Aluminum Lightweight Flywheel, Clutch Masters - E9X M3 6MT 08-13

The BimmerWorld View: aluminum flywheels offer substantial increases in performance, quicker engine revs, and more power to the wheels. It also removes the dual-mass feature of the stock flywheel which has been a failure point for us in the past. But lightweight also has a few downsides. Aluminum flywheels are so light that they lose almost all of their dampening effects and have more noise and vibration. Also, the revs drop faster during shifts, requiring an adjustment period to get perfect rev matching. In our opinion, lightweight flywheels are worth giving up some refinement for the performance gain and improving reliability.

Upgrading to this 14lb lightweight aluminum flywheel on your E90/E92/E93 M3 (S65 Engine) has many advantages:
 

• eliminate potential failures from the original Dual-Mass Flywheel
• faster revs from less rotational mass
• more power to the wheels

Upgrading to an aluminum flywheel not only has performance benefits but is also a smart move to prevent a potentially catastrophic flywheel failure. Aluminum flywheels are a single-mass design - machined from 6061-T6 aluminum with a replaceable steel clutch plate. This makes the flywheel lighter and simpler, two things that are appreciated for better performance and reliability. Because aluminum is the lightest flywheel available we recommend this for mostly track-focused cars. Steel is also available for performance street use.

Performance
With less mass to spin the aluminum flywheel returns horsepower and torque to the engine. Less power is needed to spin the flywheel and clutch. While engine horsepower doesn't change, more power makes its way to the wheels, making the car faster at all RPM and any speed. The engine can also rev faster to get you into the power band, and turbo boost, sooner.

Reliability
The stock dual-mass flywheel (DMF) is a normal wear item. The DMF is made up to two halves with rubber and grease between them. Track use, hard launches, and abuse will decrease its usable life. If not replaced preventatively the DMF breaking apart inside the bellhousing - the two flywheel halves separate, the clutch breaks apart, and grease is scattered everywhere. The transmission usually survives a DMF failure but spinning ring gears have been known to slice through bellhousings. The DMF should be replaced about every other clutch job under ideal normal circumstances.

Service
Abusing the clutch on a stock DMF will leave clutch material deposits on the surface and excess heat may warp the material or burn up the lubricating grease. The clutch surface on a DMF is usually not thick enough for it to be machined, requiring replacement of the whole flywheel. An aluminum single-mass flywheel has a replaceable steel clutch surface. If the steel shows signs of excess wear, remove the steel plate and replace it with a new one for much less than the cost of a new flywheel.

An aluminum flywheel does have some drawbacks that you need to be made aware of:
- Engine revs drop quicker. A heavier flywheel will stay spinning while the aluminum loses revs faster. This can make heal-and-toe and matching revs more difficult. Most drivers adapt quickly and it becomes a non-issue. In fact, going back to a heavier DMF, such as when driving a student's car at a driving school, is a downgrade that makes them appreciate their aluminum flywheel more.
- A steel single-mass flywheel will be a better option for turbocharged cars. The aluminum is so light that revs drop too fast and you can easily fall out of boost. The steel SMF will be more reliable and lighter than a DMF but still not drop revs as quickly.
- Part of the reason a DMF was installed in the first place was to dampen and absorb driveline vibrations and noise. The two plates suspended in rubber do a great job of smoothing out engine vibrations. An aluminum flywheel has very little dampening in comparison. Drivetrain noise is much more noticeable and may irritate some drivers and passengers. A heavier steel single-mass flywheel is also available that has more dampening capability.

Clutch Masters is the authority on performance clutch and flywheel innovation. With decades of experience in all forms of motorsport, including drag racing and drifting, Clutch Masters has the expertise to design and develop BMW clutch and flywheel upgrades that are overbuilt for their intended use. They apply the same approach for bulletproof performance for a BMW engine as they do for a 900hp drag car. All of their flywheels are SFI certified for use in motorsports.

Clutch Options: a single-mass flywheel should not be used with an OEM clutch. Our strong recommendation is a Clutch Masters clutch that matches your performance needs and has a sprung center hub (dampened). The dampened clutch will greatly reduce noise and vibration and make the clutch easier to live with for normal use. Our most popular clutches for a E9X M3 lightweight flywheel are the Clutch Masters FX100 or FX350 clutch kits.

2008 fitment note: BMW had a different 6MT flywheel and clutch for cars produced up to 9/2008. The 2008 parts have been discontinued and superseded to the 2009+ parts. When purchasing a lightweight flywheel choose any “dampened” E9X M3 6MT clutch (sprung hub). If you have a 2009-2013 M3 6-speed, this flywheel is a direct replacement and no other parts are required.

Clutch Return Spring: BMW also recommends replace the return spring on the clutch pedal arm if it has not already been replaced. See BMW part #35006769442 under the Related Items below. Even if it has been replaced it may not be a bad idea to change it anyway.