Single Mass Flywheel

The factory BMW S55 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 26.5 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 18.5 lbs., this design significantly reduces rotational mass, allowing your S55 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).
SFI 1.1 certified to ensure safe operation under extreme operating conditions.
Specifically designed to work with S55 OE-architecture clutches.
Optimized step height maximizes clutch clamp load and offers a prolonged service life.
Performance:

10 lbs. lighter than the factory BMW flywheel!
OEM Dual-Mass: 26.5 lbs.
Turner Motorsport Single-Mass: 18.5 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.

Engineered in-house, we designed this lightweight, single-mass flywheel to provide more than 10 pounds of weight savings over the factory flywheel. While some ultra-lightweight performance flywheels are manufactured from aluminum, our designers opted for a more driveable experience with steel. The mass provided by steel helps dampen vibrations and noise, delivering near-factory refinement with most of the benefits of a lightweight flywheel: quicker throttle response, improved durability (and longevity), and more effective transfer of power to the wheels.

Modern flywheels are built with additional components that are designed to dampen and minimize vibrations from the engine and transmission. Weight has increased and reliability has decreased. With additional weight more energy is required for it to move. A lightweight flywheel does away with the dual mass design and its additional mass so more energy can be diverted to where it counts most - moving the car. The flywheel and clutch is one of the first areas that engine builders address when making the rotating assembly lighter for race engines. The dampening effect is just not needed on cars that are focused on performance. And with a single-mass flywheel the unreliable DMF design is eliminated.

When it comes to selecting a clutch to pair with a lightweight flywheel, consider the driving you’ll be doing. As a single mass flywheel eliminates the dual-mass dampening of the factory flywheel, to retain the lowest noise, lowest harshness driving experience possible, select a clutch with a dampened disc such as the ACT Heavy Duty. For dedicated track cars, a solid clutch hub is appropriate.

Our recommendations:

Street: ACT Heavy Duty
Track: ACT Xtreme for high torque cars or OE 335is LuK (with 440lbs-ft or less)
Features:

Precision machined from 4140 HT heat treated chromoly steel for exceptional toughness, even wear properties, and durability.
Material quality promotes even wear across the entire friction surface
Heat treated to HRC 28-32, tempered to relieve stress and improve dimensional stability and elevated temperatures
Hardness improves wear characteristics
Black oxide coated for corrosion resistance on non-friction surfaces.
8620 steel pilot bearing pin, case hardened and Precision ground for maximum wear resistance.
Precision balanced to exceed OEM specification (G16 spec to 175g-mm).
SFI 1.1 tested and certified to ensure safe operation under extreme operating conditions
SFI 1.1 specifies minimum material properties and requires a 3rd party lab certification test, spinning the flywheel to 1.5x redline for 1 hour to ensure the flywheel will not burst.
Specifically designed to work with N54 architecture clutches
Step height designed to optimize clamp load and maximize the usable range of clutch wear for a long service life
Performance:

Turner Flywheel 18.6 lbs
10 lbs lighter than the factory BMW flywheel (Stock Flywheel 28.9 lbs)
Faster revs
Improved throttle response
Improved acceleration
Sportier driving experience
Stock flywheel weight - 28.9lbs
Turner single mass flywheel weight = 18.55lbs

Single Mass Flywheel Conversion:

Audible chatter from the transmission after installation is considered normal. As with most single mass flywheels, there is less dampening in the flywheel to reduce "gear noise." This chatter noise may be more present when the transmission fluid temperatures are hotter and may be intensified by other modifications. Most gearboxes will experience some chatter noise at hotter temperatures. Please be advised that this noise will disappear once the clutch pedal is depressed. This symptom may be lessened by adjusting transmission fluid weight, turning off electrical/driveline consumers (A/C, High Beams, ETC.), and by raising the RPM slightly.

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.

This item fits the following BMWs with 8 bolt flywheel and build date up to 01/2009 or earlier:
2008-01/2009 E82 BMW 135i 135is 1M
2007-01/2009 E90 BMW 335i 335xi 335i xDrive - Sedan
2007-01/2009 E92 BMW 335i 335xi 335i xDrive - Coupe
2007-01/2009 E93 BMW 335i - Convertible
2008-01/2009 E60 BMW 535i 535xi 535i xDrive

Turner Motorsport Lightweight N54 Flywheel & Upgraded Clutch Kit

Unlock the full potential of your N54-powered BMW with our performance-driven clutch and flywheel kit. Designed to enhance daily drivability while delivering increased power handling and improved throttle response, this kit is the ultimate upgrade for enthusiasts seeking more from their vehicle.

Why Choose This Kit?
This setup features the Turner Lightweight N54 Flywheel, precision-engineered for quicker acceleration, faster rev-matching, and a more responsive driving experience. Paired with an upgraded OE clutch from the high-performance 335is and F10 550i(V8 Bi-Turbo), this combo is capable of handling over 500 ft-lbs of torque while maintaining smooth, factory-like engagement and durability.

The factory dual-mass flywheel may prioritize smoothness and efficiency, but it comes at the cost of responsiveness and is prone to failure in high-performance applications. The Turner Lightweight Flywheel solves these issues with a single-mass design that strikes the perfect balance between comfort, performance, and reliability making it ideal for both daily driving and spirited track use.

Kit Contents:

Turner Lightweight N54 Single-Mass Flywheel (18.6 lbs, 10 lbs lighter than stock)
Upgraded OE Clutch – Supports 500 ft-lbs+
OE Clutch Fork - P# 21517564027
OE Throwout Bearing
Clutch Alignment Tool - P# 056212LA01A
Brass Clutch Fork Pivot Pin - P# 21511223328
OE Flywheel Bolts - P# 11227520706
OE Pressure Plate Screws - P# 21207548052
Pivot Pin Retaining Spring - P# 21517570284
Transmission Mating Dowels - P# 11117524470
Flywheel Features:

Precision-machined 4140 HT heat-treated chromoly steel for durability
Black oxide coating to resist corrosion
8620 steel pilot bearing pin for maximum wear resistance
Precision balanced to exceed OEM standards
Optimized step height for longer clutch life and consistent performance
Clutch:

Upgrade for 135i/335i/535i models from the 335is! Featuring a heavy-duty clutch with more holding power and a stock-like pedal feel. Excellent solution for If your clutch is slipping, or the engagement isn't what it used to be, it's time for a replacement. Slipping clutches won't allow your BMW to accelerate properly and can pose problems under a load such as going up large inclines. Also, a worn clutch can cause less precise and engaging shifts. By replacing your clutch you will restore performance and driving pleasure.

This clutch is an excellent upgrade for non 335is/550i/650i models. It features a more heavy-duty clutch disc and more holding power with stock-like pedal effort.

Transform your driving experience with this Turner Motorsport clutch and flywheel kit - engineered for power, performance, and everyday reliability.