i've just replaced the airbox with a BBM cone intake system about a month ago. i didn't notice any noise differences from the original airbox with the snorkel removed and drilled holes.about 2 weeks ago, i replaced the silencer box with the BBM RSR kit. still, there werent much differences in sound. about a week ago, i replaced the supercharger with one i've just finished rebuilt with a 68mm pulley, then i noticed the sound is different, a bit louder, "meaner", "purrrrrrrrrrrr" @ idle. when i gas it, the purring turn into a freaking awesome rawr, and i just love it!!!