Includes crank, alternator, and idler pulleys. UR claims gains of 10-14hp with a 62.5% reduction in weight over the stock pieces!
This set increases performance by reducing the engines spinning weight and also because it underdrives the accessories. All the underdriving is done with the crank pulley, not the accessory pulleys. This is done to maximize the weight loss at the crank where most of the horsepower gains are realized. UR was very careful not to over-do the amount of underdrive for two main reasons. First, it is important to keep the alternator, air conditioning, power steering, and water pumps moving fast enough for every day driving. Second, not much horsepower is gained from extreme underdriving.
Lightweight, stock diameter (non-underdriven) pulleys also available. Contact us for more info.