OneBad98Z

iTrader: (1)

ive been logging my maf hz and dyn airflow and using automafv25 to calculate a new maf table, my question is my numbers are like 10% higher or so, than a stock maf with screen, mine just a stocker without a screen is it normal for the calculated numbers to be this much higher after descreening? or am i doing ssomething wrong the scatter chart looks similar to a monaro maf table.

Thanks, for all the excellent help with the tuning guys

Greg

TAQuickness

iTrader: (28)

I haven't actually measured the airflow, but I did notice my actual ARF's were about 1% higher (leaner) after I removed my MAF

jimmyblue

iTrader: (11)

Odds are you are not strictly MAF limited but more
pumping limited, there is a small BARO-MAP drop
and overall I would expect this is where you would
see the difference most clearly. Consider it a nearly
constant flow before/after, look at BARO-MAP and
you should see the before & after curves diverge at
higher RPM.

Figure at lower flows the frequency shift is more
likely airflow bias, metering error than airflow increase.
If it's 10% across the board that just isn't from the
airflow increasing. I bet below 5000RPM, your
(BARO-MAP)/BARO doesn't have 10% left to give.

But then it's been a long time since I had a screened
MAF, and maybe it's worse than I remember.

StealthV

10% higher isn't unreasonable; as I've had similar results and the MAF is dialed in perfectly. Think of it this way, without the screen, the MAF has a harder time measuring air rushing past it. Since the MAF is "seeing" less air, the MAF table has to be higher to account for it. You're on the right track. Make the MAF tweaks and do some more logging...