Dirt Rider got a sneak peek at FMF’s new Q4 while out testing some KTM EXCs last week and we wanted to show the company’s latest quiet muffler to you. The insides are still a bit of a secret but we do know they are using a chamber design, similar to the Powercore 4 to further reduce the sound without disrupting the flow. Additionally the new canister, an extruded aluminum body, holds more packing for less sound and longer packing life. Obvious detail changes are to the end cap and to the machined mounts which look a lot more technical.
As expected the noise output is definitely toned down compared to the older Q4, especially at running and sound testing RPMs. You can really hear the difference yet the muffler still allows a good sound, especially to the rider where the crack of the throttle or the snapping noise is pronounced. On the bike you hear a snap but to someone off the bike it is not noticeable. And compared to a Powercore 4 the Q is definitely much quieter. The good thing is that the power is minimally affected, especially considering the reduction in sound. The unit we were riding with (on three different bikes, 2012 500 EXC, 2012 350 EXC and 2008 530 EXC) didn’t lose any throttle response or snap compared to stock or the older Q and in fact seemed to pick up a little there. Then the muffler promotes a very linear or progressive build of power and the FMF guys think they could get even more out of it here with minor tuning, hence why we were riding it. Funny thing was that it really picked up on the carbureted bike compared to the FI machines, typically jetting is required when a restrictive or quieter muffler is installed so this thing must flow.
Expected to be available for most late model bikes in a couple of months it is really positive to see a company so committed to keeping the sound down without sacrificing anything in the power. Actually gaining some along the way.