Underdrive pulley systems increase engine horsepower by reducing the amount of power required to drive external engine accessories. For example, the alternator, power steering, water pump and air compressor rob horsepower from the engine. By replacing factory-sized crank and accessory drive pulleys with a resized pulley, the accessories are slowed, resulting in more horsepower available to the drive wheels. Typically, a set of Auto Specialties street pulleys will increase horsepower by 12-15, and increase mileage by 2 to 3 MPG. All pulleys are manufactured from Billet Steel or Aluminum, exceeding factory quality.
Due to the difference in diameter from the stock Mustang pullies, the alternator and charging system may need to be upgraded if you have a large stereo system.
These ASP Mustang underdrive pullies work great on a stock or modified V8 GT or LX Mustang!
ASP - Quality. Performance. Products.
ASP is one of the industry's leading producers of Mustang performance pulleys. Since 1988 ASP has been machining underdrive pulleys in house to give you the most performance for your Mustang. Each pulley goes through a CNC lathe for accurate measuring and cutting. The pulleys go through 2 cycles and a quality check to ensure each part is perfect before it leaves out of the door.