Yeah i have no idea and im not really that worried, it goes fast it runs smooth and im happy. Unsure on the issues behind lack of power or torque or whatever it is you say thats lacking. Maybe ill try a different tuner next time. I dont see why 850s would max out either but thats what was said to me. If i knew more about tuning id be able to answer. It is a smallish turbo so once i change it ill see what power i get. My brother can have a look on his laptop at the tune as hes a guru on that stuff and can see what everythings doing, or anyone else that wants to is more than welcome to have a gander