looking for a legal Db silencer

[300exQuadracer]

who makes a pipe that will meet the db limit of 102?? it says in the rule books everyone will be checked. any info would be appreciated

[wilkin250r]

Indeed. I've seen quiet pipes for 4-strokes, but I don't think I've seen any for 2-strokes. Anybody have information?

[D Bergstrom]

Originally posted by wilkin250r
Indeed. I've seen quiet pipes for 4-strokes, but I don't think I've seen any for 2-strokes. Anybody have information?

The only quiet silencer for a two stroke I have seen is the FMF Q. I have one on my CR500, and to be honest with you, I do not think it is all that quiet, but I do not have anything other then stock to compare it to.

Doug

[300exQuadracer]

i dont want to get to the races and not pass inspection for being too loud
maybe its just for 4 strokes but i took it as for all bikes

[Jester]

FMF q is quieter at idle.. compared to a turbine core.

[Rich250RRacer]

I never thought I'd see a thread like this. When I went through tech inspection at one of the GNCC's with my 250R, they were checking sound level, but they didn't even attempt to check me. I asked them why and they said "it's a 2-stroke, you'll pass". Just for the hell of it, I told them to do it anyway. They were right, 89db :D

[300exQuadracer]

what silencer where you running,
i guess you can hear by ear if a 4 stroke is too loud or close, but i allways thought a 2 stroke was almost as loud

[Rich250RRacer]

Originally posted by 300exQuadracer
what silencer where you running,
i guess you can hear by ear if a 4 stroke is too loud or close, but i allways thought a 2 stroke was almost as loud

FMF. I wouldn't have believed it if they didn't show me the meter. I know nothing about the dynamics of sound, but it seems to me like the deep sound from a 4-stroke carries much farther than the sound from a 2-stroke.

[BLACKeR]

the 2-strokes arnt near as loud as the thumpers you can probly run whatever silencer you want.

[250r4life]

i always thought my bike was super loud, but i guess its not as loud as i thought... my buddy has on 06 yfz 450 with an HMF pipe, and he and i have a good little rivalry going and we shoot the hill at the dunes over and over again. i just repacked my silencer a month ago, as it was completely blown. so, even with a blown silencer, everybody else in my group said that when we race, that can't even hear my bike and that all they hear is my buddies yfz

[wilkin250r]

The human ear response is a little more keen at the frequencies that 2-strokes put out. So, while standing next to one, a 90dB two-stroke sounds as loud as a 100dB 4-stroke, because your ear is more sensitive to that sound.

However, as Rich already pointed out, the lower tone of a 4-stroke not only carries further, it also generally has more power behind it. That's why you can usually hear the 4-stroke rumble over a 2-stroke at a distance, and why 4-strokes have problems meeting sound-level restrictions.

[300exQuadracer]

ok that answers all my questions and may help some others out too