Mine was only dynoed after the installation of exhaust, air filter and the PC-V. I can't comment on the K&N filter adding horsepower or not. I like the idea of cleaning and reusing it as opposed to paying BMW for a new one every 6K miles. Thats all.
Rangers Lead the Way, Hooah!
BigDave75 screwed with this post 01-15-2013 at 07:42 PM