Engine 1.9 tdi 130 awx stock

hi everyone, I'm new to the forum.
I have a little question that I can not clarify. I have to say that unfortunately I do not have updated software to work on the rimappe. so I'm happy of what passes the convent.
then the first question is the main injection, the one that ecm calls injection zoned. from what I know, the cars ori have a stoichiometric ratio that varies from 17 to 20 parts of air to 1 of fuel (index AFR). quimdi going to touch these values, it increases the injection of diesel fuel and will increase the performance of the engine. for example, in the last bp of the column 100... to calculate the air mass, equal to 1000 then if we have a value of 7500 in edc15p correspond to 75mm3, and doing the calculation 75 x 0.835 = 62.62 mg diesel ; 1000 : 62.62 = 15.96 ratio AFR then a little bassino and the machine should sfumacchiare a bit. but the doubt is mine, in all this, the turbine pressure, what is the role? that is, if we raise, what happens to this ratio AFR? what is the role of the pressure turbine on the calculation of iq based on the airflow? I do not understand..
for now, this doubt haunts me. when I clarified, we will move on to the next!
grazieeee

Hello!surely c is the one who can explain it better than me..from engine ori try to do a log to see the mg of the intake air then you raise the turbo pressure of for example 100 points and redo a log and see the difference..according to the intake air and the fuel injected calculations l afr the more air you have the more fuel you can put