ATI Pulley - AC - 4 Grv - AL - Rear - 10 Percent UD - Ford Coyote 5.0L

This ATI underdrive crank pulley is designed for Ford Coyote 5.0L engines. It's a rear, aluminum pulley with 4 grooves, intended for the AC system and features a 10 percent underdrive ratio. This means the accessories driven by the crank pulley, like the alternator and water pump, will spin at 90 percent of the engine's speed. This can help reduce drag on the engine, freeing up a small amount of horsepower and potentially improving accessory performance under load.

The aluminum construction helps keep the pulley weight down, which can contribute to quicker engine response. The 4-groove design is specific for applications using the AC system, ensuring all necessary accessories are driven correctly. Installing an underdrive pulley is a common modification for enthusiasts looking to gain a slight edge in performance by reducing parasitic drag from the engine's accessories.