Underdrive Power Pulleys work to 'free up' horsepower. Any accessory that spins from the main drive belt is using up power. That's power that could otherwise be used to move the car. By giving some of that power back to the engine, you can make the car faster! It's like FREE HORSEPOWER! We measured 10.7 whp at 6960 rpm and 8.1 lb-ft of torque at 5550 on a 1995 M3.

Underdrive pulleys for your BMW will slow down engine-mounted accessories - the water pump, power steering pump, and alternator*. These systems contribute to 'parasitic losses' - power lost from what the engine could produce if it did not have these systems. Since less energy is used to move them, that power is transferred back to the engine and used to propel the car. Our pulleys give a 10-20% reduction in rotation, releasing up to 11hp on most BMW six-cylinder engines. There's also a small but noticeable improvement in throttle response too! We have done extensive testing and development work, both on and off the track, to ensure that the accessory systems function as they should. On our Racing pulley kits we actually underdrive certain components more so we feel our Street pulleys are an ideal compromise between power/torque gains, reliability, and system performance. Our pulley kits have been on the market for over ten years, and used in all of our own cars, with zero component failures related to their use.

Our pulleys are made from T-6061 aluminum and finished in a durable black hard anodize that is very resistant to wear, chemical exposure, and heat. We designed our pulleys to look similar to the factory parts but also to be stronger and, in most cases, slightly lighter too. For example, a Turner alternator pulley is less than half the weight of the stock steel pulley! With our hardcoat aluminum you will never have to worry about a serious failure of a stock plastic pulley. A 'stealth' approach to aesthetics was our goal and we let the results speak for the pulley design. Installation is straight forward and easy with simple hand tools. Removal of the fan is required for access to the front of the engine. Total install time for a 3-piece pulley set should be around 1.5 hours. A new longer belt is included and we also recommend replacing the separate A/C belt, belt tensioners, and the guide and deflection pulleys at the same time.

BMW M50 S50 S52 Turner Motorsport Power Pulley Kit: Boost Your BMW's Performance

• Increases horsepower and torque
• Improves throttle response and acceleration
• Lightweight design reduces rotating mass
• Precision-engineered for perfect fitment

Upgrade your BMW's performance with the BMW M50 S50 S52 Turner Motorsport Power Pulley Kit. This kit is designed to increase horsepower and torque by reducing the rotational mass of the engine's accessories. With improved throttle response and acceleration, you'll experience a more dynamic driving experience. The lightweight design of the pulleys reduces rotating mass, resulting in improved engine efficiency. Plus, each pulley is precision-engineered for perfect fitment, ensuring seamless integration with your BMW's engine. Access Secret Premium Dashboard

Enhance your BMW's performance with the BMW E46 Z3 Turner Motorsport Power Pulley Kit 325i/330i Valeo Alternator. This high-quality power pulley kit is designed to increase horsepower and torque by reducing parasitic drag on the engine. With easy installation and precise fitment, this kit is a must-have upgrade for any BMW E46 or Z3 owner.

• Increases horsepower and torque
• Reduces parasitic drag on the engine
• Easy installation process
• Precise fitment ensures optimal performance

Rogue Engineering has developed a power pulley kit that reduces the drag on specific pulleys while allowing others to remain at their same efficiency. This allows for perfect operation in daily driven vehicles without a hiccup or stutter. However, when the demand for power is requested, the power pulley kit allows for the freed power to become apparent.  The term "power" pulley is a bit of a misnomer. Underdrive pulleys actually free up power by reducing the drag caused by the accessories.  These pulleys are based off a calculated percentage from factory dimensions, so that particular component speeds are safely reduced without affecting their true purpose.

Rogue Engineering Power Pullies are CNC machined from 6061-T6, heat treated aluminum and specially coated with a MIL-A-8625 Type III hard coat anodize finish. This kind of anodizing is not to be confused with a Type II cosmetic anodize finish (typical colors such as red, blue, silver, green, etc.). The hard coat anodize finish actually builds a small surface layer on top of the aluminum, preventing wear.

This part fits the following BMW engines:
S54

This part fits the following chassis:
E46, Z3, Z4