surely under heavy boost a few problems might crop up....ie...if the bov isnt tuned correctly, its not going to be a fan of air/shockwave whizzing past it the wrong way on gear change lol, or even air flow stalling yet the pressure in the pipes still being substantially higher than atmospheric. open the throttle that air will enter the cylinders but would the maf essentially pick up how much enters causing it to run lean for a second.....,red reading said:nex the mass air flow sensor does just as it says,it does not sense pressure,it senses flow,where you put it on the induction side shouldnt make any differance as the amount of air going thru it will be the same under pressure or not,and samgtr have you just changed the turbo from say a t28 to a 3071 if you have then yes it will need mapping
also if the pipes aren't downsized, and its just put into a bigger pipe as suggested in the first post, air flow speed will be reduced and the maf will give an incorrect reading i'd have thought?
just my thoughts, prob wrong though lol