How to calibrate map sensor with no negative offset number possibility ?

[gt35]

i have a new VEMS round i am trying to calibrate the MAP sensor signal to instead of showing the ADC value to show boost PSI.

For the calibration i can set the calibration scale and offset, but i cannot put a negative offset value hence i cannot make it work as the map sensor start at Negative pressure.  How do i make the display gauges to show the correct value ?

I have also played with the input calibration table, but i cannot make that work either again i cannot make zero PSI equal zero without a negative offset value.

[gunni]

It seems the scaling doesn´t allow negative values at all. So you are forced to use absolute pressure readings, is that a problem for you?