Typically these systems uses the MAP, rail and boost sensors to fool the ECM in thinking it's lower that it actually is. In return the ECM increases the fuel pressure to the injectors for a higher flow rate to compensate for the lower sensor readings. These setups work fairly well to a point. There are limits due to the maximum output for the high pressure pump, injector flow rate and the turbo's efficiency map. Last thing you would want is having the system fuel mixture lean out, and cook the turbos from high drive pressure, both would be bad news.