Subaru Airbox MAF Flow testing

A Subaru owner contacted me about putting their airbox on the flowbench to determine how closely the Subaru table for MAF voltages matched with real airflow.

Subaru Airbox on Flowbench
Subaru Airbox on Flowbench

I ran this experiment with the S4 MAF Sensor and did not get a very good match so I was interested to see how things would turn out with the Subaru setup.

Subaru MAF Voltage Table
Subaru MAF Voltage Table

Because the voltage from the MAF sensor is not read by the hardware for measuring the flow bench airflow and pressure drop I needed to hook up a multimeter to the MAF sensor 5V output wire and take manual readings at various airflows.  Although this method is not a precise as it would be if all sensor values were read by the same datalogger, the results were good.

Flow Test Results vs Subaru Table
Flow Test Results vs Subaru Table

Agreement between the Subaru MAF table values and the measurements taken on the flow bench were good.

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