What is an Airfoil?
An airplane wing has a special shape called an airfoil. As a wing moves through air, the air is split and passes above and below the wing. The wing’s upper surface is shaped so the air rushing over the top speeds up and stretches out. This decreases the air pressure above the wing. The air flowing below the wing moves in a straighter line, so its speed and air pressure remain the same. Since high air pressure always moves toward low air pressure, the air below the wing pushes upward toward the air above the wing. The wing is in the middle, and the whole wing is “lifted.” The faster an airplane moves, the more lift there is. And when the force of lift is greater than the force of gravity, the airplane is able to fly.
An airfoil is a specific shape, notably that used in airplane wings, which helps generate lift. In addition to airplane wings, which are the most well-known airfoils, fans, propellers, and some stabilizers are also in the shape of an airfoil. In nature, the airfoil is a very common shape, found in plants and in creatures that fly through the air or swim through the water. The basic principle by which an airfoil operates is referred to as lift. The shape of an airfoil is such that wind can pass both above and below it. The shape of the top is designed so that, as air passes over it, it speeds up, decreasing the air pressure in that region according to Bernoulli’s principle. Air below the airfoil is not affected, so its speed is the same as it was when it first contacted the airfoil. Air with a higher pressure tends to move towards air with a lower pressure, and this difference in pressure causes force to be exerted beneath the airfoil, generating lift. The faster the air is moving – or
Simply put, all airfoils are designed with one objective in mind, better, improved airflow into the intake of the engine. With this comes the expectation of better throttle response and claimed horsepower gains. The Hypertech/TPIS style airfoil is the type that is held into the throttle body by a bolt and special nut that’s dropped from the top of the throttle body (removing the top plate.) The following instructions demonstrate how to install this type of airfoil on 305/350 TPI engines.
