Single Mass Flywheel

Lightweight flywheel for quicker, effortless revs that improve throttle response and free up lost horsepower. Tested and approved by our engineering team at Turner Motorsport. Tested in early, late, ETA and IS model E30s for confirmed fitment.

Introducing our Turner Flywheel: an ingenious blend of lightweight design, rich features, and remarkable strength! Crafted from 4140 HT Steel, this flywheel is precision-machined from a solid piece, ensuring unmatched durability. By strategically trimming excess weight from its original design, we've achieved a significant reduction in weight, giving new life to your M20 engine. With upgraded efficiency, your M20 can now swiftly spin to high RPMs, unleashing the full power and prowess of this formidable engine. Our flywheel features a ring gear profile compatible with all starters, alongside a reference tab tailored for early cars equipped with bellhousing-mounted sensor crank position detection.

Do you have an early model transmission with the crank sensors on the bellhousing? Maybe you have a late 325is with the crank sensor on the front of the engine, or maybe you have a 1988 super ETA. No matter which E30 model you have, our flywheel is the perfect choice for you.

During the engineering process we encountered the full spectrum of M20 and flywheel combinations. Early cars with bellhousing crank sensors, late cars with front mounting crank sensors and even a super ETA. On this adventure we found both early and late single mass flywheels and even the dual mass that we thought for sure was just a myth. At first we were hesitant that we could make one flywheel to fit them all but with the persistence of our engineering team(fleet of E30 enthusiasts) we can proudly say our M20 flywheel does in fact fit all engine and transmission applications you can think of.

Features and benefits:

Fits early and late models with M20
Fits shallow and deep bellhousing transmissions
Ring gear suited for both starters (P# 12411726504 + 12411361874)
Heavier than other lightweight flywheels, lighter than OEM, its like the Goldie Locks of flywheels - its just right
Reference pin for bellhousing crank sensor
Strong Single-Piece 4140 HT Steel construction
Designed to be used with factory and OE clutches
Weight Comparisons:

​Factory single mass flywheel EARLY (11221705046) - 23.69 lbs.
Factory single mass flywheel LATE (11221706573) - 18.74 lbs.
Dual mass flywheel (21211225979) - 27.56 lbs.
Turner flywheel - 14 lbs.
What you need:

Short bellhousing transmissions (I/IS) - Throw-out bearing P# 21517521471
Tall bellhousing transmission (ETA) - Throw-out bearing P# 21511204525

The factory BMW S65 dual-mass flywheel is engineered with comfort in mind, catering to the luxury-oriented expectations of the brand’s driving experience. Its design focuses on dampening drivetrain vibrations, smoothing out gear transitions, and minimizing harshness during operation. However, this refinement costs valuable performance. The dual-mass flywheel adds a substantial 27 lbs of rotational mass to the drivetrain, which significantly hinders throttle response and makes rev-matching feel sluggish and disconnected. Moreover, dual-mass flywheels are notorious for being a weak link in modified or high-performance builds and can prove costly to replace when they inevitably fail.

Our Single-Mass Lightweight Flywheel Conversion addresses all of these shortcomings with a purpose-built, lightweight, single-mass design that prioritizes performance. Weighing in at only 19 lbs., this design significantly reduces rotational mass, allowing your S65 to achieve its true motorsport potential!

Features & Benefits:

Precision machined from 4140 HT heat-treated chromoly steel for exceptional toughness, even wear properties, and increased durability.
Material quality promotes even wear across the entire friction surface, prolonging component lifespan.
Heat treated to HRC 28-32, tempered to relieve stress and improve dimensional stability.
Hardness improves component wear characteristics.
Black oxide coated for corrosion resistance on non-friction surfaces.
Precision balanced to exceed OEM specification (G16 spec to 175g-mm).
Specifically designed to work with S65 OE-architecture clutches.
Optimized step height maximizes clutch clamp load and offers a prolonged service life.
Performance:

8 lbs. lighter than the factory BMW flywheel!
OEM Dual-Mass: 27 lbs.
Turner Motorsport Single-Mass: 19 lbs.
Faster revs
Improved throttle response and acceleration
Allows for a more engaging driving experience and delivers a feeling of direct connection
Installation:

Flywheel Hardware: For added peace of mind, apply Blue or Orange Loctite when installing factory flywheel bolts that do not come with pre-applied threadlocker.