i got my berk HFC installed for a while now and just got a video. Its about 2 minutes long. i think it sounds pretty nice, give the stock exhaust note a deeper and louder growl. No other exhaust or engine mods, just the HFC with stock exhaust.
Rev 1 is to 4000rpm
Rev 2 is to 7000rpm
rev 3 is a quick punch to 7000rpm
and a few drive bys. enjoy and let me know what u think.