Frequently Asked Questions (FAQs)
Performance pulleys, specifically underdrive pulleys, are designed to increase engine output by reducing the power draw of the engine's accessories. By slowing down the accessories, they reduce the horsepower they consume, resulting in increased engine performance.
2. How much HP does a pulley add?
Underdrive pulleys typically add around 10 to 12 horsepower to the engine's output. Turbocharged models may see even better power gains compared to naturally aspirated engines.
3. Do lightweight pulleys work?
Lightweight pulleys offer more noticeable benefits in first gear, but the difference becomes less apparent as you go higher in gears. While they do provide some advantages in terms of reducing rotational mass, the impact may not be as significant in higher gears due to limited traction.
4. What are the pros and cons of underdrive pulleys?
Underdrive pulleys offer pros such as power savings and reduced belt and component wear. However, there are also cons to consider, including power reductions, potential overheating, and the risk of low voltage that may conflict with certain high-energy aftermarket additions in your car.
5. Do bigger pulleys increase speed?
The size of the pulleys affects the speed and torque produced. A larger driven pulley will turn slower but produce more torque, while a smaller driven pulley will turn faster but generate less torque.
6. Do pulleys increase acceleration?
The acceleration of an object can be affected by the mass of the pulley. As the mass of the pulley increases, the acceleration of the object decreases. The specific calculation depends on factors like the mass and moment of inertia of the pulley.
7. Are aluminum pulleys better than plastic?
While plastic pulley stock is less durable compared to steel or aluminum, it can be preferred in certain applications due to its lightweight and cost-effectiveness. Plastic timing pulleys perform well in normal environments.
8. What is the most effective pulley?
Large sheave, ball-bearing pulleys are considered the most efficient. The weight savings of smaller sheave, ball-bearing pulleys are justified due to their improved efficiency.
9. Do underdrive pulleys increase mpg?
Underdrive pulleys, specifically aluminum underdrive crank pulleys, can provide benefits such as reducing accessory drag and improving fuel efficiency. By freeing up horsepower, they can also lead to gains in miles per gallon (mpg).
10. What does a 20 underdrive pulley do?
A 20% underdrive pulley, as the name suggests, reduces the parasitic power loss from driving engine accessories like the alternator, power steering, and air conditioning. By decreasing the load on these accessories, it increases horsepower and overall engine performance.
