Hello,
its a known issue for a long time which seems that nobody can solve.
On the MED17.1.1 of Audi RS3 2.5TFSI 367HP 2015.
All over 1,55Bar the throttle closes and so not more boost is possible.
Anybody knows how to overcome this ? Of course not for free ...
Better off joining a winols of chiptuning group on facebook and asking. Clearly your not going to get the answer here.