Description And Operation
The exhaust pipes coming from the engine enter the muffler, under normal conditions the exhaust is exchanged in the muffler and will exit out the opposite tail pipe. This action is achieved by adding by-pass throttle valves in the tail pipe that will be normally closed. In a performance condition, the by-pass throttle valves open and allow the exhaust to flow straight out the tail pipe.
- 1 - Exhaust pipe coming from the engine
- 2 - Right exhaust pipe coming out of the muffle
- 3 - Left exhaust pipe coming out of the muffler
- 4 - Inner bulkhead limiting the muffler chambers
The figure shows that the muffler is subdivided internally into 6 chambers limited by 7 bulkheads.
When the by-pass throttle valves are closed under normal conditions, the exhaust gases follow the flow through the muffler as shown in illustration.
The gases from the engine bump against the by-pass throttle valves and unable to flow out the tail pipe, find an outlet through the machined hole on the pipe within the muffle connected to chamber (1), and through the small machined holes of the preceding chamber pipe (2). The exhaust gases escaping from the small holes expand inside chamber (2) dampening the pressure impulses. The gases that fill the chamber (1) exit out through the opposite tail pipe (in red). This allows the pressure impulses to be dampened in chambers (1) and (2) at the same time and limit the exhaust noise
When the by-pass throttle valves are open, the exhaust gases follow the flow through the muffler as shown in illustration.
With the by-pass throttle valves open, the exhaust gases from the engine flow freely out the tail pipe. The straight flow of the exhaust without dampening generates more external exhaust noise.