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
Hush kit Hush kit A hush kit is an aerodynamic device used to help reduce the noise produced by aircraft jet engines. These devices are typically installed on older turbojet and low-bypass turbofan engines, as they are much louder than later high-bypass turbofan engines. Hush kits are used because the engines on jet aircraft generate a large amount of noise, which significantly increases noise pollution near airports. The most common form of hush kit is a multi-lobe exhaust mixer. This device is fitted to the rear of the engine and mixes the jet core's exhaust gases with the surrounding air and a