Dynos & AFRs
 

In looking at few stock dynos the AFRs are in the 10-low 11s range. On my stock G37S when I data logged my AFRs they topped out at 12.28.

Any idea why the huge difference? I would of thought the stock target AFR would be the same and around 12.2 for "safe best power"

Could be that Nissan is trying to squeeze every MPG out of these cars. When I had mine dynoed a few years ago (CBE, HFC and Cold Air Intake) mine was in the 12.25 - 13 range, even at wide open throttle with the stock tune.

Most guys are running 10-11 AFR when TT and pushing for power...

That range is what I would expect for a stock tune. The stock target AFR does not change with bolt on mods.

I am trying to understand how some stock tunes show up between 10-11 AFR. The only thing I can think of is the wideband O2 used to sniff the exhaust is old or not accurate.

FordMuscle Mag did a comparision test and found HALF of the eight wideband sensors tested were out by 1.5-2 points!!!
http://www.diyautotune.com/downloads...20Shootout.pdf