So I am trying to back into how the PCM is calculating torque and airflow, I see how HP Tuners laid it out in the formulas, but the math is simply not working.
Here is the math...
Airflow (g/sec) = (commanded torque (Nm) - Torque/Airflow Offset (Nm))/Torque/Airflow Factor (Nm/g/sec)
When you divide the NM of torque by the factor, NM units cancel out and youre just left with g/sec...
I have been logging the following channels:
Powertrain Thottle TqReq - matches exactly to the table found in Engine>Torque Management>Auto Trans TqMgt, this is essentially your COMMANDED TORQUE for all intensive purposes
Trans Engine Torque - appears to be your CALCULATED TORQUE
So here is just one exact spot...
900RPMS in gear at a stop
Powertrain Thottle TqReq: 48Nm
Trans Engine Torque: 101Nm
Total Airflow: 19.2g/sec
ECT: 181*F
MAP: 68.4 kPa
At 900RPMS, my tune has the following parameters:
Torque/Airflow Offset: -14.84 Nm
Torque/Airflow Factor: 11.75875 Nm/g/sec
Friction Torque Loss: 39.5 Nm
Flywheel Req. Tq - DR: 52 Nm
So first off, a bit of a rounding issue but the Flywheel Req. Tq - DR is essentially equal to the Powertrain Throttle TqReq, which is what I expect...
Now the Trans Engine Torque I am guessing is ACTUAL flywheel torque, either that or it is POST torque convertor torque multiplication, would would make some sense as most are around 2x multiple. But I see it move around a TON more than the torque commanded, and in fact when in park/neutral the commanded torque goes to zero but yet the trans engine torque remains populated, telling me its actual torque calculated.
So now when I attempt to do the airflow calc using either one I don't get even close:
Using Powertrain Throttle Torque: (52Nm - (-14.84Nm))/11.75875 Nm/g/sec = 5.68 g/sec
Compare to my logged total airflow of 19.2 g/sec Not even close
Ok so I thought maybe total airflow is calculated on actual torque calculated, could make more sense, here is that calc:
Using Trans Engine Torque: (101Nm - (-14.84Nm))/11.75875 Nm/g/sec = 9.85 g/sec
Still confused...anyone have any insight?