FMF Full Exhaust Powercore 4 and Power Bomb-2009-20013 Yamaha YFZ450R/X
We developed the PowerCore4 to increase the horsepower and torque throughout the entire power curve producing a noticeable power increase that is useable and compatible with every style of riding. Aluminum construction and stainless steel Hi-Flo endcaps make for the perfect balance of performance and strength.
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).