Exhaust reducers in stainless or mild steel.Models with three diameters can be cut to fit a pipe with the middle diameter as well.An exhaust pipe reducer allows a diameter change with minimal flow restrictions.
Vacuum exhaust valves allow mild sounds while streeting, and roaring exhaust sounds on the track.A valve can open and close the exhaust flow. Examples of use are a screamer pipe directly after the downpipe, or a muffler bypass.