Crank pulleys, attached to the outside of the crankshaft, are the source of power for a car's accessories. The alternator, power steering, water pump, and air conditioner are all belt driven units, attached to the crank pulley, that use horsepower from an engine to provide their own services. Underdrive pulley systems increase an engine's horsepower by reducing the power required to drive the external engine accessories. By replacing factory pulleys with carefully resized units, the accessories are slowed enough so that their performance does not suffer, but just enough so that more horsepower is sent to the wheels and put to the ground. Where horsepower should be! :vroam:
Normally, underdrive pulleys will increase engine output by 8 to 15 horsepower, with even better power levels yielded from turbo models than seen in normally aspirated engines! This increase results in quarter-mile time improvements of .2 to .25 seconds, easily making this modification one of the best "bang for your buck" modifications for any sport compact car. :trytofly:
Another great benefit in replacing factory pulleys with underdrive units is reduced weight. Factory units, also referred to as OEM, are generally constructed from steel or cast iron. Resized pulley systems are constructed of aircraft quality aluminum, making them extremely durable while at the same time much lighter than their steel counterparts. This increased weight reduction results in less rotating mass on the engine's crankshaft which drastically increases the engine's ability to rev up to speed faster. Better throttle response = big grin on a driver's face! :cheers:
Increased weight reduction :top:
Increased horsepower :top: :top:
Lower ET's & higher trap speeds :top: :top: :top:
Normally, underdrive pulleys will increase engine output by 8 to 15 horsepower, with even better power levels yielded from turbo models than seen in normally aspirated engines! This increase results in quarter-mile time improvements of .2 to .25 seconds, easily making this modification one of the best "bang for your buck" modifications for any sport compact car. :trytofly:
Another great benefit in replacing factory pulleys with underdrive units is reduced weight. Factory units, also referred to as OEM, are generally constructed from steel or cast iron. Resized pulley systems are constructed of aircraft quality aluminum, making them extremely durable while at the same time much lighter than their steel counterparts. This increased weight reduction results in less rotating mass on the engine's crankshaft which drastically increases the engine's ability to rev up to speed faster. Better throttle response = big grin on a driver's face! :cheers:
Increased weight reduction :top:
Increased horsepower :top: :top:
Lower ET's & higher trap speeds :top: :top: :top:
