The S13a was the first really successful design that we encountered in the research project. It is derived from the design of a gun silencer,
Engine size range:
Up to 0.51 cu.in 2 stroke
Up to 0.90 cu.in 4 stroke
The original design utilised 30mm (1 1/4 in) PVC tubing, a brass front pipe, and spacers made with split segments of 30mm PVC tubing. The silencer cannot be used on 4 stroke engines in this original format, as the high exhaust temperature melts the PVC tubing. Metal versions are fine, however.
The silencer is designed to be used as a second-stage silencer, not straight from the exhaust manifold.
Although not a small silencer, I recommend this silencer if you really want to get on top of exhaust noise for 2 strokes up to 0.50 size.
We also tested a cut down version, 110mm long with only 5 baffles, referred to as S13e. This performed only slightly less well; about a decibel worse on average. |
