I swapped the turbos on my TT GTO (2006, E40 ECM) for a set of GT3071s, and in the process I switched back to an older MAF tuned map to get a starting point. This map has the dynamic airflow disabled, so the car is running on MAF only. (It is a SD OS Map however, with a 2.5 bar map sensor). MAF is the stock 06 GTO MAF, and above 5400RPM the MAF is pegged.
I did a small 3rd gear pull to 5700rpm at wastegate boost (7psi).
Pull Datalog below:
In the center graph, yellow is the VE Airflow and cyan is the MAF Airflow. I was puzzeled by the jump in the yellow line early in the pull.
You can see the data right before the jump:
Then the next cell over after the jump:
Before the jump, the VE Airflow is 11.81, and after the jump it is 25.36. The MAF Airflow is around 26.39 at this time. This switch occurs right at 3000 rpm, and I am trying to figure out what the cause is. Looking at the dynamic airflow page in HPT, there are the boundaries for the dynamic zones that corresponds with 3000 RPM. Based on the MAP before and after, the dynamic airflow zone would change from 13 to 17 at 3000 RPM. It is my understanding that these "Dynamic Zones" alter the calculation method for the VE/MAF blending. Does anyone know if the Dynamic Zones would/could correspond to such a significant change?
Dynamic Zone Config (2006 GTO E40)
I also noticed that at the point before the jump the "Dynamic Airflow" is 23.88, while the "Mass Air Flow" was 24.81. Right after the jump the "Dynamic Airflow" was exactly the same as the "VE Airflow" and follows each other exactly for the rest of the pull.
(Data mentioned above)
I suppose all of this does lead to the question about what is the difference between "VE Airflow" and "Dynamic Airflow".
Is the "Dynamic Airflow" what fueling would be based on if we were in VE/SD mode, and is the "VE Airflow" what the algorithm would use for the dual combined Dynamic/MAF calculation?
Jeff