I recently got a "banana" expansion chamber from ebay for $35. It doesnt have the silencer on it. Anyways its pretty quiet in my opinion, but the sound that does come out is very rich. The second i start up my bike it now pulls like all ****. Big difference from the stock exhaust! Remember these dont improve top end (maybe 1-3mph) just acceleration. I hit 34 mph with a 44t sprocket today weighing 175 lbs 6ft tall and it now pulls up hills like nothing. Enjoy