overdrive alternator pully

[Kal-El]

i read from zzperformence that the overdrive alternator pully increase the output of your alternator by 10% so if are alternator is stock 105 will this bring it up higher and if so by how much and by doing this will i lose hp? thanks

[TopHatJimmy]

It won't make the alternator produce any more power overall, but it will make the alternator produce higher amps at lower rpms because it will be spinning faster than stock at any given RPM.

Stock 105A alt puts out around 45 amps at idle (700 engine RPM, 2100 alternator RPM. Stock alt pulley is on a 3:1 ratio with the crank). If the gain is 10%, the alt will now produce around 50A at idle and continue to produce until it hits it's peak output of around 105A.

These pulleys work really well if you have an HO alternator where the output falls way off at idle. Put an undersized pulley on it to get it to spin faster than normal at idle to bring the power output up at that RPM.

Kinda confusing, but think of it as changing the power band of your alt. It's not making any more power, just making power in a different RPM band.