K&N filter

[lkchris]

There was a test of BMW K motorcycles measuring airflow past filter. Compared were

Stock filter
Stock filter 1/2 blocked off
No filter
K&N

There was no measured significant difference in airflow.

Waste of money, and if you need one that's rectangular as opposed to circular, a poor quality product.

[spendy]

Originally Posted by lkchris

There was a test of BMW K motorcycles measuring airflow past filter. Compared were

Stock filter
Stock filter 1/2 blocked off
No filter
K&N

There was no measured significant difference in airflow.
.

How valid a test is this if it finds no difference in flow between a half blocked stock filter and no filter at all?

[Timco]

Originally Posted by spendy

How valid a test is this if it finds no difference in flow between a half blocked stock filter and no filter at all?

Performance based on available air?

Obviously airflow is blocked but the engine will only take in what it can unless blown. Test shows the car is "over-filtered", or it takes a severely blocked filter to actually take performance away. And more air flow doesn't always mean squat.