I've heard that rather than buying the whole K&N filter assembly, you can simply drill a larger hole under the air filter itself or cut out portion of the air box assembly so the engine can pull more air compared to the tiny hose/hole it currently has. Sure you can even install a K&N or any other reusable flat filter that lets it breathe better.
Has anyone done anything similar?
Similar to what this guys is doing:
Has anyone done anything similar?
Similar to what this guys is doing: