Forced Induction - Water Injection

Water Injection

Water injection is another effective means of cooling the charge air to prevent detonation. Methanol is mixed with the water to prevent freezing and to act as a slower-burning fuel. Water injection, unlike nitrous oxide or forced induction, doesn't add much power to the engine by itself, but allows more power to be safely added. It works by being sprayed into the compressed air charge. The water absorbs heat as it evaporates to cool the charge and lower combustion temperatures. The alcohol is also a fuel in the charge which burns slower and cooler than gasoline. Due to the lower intake temperatures and denser air charge, more boost pressure and timing advance can be safely added without using higher octane fuel. It is most often used in racing applications, however it was also shown to be practical for extended use.