I recently got a K&N free flow air filter for my Honda CBR150R. The overall performance of the CBR150R has improved and I am happy with it. I also noticed that the bike sounds different while opening the throttle. How does a free flow air filter change the exhaust sound of a motorcycle?
In the regulation air filter, there are baffles that cut off the intake roar and thus restrict the wheezing sound. These baffles are not present in a K&N free-flow air filter which is why you notice the difference in the sound.