Yes a lot of limitations!
but in the case are the guidelines for the date of the first approval,
which was the year 1995, which is decibel limitation in this year ck 98 db! + - 2 db. ;-).
I've already something built for a Fat Boy silencers. the Silencer comes from a 60hp Opel city.
the silencers has a larger diameter than the Fat Boy. the output product of the engine is no obvious advantage.
and the mix becomes richer. C.K. 85 db like this ...

Where can i get a DCS 6 and the Price ?