FMF Q Anyone Have One?

I just bought a leftover YZ450F and it is quite a bit louder than the stock 426 it replaced. Does the FMF Q make the bike much quieter and what, if any, changes does it make to the overall power? Any comments would be great.

We have an FMF Q on the 2001 426. It makes the bike very quiet. I don't use all of the power, so I don't know how much it changed, but the bike is still very powerful. Dyno runs I've seen place the Q as putting out decent horsepower. You're not going to use the extra 1 hp from a louder pipe, so you might as well get the Q.

I just bought a leftover YZ450F and it is quite a bit louder than the stock 426 it replaced. Does the FMF Q make the bike much quieter and what, if any, changes does it make to the overall power? Any comments would be great.

Got one on an 02 yzf426.Its a lot quieter,but it seemed to be less responsive,even after jetting.Still not bad,i like QUIET.

I have one on my bike sometimes.

It's pretty good at muffling the bark above mid-rpm, but it's far from whisper-quiet like a corked-up street bike.

A newly repacked stock YZF is actually pretty good, but once the rpm's rise and the main exhaust pulse pushes out behind the long muffler, you could just as well have a straight pipe. Riding it at low to mid rpm could be similar to the Q.

The Q has the extra chamber that traps and jumbles the exhaust pulse and forces the excess force into the packing, while keeping a decent sized exit hole to vent out the total volume of gases.

Many after-market "performance" pipes are more free-flowing and a lot louder.

Putting on a Q often requires rejetting to a smaller pilot and main jet.

A Q is pretty cheap, but new packing is even cheaper.

Definitely takes away the "bark". I have one on my 04 450. Very happy with it. Power wise I don't think there was very much performance loss of the stock pipe (if any). But the bike has too much power as it is, so I don't think I would notice anyway. I wouldn't say it makes the bike quiet by any means, but alot quieter then stock. Hope this helps a little.

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