Jet computer chip

[Mr. Tune]

Underdrive pulleys replace the stock pulleys for the alternator, water pump and crank. Aftermarket ones "underdrive" your accessories by slowing them down, thus generating more power.

[Michowski]

o ok. Were can you get them at?

[Thirdgen89GTA]

Generating more power isn't really the right term. Its more like the relationship between the gears on a pedal bike.

Because the pullies are smaller they are easier for the engine to spin. And because they spin easier, they cause less parasitic loss. So the engine can use more of its inertia to spin the output shaft.

However, because the accesories are underdriven the alternator makes less power, less power is available to power your accessories. The water pump has less flow, so cooling capacity is reduced.

There are advantages and dissadvantages each way.

[Michowski]

well for most people that would be true cooling wise. My 160 thermostat already barely lets my engine get 1/4th the way up the temp guage. Also with the electric fan I can control if I want it to get cooler or warmer. Cooling wouldnt be an issue for me. And for power it would hardly be that much at all. Nobody would probly even notice it because it wont effect anything.