When it comes to engine performance, air is essential. The more air your engine can get, the better it can work. A high-flow air filter can increase your horsepower by 3 to 5 HP and torque, as well as improve fuel efficiency. For example, the 14-inch by three-inch element in 1960s-era Chevy high-powered car air filters is ideal for many single-carburetor applications.
It's important to note that high-performance air filters are considered a modification and may void your warranty if you have a new vehicle that is still within the warranty period. If the filter were after the turbo, then the volumetric flow would be lower for the forced induction setting. People choose to spend money on this basic and easy modification for a few reasons. The guys at Engine Masters tested all kinds of air filters and found that turbulence in the filter has more effect on performance than anything else.
The shape and size dictate the ability of the air filter element to flow the maximum amount of air into the engine. For maximum airflow, you need the largest air filter element or assembly that fits within the engine or engine compartment limits. Companies like K&N offer many different types of air filter elements and air filter assemblies to fit various sizes and shapes of carburetors. Fuel economy is improved because high-performance air filters draw air from outside the engine compartment, where the air is colder.
This colder air is denser than the warm air inside the engine compartment, which is heated by internal combustion and other frictional heat sources. In addition, a properly sized air cleaner assembly with a high flow element can increase the amount of air flow in the carburetor. I currently have a SUPER DIRTY K&N air filter that fits in front of my radiator through custom pipes. The high-performance air filter will not only slightly increase your power, but it will also improve the fuel economy of your vehicle.
