my b16 is underdriven with a unorthadox pulley. its the single one liek mentioned above. thats all i got on it though no other lightened pulleys. i have a 800watt system in my car too. i havent drained my battery or anything but i also have a steffening capacitor for my system. with the crank and the lightweight flywheel its a considerable difference (or atleast it was until i did my other stuff) when i raced stock B16's.