After conducting the flow test of the stock BMW turbo inlet pipes I was contacted by MM Performance Engineering with interest in seeing how their aftermarket inlet pipes compared with the stock pipes.

Shortly thereafter a set of the MMPE inlet pipes arrived and I tested them out on the flow bench.  Results below show the MMPE pipes compared to the BMW stock inlet pipes.

The aftermarket pipes show a substantial improvement in airflow at the test points when compared with the stock inlet pipes.