the MAF screens out when I first bought this car and put on the Y pipe dual air cleaners. Installed headers next, and now a new motor with a good cam. Before I get started with SD tuning, do I need to re-calibrate the MAF? How do I do that.
Thanks
Thanks
#2
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If the pipe is straight then you don't need to do anything.
But I've seen references to 'vette and truck guys picking
up some lean error from descreening on occasion.
SD tuning doesn't need you to do anything with the MAF.
It bypasses it.
You have a lot of engine airflow & fuel delivery mods and
it would be difficult by this point to say, what portion of
any A/F error is attributable to the MAF's calibration. The
best bet might be to find and swap on a screened end for
the purpose of accumulating a baseline set of data, you
can presume the screened MAF matches stock table pretty
well. You would ideally like some street and WOT logs with
wideband data showing AFR commanded and AFR measured
along with MAF frequency and airflow.
Then substituting back the descreened end, more data will
show any deflection in your measured AFR and you can
ascribe all of the drift to the MAF and correct it point-by-
point at the logged frequency, by the ratio of (descreened /
screened AFR). That is, if descreened shows leaner then
you will be increasing the reported airflow and driving more
fuel into the system for the same actual air (frequency).
That's a fairly involved bit of data-taking and -crunching but
probably the straightest way to the MAF itself.
Then again, if it ain't broke, don't fix it.
But I've seen references to 'vette and truck guys picking
up some lean error from descreening on occasion.
SD tuning doesn't need you to do anything with the MAF.
It bypasses it.
You have a lot of engine airflow & fuel delivery mods and
it would be difficult by this point to say, what portion of
any A/F error is attributable to the MAF's calibration. The
best bet might be to find and swap on a screened end for
the purpose of accumulating a baseline set of data, you
can presume the screened MAF matches stock table pretty
well. You would ideally like some street and WOT logs with
wideband data showing AFR commanded and AFR measured
along with MAF frequency and airflow.
Then substituting back the descreened end, more data will
show any deflection in your measured AFR and you can
ascribe all of the drift to the MAF and correct it point-by-
point at the logged frequency, by the ratio of (descreened /
screened AFR). That is, if descreened shows leaner then
you will be increasing the reported airflow and driving more
fuel into the system for the same actual air (frequency).
That's a fairly involved bit of data-taking and -crunching but
probably the straightest way to the MAF itself.
Then again, if it ain't broke, don't fix it.
#4
TECH Resident
Thread Starter
Thanks guys, it sounds like mission impossible to re-tune this MAF especially with edit.
I will just trust that it is OK. I need to work on my VE tables to get this thing to run smooth 2000-4000. It is sluggish down there.
I will just trust that it is OK. I need to work on my VE tables to get this thing to run smooth 2000-4000. It is sluggish down there.
#5
8 Second Club
iTrader: (16)
If you can log MAF HZ, LTFT, and STFT... and export them to a log file(excel spreadsheet style)
then you can use my spreadsheet to calibrate MAF...
http://www.audiohelix.com/hptuners/M...-Worksheet.xls
It has worked great for myself and many others on here
then you can use my spreadsheet to calibrate MAF...
http://www.audiohelix.com/hptuners/M...-Worksheet.xls
It has worked great for myself and many others on here
#6
TECH Resident
Thread Starter
Thanks for the MAF chart. My trims are off and my motor is so far from stock that I would probably not get the MAF calibration right. It sounds like a pretty complex process. I'm probably better off to leave the MAF table stock, and work on the VE table for performance.
#7
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Originally Posted by racecar
I'm probably better off to leave the MAF table stock, and work on the VE table for performance.
It never made any sense to me to recalibrate a stock MAF to the mods in the engine. The only difference here is the fact that you sorta modded the MAF.
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