Which pulley turns fastest?
In a pulley system, the smallest pulley usually turns fastest because it requires more revolutions to navigate the same length of the belt. Pulleys of Different or Same Size If two pulleys of the same size are connected by a belt, as one turns, the second one will turn at the same speed with the same power available at the shaft. If a smaller pulley turns a larger one, the larger one will turn slower, but with more power available at the shaft.The driven pulley is adjustable and the drive pulley is controlled by a mechanical action that will open or close the pulley based on rpm requirement. As the driven pulley is opened, the driven pulley will decrease in speed and the opposite, as the drive pulley is closed the driven pulley will increase in speed.
Do pulleys increase horsepower?
When you use an underdrive pulley, you can make major horsepower gains. Because they replace stock water pumps, power steering, AC units and alternators, you may even notice increased acceleration when you choose an underdrive pulley. Horsepower gains from underdrive pulleys can vary by vehicle, engine, number of accessories and the amount of underdrive (improvements of up to 5–15 HP at the wheels have been seen). Additional and significant performance improvements can be seen by reducing the weight of the pulley versus the original pulley.