Aftermarket exhaust parts and the engine. However, the pipes do "ring" with the exhaust pulses and increase underhood noise. Headers can be ceramic coated to reduce the heat radiated in the engine compartment, and to increase the temperature of the pipes which increases the velocity of the exhaust gases. Terminology: Catalytic converters are necessary to reduce emissions but create back pressure due to the exhaust gases being forced through a catalyst, and therefore decrease high-end engine power. Many modern catalytic converters only produce 1-3 psi of back pressure, though this restriction worsens further with use. Hi-flow catalytic converters can replace the standard units
Steam locomotive exhaust system reason the blower is often turned on in these situations, to counteract the compression effect. The aim of exhaust system development is to obtain maximum smokebox vacuum with minimum back pressure on the pistons. Little development of the basic principles of smokebox design took place until 1908, when the first comprehensive examination of steam-raising performance was carried out by W.F.M. Goss of Purdue University. These principles were adopted on the Great Western Railway by Churchward. Andre Chapelon made a significant improvement with his Kylchap exhaust which incorporated a "Kyala spreader" (second stage nozzle) and third stage cowl between the blastpipe