How do I retrieve the calculated AIR FLOW values from the stock computer on an Acura RSX-S. I need the AIR FLOW not the air/fuel ratio. The vehicle computer calculates this using values for MAP pressure, temp., etc.. AIR FLOW as in CFM or gm/sec. etc.. Please help

 

does anyone know anything about this?

 

Thi is not something that is easy to do. You would have to connect to the ECU, and then go to wherever it stores the airflow and record it.

That is how OBDI/OBDII datalogging systems work, but they take a huge amount of development to make work. If one isn't already avaliable for you, you're out of luck.

 

Since nobody else has something... I wonder if maybe it's even harder than that.

The ECU might not actually calculate air flow explicitly. If it fires the injector once for each intake stroke (for each cylinder), then maybe all it really calculates is air density based on manifold temperature & pressure.

 

For my computer, fueling and ignition are based on MAP and engine rpm. There's a lookup table that it used. CFM doesn't enter into the equation AFAIK. This is a chipped P28, BTW.

When people say airflow is inferred, I take that to mean that airflow has been inferred by the Honda engineers that wrote the fueling tables. Nowhere in the tables does it list airflow.

 

The computer probably does not explicitly list airflow, but it does have to have a correction table for pressure and temperature. If you could pull all these numbers, you could figure it out, but it would not be easy to do.

 

Nor would there be much point! It would be much easier to measure the results directly rather than pull the info from the computer.