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
Exhaust heat recovery system Chinese regulation, more and more stringent concerning CO2 emissions, exhaust heat recovery sounds like one of the most efficient ways to recover a free energy, since heat is generated in many ways by the engine. Numerous companies develop system based upon a Rankine Cycle: The German company has been one of the first major to study exhaust heat recovery with a Rankine system called Turbosteamer. Honda also develops a module based on a Rankine Cycle to improve overall efficiency of hybrid vehicles, by recovering the heat of the engine and turning it into electricity for the battery pack. In the