What It Is
With an all-new YZ450F for 2010, many exhaust companies scrambled to make an exhaust system that both produces noticeable power gains and fits into the small, confined area allotted for the YZF's new "tornado style" header. The reversed exhaust design also made it difficult to incorporate FMF's signature MegaBomb header. To combat this, an entirely new MegaBomb was designed to attain the same effect and power increase as the traditional MegaBomb header. The entire system is made from titanium and designed to mount right up to the all-new YZF.
Installing the system is a breeze, as it mounts up seamlessly without any snags or wrestling to get it to fit. With the new system mounted up, the power increase was excellent. In stock trim, the YZ450F has tons of low- to mid-power but falls off and doesn't rev out up on top. With the FMF system installed, the YZF revved out much further, pulling each gear longer and farther. Down low, the power didn't suffer, and in fact, actually benefitted from the exhaust system, adding a small amount of pull while not gaining so much power that it was uncontrollable.
It hasn't affected anything, but the MegaBomb header sits very close to the shock, begging the question as to whether or not the heat will hinder the shock performance in a long moto.
I've been riding the new YZF a lot lately, and have come to really want more top-end out of the bike. The new FMF system answers my demands with a healthy top-end gain while still adding slightly to the low-end grunt. I'm pleased with the power and would likely recommend this system to anyone.