Nitrous Oxide

Forcing more air into your engine so it burns more fuel is the basic concept behind superchargers and turbochargers. Another way to achieve this type of power boost is to change the actual content of the air charge. That's what happens when you add nitrous oxide, similar to the gas used by dentists to dull your senses. When injected into your engine, however, the effect is anything but dull. That's because it raises the oxygen concentration of the air from a typical figure of 20 percent (at sea level, less at higher altitudes) to a much higher level, so the engine can burn more fuel and produce more power.

Pluses
The big advantage of nitrous is that it provides power on demand at the touch of a button. Otherwise, you don't even notice it's there. Also, a nitrous system is a lot less expensive and generally easier to install than a turbo or blower.


An extra bonus of nitrous oxide is the lowering of the intake temperature. When released from a pressurized bottle, the temperature of nitrous oxide drops to around minus 125 degrees, which can cool the overall intake charge by as much as 65 degrees, resulting in even more horsepower.

Direct Port

Nitrous systems consist of two basic types: dry manifold and direct port. The less expensive dry manifold design uses a single nozzle mounted in the throttle body or a plate underneath the carburetor, so it's also fairly easy to install. The direct-port systems have a fogger nozzle in each intake runner for a more complete and efficient distribution of nitrous oxide gas. This setup requires a more elaborate (and expensive) arrangement of tubing and a distribution block.


A simple injector spray-bar plate nitrous-oxide system is fine for street performance and certain classes of racing. When you need to add more than 350 horses, though, a direct-port system is the way to go. The extra tube-bending work required typically costs about $250 for most applications.