| 摘要 |
An asymmetric exhaust system comprises one exhaust pipe per cylinder. Where the motorcycle engine has two cylinders in a V arrangement, the second exhaust pipe joins the first exhaust pipe downstream of a reflective feature 16. This feature is an enlargement 16 of the first pipe's cross-section. When an exhaust valve opens, a compression wave travels towards this feature, which produces a reflective negative wave which travels back towards the valve to assist the removal of gases from the cylinder. The difference in pipe diameters at the junction 18 of the two pipes also acts as a reflective feature. The value for the length of each pipe 11,13 which is upstream of the relevant reflective feature 18,16 is designed to maximise the efficiency benefits from increased gas removal and improved cylinder charging. The system includes at least one silencer 22 and exit pipe 23. |
