Sensor signal out logging
Have you read the service manual?  Is your concept valid for the sensor interface?

(just a long comment)

Bosch Sensors have a thermal offset
Temperature coefficient offset
(+25°…+40°C @900hPa)    1.5 Pa/K, equiv. to 12.6 cm/K


  Thus as the engine warms up you may see a hystereis noising effect of your linear data, so there is no correlation when all lumped together


e.g. BMW, VW 97

When the intake manifold pressure is low (high
vacuum) sensor voltage output is 0.25-1.8 volts at the
ECM.       
  When the intake manifold pressure is high due
to turbo boost, the sensor voltage output is 2.0-4.7 volts.      
  The sensor receives a 5-volt reference from the
ECM.    
  Sensor ground is also provided by the ECM.   
The ECM uses boost pressure combined with the intake
air temperature to determine the volume of air entering the engine  

DIAGNOSIS AND TESTING - BOOST PRESSURE SENSOR     
If the boost pressure sensor fails, the ECM records
a DTC into memory and continues to operate the
engine in one of the three limp-in modes.      
  When the ECM is operating in this mode, a loss of power will
be present, as if the turbocharger was not operating.      
The best method for diagnosing faults with the boost
pressure sensor is with the DRB III scan tool.