Best way in tuning fuel on WOT

Guys i am using a M600 Motec ECU and i dont have the data logging option enabled so i would like to know the best way and the most efficent way on tuning the fuel on a WOT

Thanks

You need to have a datalogger of some sort that can plot RPM Vs your AFR. Dyno facility would be best but you could also use the likes of an Innovate LM2 with the accessories which allows RPM logging