This OEM Ruville hydraulic tensioner assembly is designed to keep the serpentine belt at the correct pressure against the pulleys. Many BMW's can have either a hydraulic or mechanical belt tensioner. Please check to see which tensioner type you need before ordering.

OEM Schaeffler (INA, LuK, Ruville, & FAG) is an engineering company that focuses on high-performance, precision manufacturing. With their individual brands INA, Luk, and FAG providing exceptionally high quality parts directly to BMW, as well as countless other automotive companies, their history of reliability and variety of offered parts makes Schaeffler a go-to replacement parts provider for all of us here at Turner Motorsport.

As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts.  All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

This item fits the following BMWs:
1992-1998 E36 BMW 323is 323ic 325i 325is 325ic 328i 328is 328ic M3
1999-2005 E46 BMW 323i 323ci 325i 325ci 325xi 328i 328ci 330i 330ci 330xi M3
1991-1995 E34 BMW 525i
1997-2003 E39 BMW 525i 528i 530i

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

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

M7 Speed 4% Oversize Crankshaft Pulley for MINI Cooper

Unlocking Performance

The M7 Speed 4% oversize crankshaft pulley is your ticket to unlocking the hidden potential of your MINI Cooper. This performance-enhancing pulley is designed to add power, acceleration, and overall performance to your beloved MINI. Here's how it does the trick:

Performance Boost:

• Safely speeds up your supercharger, delivering a significant "low end" boost and torque.
• The result? Your MINI Cooper takes off with newfound energy and responsiveness.

Lightweight Advantage:

• Weighing just 13 ounces, this pulley is a remarkable 88.5% lighter than the factory version.
• Reduced crankshaft rotational mass equals more horsepower, torque, and improved throttle response.

Advanced Design

The M7 Speed 4% Crank Pulley isn't just about performance; it's also a work of art. Crafted with advanced computer modeling and precision CNC machining, it's a blend of form and function:

Materials:

• Made in the USA from billet 6061-T6 aerospace-grade aluminum alloy.
• Features a deep black anodized coating and laser etching for a sleek look.

Precision Machining:

• Micro V-Belt grooves meet SAE J1459 specifications to minimize belt slippage, especially at maximum boost.

Optimal Fit:

Use it in conjunction with the M7 Speed 16% Supercharger Technology Pulley for peak performance in MINI tuning.

Reliable Performance

From the factory, MINI lacks a positive drive key on the crankshaft snout to drive the lower pulley. Most aftermarket pulleys are slip-fit and rely on the bolt to prevent slippage. The M7 Speed crank pulley is engineered differently:

Interference Fit:

The pulley is interference-fit onto the crankshaft, ensuring zero slippage even at high RPMs.

Features at a Glance:

• Super Lightweight: Only 13 ounces (0.3 kg)
• Sheds 6.2 lbs (2.8 kg) compared to stock
• Achieves perfect balance through a symmetric design and precision machining
• Includes a high-quality ARP Racing bolt and precision ground flat washer
• Installation is a breeze

Unleash Your MINI's Potential

Proudly made in the USA, the M7 Speed 4% Oversize Crankshaft Pulley is the upgrade your MINI Cooper deserves. Unleash its hidden power and enjoy a new level of performance, reliability, and overall driving pleasure. Get ready to experience the difference.