The aftermarket auto parts industry is what is referred to as a secondary market. This secondary market is filled with alternative, extra and sometimes used used engines performance auto parts that do not come with a vehicle in “stock”, also known as factory condition. Aftermarket performance parts are installed vehicle parts, chemicals, equipment and tools or other accessories which are available after the original sale of the vehicle by the original equipment manufacturer (OEM) company.
The aftermarket auto parts and accessories business does upwards of $250 billion in the United States alone. These types of products cover replacement parts (due to age or accidents) and tweaks to performance, appearance or tuning, even electric and alternative fuel conversion. However the bulk of the aftermarket performance auto parts industry is indeed for tuning and often full-on racing. This industry also employs nearly 5 million people in the United States, via manufacturing companies, distribution companies, retail and repair shops.
Turbochargers, which are different than superchargers or twinchargers, are perhaps the most popular aftermarket performance racing parts. A turbo charger is centrifugal compressor. This compressor receives power from the engines exhaust gases via a turbine. The compressor uses forced induction (increased air pressure on entrance) to increase power and efficiency depending on the setup.
Turbochargers weigh little and have a small size for the boost that they provide. These factors make them ideal for smaller vehicles looking for a big boost in speed, power and acceleration. Most high performance auto parts stores will sell multiple variations of turbo kits. These turbo kits provide all the parts needed to turn your vehicle into a turbocharged one. Some turbo kits also provide the so-called “twin-turbo” option.
Twin-turbos feature two turbochargers to compress the air intake charge. They most commonly come in parallel and sequential setups. Parallel twin-turbo setups use identically turbochargers which split the work. Sequential turbo kits make use of two turbochargers, one is used at lower engine speeds and the other is for higher engine speeds. Each is designed to operate properly at differing speeds. The final type of twin-turbo is the “staged turbo”. In the staged setup multiple turbos of the same size are used but both are continually operating “in sequence” to provide the increased pressure.