Straight Through Muffler

The straight through muffler has a central tube, perforated with several openings which lead into an outside chamber packed with a sound absorbing (or insulating) material. As the exhaust gases expand from the perforated inner pipe into the outer chamber, they come in contact with the insulator and escape to the atmosphere under constant pressure. Because of this, the expanding chamber tends to equalize or spread the pressure peaks throughout the exhaust from each individual cylinder of the engine. A V-8 engine requires two exhaust manifolds and either one or two mufflers and often accompanying resonators. If one muffler is used, the exhaust pipe from one manifold meets the other one in the form of a "Y".