Header bottle?

[Nahum]

Don´t know how to call it but it seems as if this "header-thing" becomes more and more a "must have" add-on.

What I want to know is:

Is it just as simple to drill a hole an weld any kind of "bottle" on my header?

Do I need a special sort of material? Whats the secret behind? Do I need a special formula to calculate the volume of that "bottle"?



http://img7.imageshack.us/img7/5701/dsc004237563618.jpg

http://www.ews-wig.de/Meine_Bilder_und_Dateien/x_quad-db-absorber.jpg

[CSR400EX]

from what i have read, all it does is lower the db output of the exhaust.

[Nahum]

lower the db output

Yeah ok, it lowers the db output without loosing hp but ... can I make such a bottle of my own? Will any size work?

It needs to be so far from the head and the hole has to be so big for it to work right. i have them on my bikes (450r) and they crack and break off all the time. if you dont need it than leave it alone.

[GPracer2500]

Search the web (or library) for Helmholtz resonator.