There were a couple revisions made to the new pipes. There were 2 original prototypes built 6 years ago which had 3 step headers compared to 2 steps on the new version and the megaphone is a 1/2" larger entering the canister on the production model. The new exhaust with the revision to the header is more accommodating to smaller and medium builds with the ability to maintain flame travel in a broader range of motors.
The explosion that occurs in the cylinder during combustion is processed through the exhaust valves and into the header as a actual flame. To define flame travel to those that don't know, it is the exhaust gases exiting the head, the hotter the gas (flame) the faster it travels through the header, maintaining this flame is key. The flame can be extinguished or prolonged based on the size of the header in relationship to the build size. Flame travel is key in maintaining power, if the flame cools too quickly while traveling through the header substantial power loss will occur. The prototype 3 step headers were targeted towards 575+cc motors which require more air flow through the header and can maintain flame travel longer with increased header diameters. These larger diameters can be an advantage in big cc motors as long as the steps are positioned correctly. The production exhaust have an advantage over the original prototypes in that they will work with a broader range of builds, maintain the flame travel longer, while releasing into a larger megaphone which is where the power advantages are produced over the competition.
when gary and i were testing his 70HP TRX years back... the best pipe setup was one of the Venom Super Short / stepped anti reversion headpipes.... coupled with a sparks megaphone section made for the yfz450...
For clarification before this thread goes to heck. There are different types of flame travel when discussing tech, notably combustion flame travel. My reference was to exhaust flame travel and how header diameters can dictate power.