http://ecomodder.com/forum/showthrea...aust-9429.html
This thread along with the comments of air flow have me really thinking...
FMF makes headers which may require second thought for motorcycles with mini "2 stroke style" chambers.
FMF: "The redesigned PowerBomb is a four-stroke header that incorporates FMF’s patented PowerBomb module at a precise location in the initial stage of the header.
By positioning this “Bomb” at a key point in the system, increased performance and flow is achieved through the expansion and contraction of exhaust sonics through the system. Result is a flow increase of nearly 10%! The outer chamber in the Powerbomb allows the air to expand, cool and ramp back up at a higher velocity. Additionally, the PowerBomb is a “pre-muffler” of sorts which helps to lower the bikes sound output by providing more sound absorbing surface area for the sound medium (exhaust gases). On some models, you can choose between a moto or supercross version. The supercross version is designed for
more low to mid-range power where the moto version is focused in the mid to upper RPM range."
So is the goal of fuel efficiency less turbulant exhaust air? Or more smoother flow?