NOS, or Nitrous Oxide Systems, is a performance enhancement that injects nitrous oxide (N₂O) into a car's engine to provide a significant, short-term power boost. Often called "nitrous" or a "shot," it works by releasing extra oxygen into the combustion chamber during combustion, allowing the engine to burn more fuel and produce a dramatic increase in horsepower and torque. This is a popular aftermarket modification for drag racing and street performance.
The core principle involves two main effects. First, the nitrous oxide decomposes when heated, releasing oxygen (which supports more vigorous combustion) and nitrogen (which helps control combustion temperatures). Second, the process of the nitrous oxide vaporizing creates a intake charge cooling effect, making the air entering the engine denser and further increasing potential power output.
However, NOS is not without significant risks. The sudden stress can damage engine components not built to handle the extra power, including pistons, connecting rods, and head gaskets. Proper installation is critical and must include safety components like a window switch (to only activate within a specific RPM range) and a fuel pressure safety switch. It's also crucial to understand that NOS is designed for short bursts, not continuous use. For sustained power, forced induction systems like turbochargers or superchargers are more reliable alternatives.
| Feature | Typical NOS "Shot" (e.g., 100 hp) | Turbocharger |
|---|
| Power Delivery | Instant, "on/off" torque hit | Builds with engine RPM (boost lag) |
| Complexity | Relatively simple mechanical system | More complex, involves exhaust gases |
| Cost | Lower initial installation cost | Generally higher initial and setup cost |
| Usability | Short-duration bursts only | Can provide increased power continuously |
| Engine Stress | Sudden, intense stress on components | Stress is more progressive and manageable |
