Hi guys. This is some of the modifications that i've done to my engine which is lighten crank pulley. At first i don't really think that this thing can do wonder but No! this is a very good upgrade for engine. It makes the engine feel lighter and rev climbs faster than before until you reach the redline. Seriously no joke!
By the if you are thinking what is crank pulley, it is the main pulley on the end of the crank (duh) that drives the accessories -- alternator, water pump, and air conditioning compressor =)
p/s: mine is lightened and undersized crank pulley .. absolutely lighter than oem. Damn fast response!