NOS

NOS is a nitrous oxide injection system that temporarily boosts an engine's power output by injecting nitrous oxide gas into the combustion chamber, allowing more fuel to burn and creating a sudden surge of extra horsepower.

The term "NOS" actually comes from Nitrous Oxide Systems, Inc., one of the first companies to manufacture these power-boosting systems for cars. Over time, racers started using "NOS" as a general term for any nitrous oxide system, similar to how people say "Kleenex" when they mean any tissue. When you hear someone in motorsport talk about "hitting the NOS," they mean activating their nitrous oxide injection system.

The science behind nitrous oxide systems is straightforward. Nitrous oxide is a chemical compound stored as a liquid under high pressure in a metal tank. When a driver presses a button or switch, the system releases nitrous oxide into the engine. The extreme heat inside the engine cylinder—around 300 degrees Celsius—breaks apart the nitrous oxide molecules into nitrogen and oxygen. This extra oxygen allows the engine to burn significantly more fuel than normal, creating a more powerful explosion that pushes the pistons harder and generates more horsepower.

There's an added benefit: nitrous oxide also cools down the air entering the engine. Cooler air is denser, meaning even more oxygen molecules can pack into the cylinder. This cooling effect combined with the extra oxygen from the nitrous oxide itself creates a double boost to engine power.

Nitrous systems come in two main types. A "dry" system injects only nitrous oxide, relying on the engine's existing fuel system to add the necessary extra gasoline. A "wet" system injects both nitrous oxide and additional fuel together, giving more precise control over the mixture but requiring more complex installation.

You'll most commonly see nitrous oxide systems in drag racing, where drivers need explosive bursts of power for short distances. Formula Drift competitions also allow nitrous systems to help drivers maintain speed and angle through corners. Some racing series have even created special classes specifically for nitrous-equipped cars, like "Pro Nitrous" in certain drag racing organizations.

However, most professional motorsport organizations actually ban nitrous oxide systems. The rules vary between different racing series, so competitors must always check their sanctioning body's regulations before installing a nitrous system.

Using nitrous oxide isn't without risks. The massive increase in power puts tremendous stress on engine components like pistons, connecting rods, and crankshafts. If the engine wasn't built to handle the extra force, parts can break catastrophically. The fuel-to-nitrous ratio must also be precisely calibrated—too much nitrous without enough fuel causes dangerous detonation that can destroy an engine in seconds. Proper installation, quality components, and careful tuning are essential for safe nitrous oxide use in motorsport.