Stock MAF or aftermarket? If makes a big difference as an aftermarket unit such as a Pro-M will show lower numbers.
Why you ask?
Because the aftermarket unit will flow a larger amount of air for the same specific voltage as a stock unit. Since you are still using the stock MAF Transfer Function the computer will think you are flowing less air and this in turn leans out the A/F mixture. (I.E. power gain)
Now if you could reprogram the PCM with the appropriate MAF Transfer Function (derived from the MAF flow data supplied with every Pro-M MAF) you would be getting somehwere.
I haven't checked in a while (a year), but with the Pro-M I have peaked in the 21 range. I figure a little higher now (22's probably).
I can tell you on the S-AFC I get in the 36% range. (I see that daily)
I'm sure my exhaust is holding me back a bit. Soon to be remedied...
