Upgrading to a midweight steel flywheel on your E39 has many advantages:
- eliminate potential failures from the original Dual-Mass Flywheel
- faster revs from less rotational mass
- more power to the wheels
Original Dual-Mass Flywheels (DMF) are a normal wear item. The internal rubber bushings, springs, and grease will wear out. A DMF should be replaced anyway on every other clutch job or upon inspection. Track use, hard launches, and abuse will decrease its usable life. A Single-Mass Flywheel does away with all of the complexity and potential failures of the DMF. It's made from a single-piece of machined steel or aluminum with a serviceable clutch contact ring. While aluminum flywheels are best for track applications or ultimate performance, a steel flywheel is our recommendation if the vehicle will be driven on the street since it will produce less noise and will be more pleasant for daily use. However, as a Single-Mass design it will have more noise and vibration than a stock Dual-Mass flywheel.
Even made of steel, this flywheel is still lighter than the stock dual-mass. With less mass to spin, the steel 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. This is especially appreciated with the S54 that lacks torque. The engine can also rev faster to get you into the power band sooner.
A lightweight flywheel does have some disadvantages compared to OEM:
- Engine revs drop quicker. A heavier flywheel will stay spinning while the lightweight loses revs faster. 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 lighter flywheel more.
- 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. Drivetrain noise is more noticeable and may irritate some drivers and passengers (steel is better than aluminum in this regard).
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.
Use only with an approved Clutch Masters clutch kit with sprung hub.