Pulley's

[carkid0007]

What am I looking for when I look for a Pulley kit ?, What exactly does it do ?, What brand is best ?

[misnomer]

Wow

OK, pulleys attach to the front of the crank and have belts going to all the motor accessories (A/C, power steering, fan, water pump, alternator, I miss anything?).

Aftermarket pulley sets typically will have two advantages.

First is they are going to be lighter weight, reducing the rotational mass on the engine and freeing up some parasitic loss of power (not much, but some).

Second, and most significantly, most aftermarket pulley sets are what are called "underdrive" pulleys. This essentially means they have a smaller diameter. Smaller diameter gears and pulleys turn slower, but require less power to do so, further reducing parasitic power loss.

Asp and Unorthodox Racing are the only two pulley makers that I can recall for the 240sx. I don't know the differences well enough to expand on which of them to choose.