well i am not agreeing or disagreeing because i dont have any analytical data however it appears that the general consensus from people is that it might
the lower the exhaust resistance and the lower the rpm the more likely the charge is to come in the open inlet and dissappear straight out the open exhaust valve, so bmep will be lower and there will be less exhaust to spool up the turbo as well
max bmep moves to higher up the rpm range, max power increases
however spool up IS faster BUT happens later, ie higher a up the rpm range it comes on boost more suddenly
this makes sense because once the overscavange effect goes away there is a higher pressure drop across the turbo
to compensate this you need to:
change the way the boost control circut works so there is no signal to the waste gate until target boost achieved
doing this the engine should reach 1.6 bar at approximately 3500 cf 4500 holding degrommeted oem solnoid open
alter the cam timing, either retarding both cams will recover lost torque but will loose boost/power at the top end
or narrow the cams, this will increase effective compression ratio raising bmep however overscavanging is made worse hence bmep gain minor and motor losses power over 4000 and has false peak at 5800 approximatey