BitViper

iTrader: (63)

Whats the diameter on that. I bought a ASP crank pulley off someone which came with a smaller pully for the alternator....Im trying to determine if the alternator pulley is an Overdrive or under drive

BitViper

iTrader: (63)

so..I got smart and went out and measured the existing pulley 2.5" andteh new pulley which is 3"...Im guesing that it IS and OVER drive pulley

TheBlurLS1

iTrader: (8)

A LARGER alternator pulley means it's UNDERDRIVE, it's backwards from the crank.

The larger pulley means more belt will have to pass by for it to turn the same number of revolutions, making it underdriven. Should be worth an extra 1-3hp, but you may run into charging issues with both installed.

JZ28

iTrader: (3)

I have the ASP pulley set installed on my '00 Z. It does struggle for voltage at idle, but it has not caused any problems for me. I am pretty sure that the pulley I have for the alt is an overdrive pulley though. I think that with an underdrive pulley, you would have some problems.

DONAIMIAN

iTrader: (18)

All the reason to run a bigger cam so youll have a reason to set the idle higher.

BitViper

iTrader: (63)

Silver cloud ehhh!