If you own an M57-equipped BMW, you already know this twin-turbo diesel powerplant is an absolute torque monster. What you might also know is that all that low-end grunt and high-compression diesel vibration wreaks absolute havoc on your accessory drive system.

From the factory, both the E90 335d and E70 X5 35d utilize a rigid alternator pulley. With each cylinder's fire, the crankshaft experiences a violent micro-acceleration. Because the alternator has a heavy internal rotor spinning at high speeds, it wants to keep spinning at a constant rate. When the engine suddenly slows down (even minutely between firing cycles), the alternator fights the belt. This constant tug-of-war results in extreme stress on your engine's belt-driven components. At best, it’s an annoying, unrefined chirp at idle; at worst, it’s a ticking time bomb for your expensive harmonic balancer.

To solve this issue, many enthusiasts choose to run a clutched alternator pulley (also called an overrunning alternator pulley). A clutched pulley allows the alternator to "freewheel" or coast when the engine slows down, completely isolating its rotational inertia from the belt drive to prevent component wear. While the N52's clutched pulley (12317560483) is a straight bolt-on, the offset is incorrect for the E90 335d's accessory drive. Thankfully, our engineers designed this zinc-coated spacer to provide the precise amount of spacing needed to perfectly align the new pulley with existing belt drive components.

Over time, accessory belts begin to wear out and crack. This can lead to the belt slipping, squeaking, or even snapping. Replace your belts and tensioners on a regular basis to ensure you don't end up stranded on the side of the road with a dead battery or over heated engine due to a bit of simple overlooked maintenance. This kit includes all of the items that will need replaced such as the belts, tensioners, and hardware.

Fits the following BMWs:
1996-2003 E39 BMW M5

Over time, accessory belts begin to wear out and crack. This can lead to the belt slipping, squeaking, or even snapping. Replace your belts and tensioners on a regular basis to ensure you don't end up stranded on the side of the road with a dead battery or over heated engine due to a bit of simple overlooked maintenance. This kit includes all of the items that will need replaced such as the belts, tensioners, and hardware.

Fits the following BMWs:
09/2002-2006 E53 BMW X5 M54
09/2002-2003 E39 BMW M54
09/2002-2005 E46 BMW M54

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

NOW LOCATED UNDER T#340397

BMW E46 Z3 M54 Turner Motorsport Power Pulley Kit - 325i/330i: Boost Your BMW's Performance

• Increases horsepower and torque
• Improves throttle response
• Lightweight aluminum construction
• Easy to install with basic tools

Upgrade your BMW's performance with the BMW E46 Z3 M54 Turner Motorsport Power Pulley Kit - 325i/330i. This kit increases horsepower and torque, resulting in improved acceleration and overall driving experience. The lightweight aluminum construction reduces rotational mass, enhancing throttle response and engine performance. Installation is easy with basic tools, making it a convenient upgrade for BMW enthusiasts. Access Secret Premium Dashboard

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!

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.

* Alternator Pulley Options

Bosch or Valeo? BMW built your car with either a Bosch or Valeo brand alternator. Unfortunately, the pulley is not the same for both brands. The brand is usually printed on the black plastic cover of the alternator but may be facing the frame rail or the ground. If you know which brand you have, select your option below and we'll send you the correct alternator pulley for your BMW. Don't know which you have? NO PROBLEM! We can send you both. The 2nd pulley costs $40 but you will receive a refund once we get the un-used pulley back (return shipping not included).

Stereo Systems. We offer our kits in two different ways: the full Power Pulley Kit with all 3 pulleys or as a 2 pulley kit if you do not wish to underdrive your alternator (for large stereo systems or other critical-charging modifications). Our kits have been tested for compatability with the factory premium stereo systems (Harmon Kardon, etc). But any major upgrades from the factory premium systems will work best with our 2 pulley kit and no underdriving of the alternator. For all stock stereo systems the full 3-piece set is recommended because the Turner alternator pulley will help make more power and is also much lighter than the stock pulley.

Additional Info

Clickhere for example dyno graph

Click here for installation instructions.

Turner Pulley Kit contents:

• Turner water pump pulley
• Turner power steering pump pulley
• Turner alternator pulley
• new extended length belt
• instructions
  
  
   
• This underdrive pulley kit fits the following BMW:
  1997-1998 E39 BMW 528i

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

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!

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.

* Alternator Pulley Options

Bosch or Valeo? BMW built your car with either a Bosch or Valeo brand alternator. Unfortunately, the pulley is not the same for both brands. The brand is usually printed on the black plastic cover of the alternator but may be facing the frame rail or the ground. If you know which brand you have, select your option below and we'll send you the correct alternator pulley for your BMW. Don't know which you have? NO PROBLEM! We can send you both. The 2nd pulley costs $40 but you will receive a refund once we get the un-used pulley back (return shipping not included).

Stereo Systems. We offer our kits in two different ways: a full power kit with all 3 pulleys or a 2 pulley kit for people who do not wish to underdrive their alternator (for large stereo systems or other battery-draining modifications). Our kits have been tested to be compatible with the factory premium stereo systems (Harmon Kardon, etc). But any major alterations or upgrades from the factory system may work best with our 2 pulley kit and no underdrive of the alternator. Otherwise, the 3 pulley kit is recommended because it not only underdrives the alternator but the Turner pulley is much lighter than the stock one.


Additional Info

Clickhere for example dyno graph

To learn more about Turner Power Pulleys, click here.

This Power Pulley Kit Fits the Following BMWs:
2000-2006 E53 BMW X5 3.0i

Shark Injector Performance Software
The enthusiast's choice for over a decade, the Shark Injector's performance is only equaled by its own ease of install! Tune your ECU at the press of a button simply by plugging into the under-dash OBDII diagnostic port, there is no removal of your car's computer; no laptop or cables required. What does the Shark offer?

• Excellent horsepower and torque gains - peak: 18whp/11wtq, max: 22whp/16wtq
• Faster and smoother throttle response
• Top speed limiter removed
• Extremely easy to install/uninstall
• Reversible and reusable
• Elevated 8,250 RPM rev limiter
• Compatible with 91 octane; 93 recommended

​Turner Motorsport Power Pulleys 
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! We measured 10.7 whp at 6960 rpm and 8.1 lb-ft of torque at 5550 on a 1995 M3. Race pulleys deliver even more power. 

Another "no-downside" upgrade, we even include a new belt. Total install time for a 3-piece pulley set should be around 1.5 hours. We offer three options in pulleys:
1.) No alternator pulley included - for cars with big amps and powerful stereo systems that need the extra juice.
2.) Street Power Pulleys - our most popular option with no downside!
3.) Race Power Pulleys - delivering 15 "free" horsepower, this set underdrives the water pump, power steering pulley, and alternator for lower temps, less wear, and more power. Not for street use. 

Intake Air Temperature Relocation Kit
Looking to maximize your power gains? Add a Turner IAT Relocation to combat power-robbing heat soak - the only true plug-and-play solution available. Heat soak is a real plague on consistent power for a stock or tuned vehicle. Click here to read more about our IAT relocation kit.

This item fits the following BMWs:
2001-2006 E46 BMW M3