BMW 335i N54 Inlet Pipe Test

Something different from what I’m normally testing, a BMW part.  Inlet pipes for the BMW E92 335i N54 3.0L engine.

BMW E92 335i N54 3.0L Inlet Pipe
Pipe 1
BMW E92 335i N54 3.0L Inlet Pipe
Pipe 2

The results:

BMW Inlet Pipe Airflow E92 335i N54 3.0L
BMW Inlet Pipe Airflow

For those wondering, at 28″ the higher flowing pipe has approximately 44% more CFM passing through it for the same pressure drop.  A good example of how subtle design differences can greatly affect airflow.

Some additional photos comparing the two pipes and their shapes.


bmw_pipes-a bmw_pipes-c bmw_pipes-d

Adding a chart with extrapolated pressure drop information out to 350 CFM based off a least squares fit to the measured system data.

BMW N54 engine inlet airflowAnd some additional airflow testing of a pair of aftermarket options, one from MMP and the other VTT.