All stopped up

[CB4ME_imp]

On a recent thread about an SP Tadao power box exhaust, the question was asked just exactly what the power box does.



There was speculation but no definitive answer.

The thread also included a link to a mechanical stopper at McMaster-Carr for anyone wishing to pull off the box.

Here's what it looks like installed:



I think removing the power box is an improvement. The tinny sound is gone, the exhaust sounds deeper and it has more bark. Even better than the Staintune.

A lot of manufacturers engage in a bit of marketing hype to distinguish themselves from the competition, and I think this may be the case here.

[the Ferret]

so, if you are not going to use the box, but stay with the stopper, couldn't you shorten the stub a bunch?

[dr_rock_imp]

Interesting concept and that exhaust looks really nice on your bike.

[INTP_imp]

Is it a helmholtz resonator?

https://en.m.wikipedia.org/wiki/Helmholtz_resonance

[CB4ME_imp]

Is it a helmholtz resonator?

https://en.m.wikipedia.org/wiki/Helmholtz_resonance

Interesting. From the Wikipedia entry:

"The theory of Helmholtz resonators is used in motorcycle and car exhausts to alter the sound of the exhaust note and for differences in power delivery by adding chambers to the exhaust. Exhaust resonators are also used to reduce potentially loud and obnoxious engine noise where the dimensions are calculated so that the waves reflected by the resonator help cancel out certain frequencies of sound in the exhaust."

Without the power box, the sound is less symphonic but more bad a$$.