Ram air utilizes the design of a vehicle's hood to maximize engine performance. Standard hoods, including hoods with scoops designed only for appearance, are closed to outside air whenever the vehicle is being driven. Because of its simplicity, the closed hood is the most common factory-installed design.
A ram air hood, however, is not completely closed. Openings, or slots, are cut into the top of the hood. These openings are designed to force cool air into the engine compartment when the vehicle is driven at road speeds. The most effective ram air hoods are designed to channel this outside air directly into the air intake system of the engine.
Ram air hoods function in two important and related ways. First, cool air from outside the vehicle is pushed into the engine compartment. As the car accelerates to higher speeds, more air is channeled into the ram. A properly fitting ram hood is designed to function best under speed, making it most effective when the engine is working the hardest.
Additionally, openings and cutouts in the rear of the ram air hood allow heat buildup within the engine compartment to dissipate. These rear cutouts are called heat extractors. By allowing heat to escape efficiently, extractors make room for even more fresh air from the ram. The cooler the compartment is kept, the more efficiently the engine will run.
To operate at peak performance, an engine must have access to oxygen. Because cold air is naturally more dense than warm air, it contains higher amounts of oxygen. This increased oxygen delivered through a ram air hood is vital to the combustion and performance of the engine.
Typically, vehicles with ram air installed have increased amounts torque and horsepower as well as better fuel economy. This increase in performance is highest when the vehicle is at highway speeds and enables quicker acceleration with less wear on the engine.
