For those that don't already know this, the 450/510 bikes only gain about 2hp at peak with a full system and a bout twice that at about 4500rpm. If you read the propaganda supplied by Akrapovic, the claim 4.6hp at 4400rpm. They don't claim 4.6 peak hp and they would if they could. On the track you need to be above 4400 or your going backwards because that is just below the base of these things usable powerband. The stock system on these bikes is a very good setup, but the muffler is the choke point and it was designed so it can be converted to a straight thru racing can with little effort. The money spent on a full system is better spent on an ignition box, a k&n filter (oem style not a pod), headwork, cams, pistons etc. None of this applies to the 610 which is better off with a full system and I am not sure how much applies to the 08's because I have not worked with one. This comment refers to the 04-07 450/510.
