The stock MAF is only "calibrated" to work up to 4.7852 volts (~775 kg/hr or only ~375-380cfm!)
Yes it will read higher (820 kg/hr (~400cfm) max at 5 volts) but the PCM will not recognize it properly.
3L at 5600rpm & .5 bar
That equates to roughly 265cfm ^ .5bar = ~375cfm
2.5L at 6300rpm (turbo's HP peak) & .68 bar
232cfm ^ .68 bar = ~390cfm
Both would correlate pretty well to the limit of the stock MAF.
