Established in 1998, China Xiaowei Bearing Co., Ltd. is a high-tech enterprise specializing in underdrive pulley manufacturer and design many kinds of bearings. We have a modernized staffs of tech research and fog machine development, ISO9001 certificated, and manufacturing adopts advanced domestic and foreign standards such as GB, API, JIS, DIN, BS, NF and ANSI.

BBK Performance underdrive pulley kits are built from aircraft-quality, computer-machined steel or aluminum alloy. By reducing the speed of the accessories, these underdrive pulleys free up an average of 8-15 hp, while retaining full cooling and charging characteristics. Most kits can be bolted on in less than 30 minutes.The pulleys are then media blasted for a satin silver finish and lasered with the Agency Power name (not shown). Our Agency Power pulley weighs less and with a smaller diameter increases power and performance.

Underdrive pulley systems (smaller pulleys that allow your engine's alternator, water pump, etc. to spin faster) are generally used to allow your alternator to spin faster and produce maximum power just above idle. However, a great side effect is that the water pump will now spin faster and move more fluid, thereby cooling your engine a bit more efficiently. There is a point however, where you can move too much water too quickly through your radiator and engine, and not give it enough time to effectively cool down, so don't go underboarder, overboard. March Performance is a great source for underdrive pulley kits, serpentine conversions and more.