So on your endless pursuit of power, you might have stumbled upon light weight crank pulleys. But with that, you will notice an endless debate whether it would increase horsepower.
So what is a Lightweight Pulley?
Lightweight pulleys are attached to the outside of the crank shaft. These lightweight pulleys usually comes in a set that consists of the accessories pulleys and the underdrive pulley.
Accessories are pulleys are pulleys used to power car accessories such as the air conditioning, alternator, power steering etc… The underdrive pulley is designed to slow down the rotation of the accessory pulleys so they draw less power from the engine, and thus allowing for more power.
Pros of Lightweight Pulleys
By replacing your OEM pulleys which are usually created with heavy cast iron or steel with lightweight parts, you are effectively reducing the power needed to power your car accessories, thus recovering power that was lost to rotate the pulleys.
• Make your engine run more efficiently with less resistance
• Slight increase in HP (reported about 5-10WHP increases) Source: NonStopTuningUSA.com
• Improved throttle response
Cons of Lightweight Crank Pulleys
Poorly engineered pulleys will cause issues with your car accessories if it’s not spinning fast enough. This may cause low alternative voltage, weak power steering and no air conditioning.
In severe cases, the crank pulley can crack causing the shattered metal to fly around in your engine bay. This can seriously damage a lot of important engine components and cost you a ton in labor to get your car back up and running.
For a full blown race car, this modification is a no brainer. Little increase in HP, with the side effects on comfort. For those dailying their cars, this modification isn’t going to blow you away, but for $100 bucks, it’s not a bad performance mod for those looking to squeeze a little more power.