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Underdrive Pulleys
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<blockquote data-quote="fabianyee" data-source="post: 120915" data-attributes="member: 6"><p>actually underdrive pulley is smaller in diameter. </p><p></p><p>Visualize the front ring gears on the bicycle. the bigger the ring gear, the more effort u need to pedal it. the smaller the front ring gear the lesseffort required to pedal. </p><p></p><p>Smaller pulley on the crank means smaller circumferrence, hence less belt travel for every revolution, hence 'underdriving' the alternator, powersteering pump, fan clutch and waterpump.</p><p></p><p>As for the case of the bigger pulley on the MCS, it's to increase the boost on the supercharger. There are 2 ways of doing that. one is bigger crank pulley, the other is smaller supercharger pulley.</p></blockquote><p></p>
[QUOTE="fabianyee, post: 120915, member: 6"] actually underdrive pulley is smaller in diameter. Visualize the front ring gears on the bicycle. the bigger the ring gear, the more effort u need to pedal it. the smaller the front ring gear the lesseffort required to pedal. Smaller pulley on the crank means smaller circumferrence, hence less belt travel for every revolution, hence 'underdriving' the alternator, powersteering pump, fan clutch and waterpump. As for the case of the bigger pulley on the MCS, it's to increase the boost on the supercharger. There are 2 ways of doing that. one is bigger crank pulley, the other is smaller supercharger pulley. [/QUOTE]
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