Expansion chamber

A resonant exhaust is an exhaust system of internal combustion engines, which is mainly used to optimize performance in two-cycle engines. In the MZ racing department Walter Kaaden dealt with it. He found that the use of resonance waves in the exhaust tract leads to a substantial increase in performance and developed the resonance exhaust, comes in the racing and model as well as in road vehicles.

This exhaust is basically composed of six parts: the manifold, a usually bent pipe with constant diameter, which is connected to the outlet of the cylinder, an opening cone ( the so-called diffuser ), a cylindrical center piece, a closable countercone ( reflector), the pressure tube, a tube of constant diameter and of specific length, in which the last part of the exhaust pipe resonance, connects the silencer.

Its basic function is the exhaust gas pressure wave, suck ( the so-called "puff ") which expresses the exhaust upon opening of the outlet, and to reflect a part of the pressure wave at the counter-cone. Through the diffuser is formed between the cylinder and the beginning of the cone, a negative pressure gradient at the outlet of which a suction effect which conveys the exhaust gas from the cylinder. Of the trailing counter cone reflected portion of the shaft passes again through the entire exhaust back to the outlet and pushes possibly with addition carried in the exhaust fresh gas back into the cylinder, whereby the cylinder is again " recharged " and from the outlet side with the mixture. You can reach so that in the best case ( when reaching the so-called resonance speed ) optimal cylinder filling ( see animation below ).