Intercooled

Intercooled is an adjective used to describe equipment or systems that employ an intercooler to cool the air after compression in a turbocharged or supercharged engine. The primary purpose is to reduce the temperature of the charge air before it enters the combustion chamber, increasing air density and allowing for more efficient combustion.

A typical setup routes compressed air from the turbocharger or supercharger through an intercooler, which transfers heat to ambient air or to a cooling circuit. There are two main types: air-to-air intercoolers, which use ambient air to remove heat, and air-to-water (or water-to-air) intercoolers, which circulate coolant through the unit. Some engines use multiple stages of intercooling or sequential turbocharging to manage boost across the operating range.

Intercoolers are usually located between the compressor outlet and the intake manifold, and their heat exchangers are sized to balance pressure drop with cooling capacity. Air-to-water intercoolers require a separate cooling loop and pump; air-to-air units rely on atmospheric airflow. Material choices commonly include aluminum for its heat transfer properties and light weight.

Benefits of intercooling include higher charge density, reduced tendency for knock, improved torque and horsepower, and the potential for more optimized ignition timing. Trade-offs or considerations include added system complexity, potential pressure drop, heat soak in high ambient temperatures, and additional weight and cost. Maintenance requirements can include cleaning fins and checking coolant levels in water-cooled designs.

Intercooling is common in forced-induction engines across automotive performance, diesel applications, and some aviation turbocharged engines. The concept dates from the mid-20th century and has evolved with advances in heat exchanger design and cooling technologies.