Your B205R engine is controlled by a T7 ECU. This version of Trionic requests airmass per combustion, not boostpressure like the older T5 does. To achieve the airmass needed, the ECU adjusts boostpressure and throttle setting. Increasing boost will only result in higher intake air temperatures. The turbo will produce more heat since it's working harder and the trottle will close a little to compensate for the increased boost.
The only way to get more power will be an ECU remap, as Mark A already suggested.