Car engines produce power through an internal combustion process. In this process, air is drawn into the engine cylinders, where it is mixed with fuel. The piston then compress the air-fuel mixture in the cylinder, after which it is ignited by the spark plug. The energy released in this ignition forces the piston back down the cylinder. In this way the pistons constantly drive the rotation of the crankshaft, which translates into horsepower. After each combustion cycle, the remnants of the air-fuel mixture are forced out of the cylinder and into the exhaust system.
Turbochargers are the ultimate way to squeeze the maximum amount of horsepower possible out of an internal combustion engine. However, to run efficiently, turbochargers require an entire system of piping and sensors in order to monitor and circulate the pressurized air as it is fed into the throttle body. An important part of most turbo systems is the intercooler, which is designed to cool down the turbocharged air before it enters the engine. The necessity of an intercooler system is due to the extreme level of heat generated by a turbocharger setup.
On a turbo setup, the turbocharger is installed in the path of the exhaust flow. When the engine is accelerated and exhaust volume increases, the turbocharger exhaust wheel begins to rotate, or spool. This in turn spools the compressor wheel, connected by a shaft to the exhaust wheel. The compressor wheel thus draws in ambient air and pressurizes it as it is forced into the engine. Because the pressurized air is much more dense than ambient air, the engine has much more air and fuel in the cylinders during each combustion cycle, which substantially increases horsepower.
The intercooler system is located between the turbocharger and throttle body. When in operation, the turbocharger produces substantial amounts of heat. This in turn heats the ambient air as it's pressurized by the turbine. Featuring a radiator installed in the path of oncoming air, the intercooler lowers the temperature of the turbocharged air before it is routed into the throttle body. Without an intercooler, a turbocharged engine is much more prone to premature detonation in the cylinders, caused by the high heat of the incoming air being sufficient enough to ignite the air-fuel mixture.
Benefits and Disadvantages
Because cooler air is more dense, intercooler systems allow a turbocharger to force more air into the engine cylinders for each combustion cycle, improving both horsepower and efficiency. Intercoolers also allow the engine to run more smoothly and reliably, especially in hot climates. However, a disadvantage of using an intercooler system is an effect known as "pressure drop." This means that the turbocharger has to work harder to maintain its set pressure level since it is required to pressurize the interior area of the intercooler system. Furthermore, high-boost turbo setups often require large, front-mounted intercoolers. Because they are installed in front of the radiator system, front-mount intercooler setups can increase the risk of engine overheating.