Yamaha YFZ450

[dfinocchio]

Does anyone have any information they would like to share regarding mufflers used for the Yamaha YFZ450 (or similar) motor? We have looked at the yoshimura pipes, but are considering fabricating our on muffler. I've heard of troubles passing the noise test with the Yoshi pipe used for this motor.

[dfinocchio]

Does anyone have any information they would like to share regarding mufflers used for the Yamaha YFZ450 (or similar) motor? We have looked at the yoshimura pipes, but are considering fabricating our on muffler. I've heard of troubles passing the noise test with the Yoshi pipe used for this motor.

[LU-Hetrick]

We used a yoshi pipe last year and had a lot of trouble passing sound. Ended up taking it apart stuffing it with different packing and using the factory spark arrester. Without the arrester we were bouncing between 110 and 111 dB and they wouldn't pass us. With it we dropped to 106. In the autocross some of the packing worked its way out of the muffler and clogged the arrester. We are making our own muffler this year.

Ryan Hetrick
Lehigh University FSAE
Brake, Suspension, Chassis

[Jose]

We are using a FMF Q/2. with our 450 and it gets up to 116 dB. So we are working in some modifications.

[Chris Allbee]

If you use a coarse steel wool to loosely wrap the perforated core before packing with fiberglass it will help prevent the glass from burning out and clogging your spark arrestor. It may also have the side effect of increasing the noise by 1-2dBs.

[Wesley]

And if you can find it and care about how long that particular muffler lasts, stainless steel wool will deteriorate a bit less over time. It's just hard to find.