I could not yield anything with a search, however it may be a good idea to take a look at these either way.

Blitz, HKS, K&N, Apexi
http://www.mkiv.com/techarticles/filters_test/2/

Note how terrible that foam filter is. I've always hated those.


Comparing the K&N to some paper filters:

http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

Another airtest using various panel filters:

http://www.bobistheoilguy.com/airfilter/airtest3.htm


Again, sorry if this has been posted before. I know it's been around for awhile. Enjoy the reads and take each test with a grain of salt. It's not as if they were done in a lab (but foam filters are still shit ).