Single Mass Flywheel

JB Racing Lightweight Aluminum Flywheel & Clutch Kit

T#:15777312

Part#: 520-040-215-KT

Back Ordered

$ 1,003.99

This product was last offered at the strikethrough price on
05-07-2026

$ 994.99 USD

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$ 994.99 USD

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A lightweight aluminum flywheel is a great way to increase throttle response and free up horsepower by reducing drivetrain loss. Factory flywheels are built to minimize engine and transmission vibrations, making them heavier and requiring more energy to make them spin. An aluminum flywheel can save lots of weight over the stock steel unit - sometimes over 50%. While the dampening effect of the stock flywheel is reduced, most enthusiasts would agree that the increase in performance is well worth it. In addition, the lighter flywheel allows the engine to spin more freely, improving throttle response. This JB Racing lightweight aluminum flywheel kit and is designed to be used with the included factory clutch, making replacement and service easy and inexpensive, especially compared to specialized racing clutches. It also preserves the driveability of your car on the street, and enthusiasts tolerant of a mild to moderate NVH increase will be especially taken with this setup. In addition, the JB Racing flywheel can be easily rebuilt with a new clutch contact surface, allowing you to enjoy faster revs and superior response for many years to come. Stock Flywheel Weight: 27 lbs. JB Racing Lightweight Aluminum Flywheel: 9 lbs.

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SPEC Aluminum Flywheel (SMF) (FOR USE WITH SPEC CLUTCH ONLY) 135 N55 ...

T#:597417

Part#: SB55A-2

Ships in 3 Business Days

$ 637.00 USD

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$ 637.00 USD

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MINI R52 R53 Lightweight Aluminum Flywheel (12lbs)

T#:31191877

Part#: SB09A

Ships in 3 Business Days

$ 499.00 USD

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$ 499.00 USD

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MINI R52 R53 Lightweight Aluminum Flywheel (12lbs) enhances the performance of the MINI with its precision engineering and lightweight design. This flywheel, manufactured by SPEC, is tailored for specific driving environments, making it ideal for both daily driving and high-performance applications.

Lightweight Design: Weighs approximately 12 lbs, reducing rotational mass for quicker engine response and improved acceleration.
High-Quality Construction: Made from premium steel and aluminum, ensuring durability and a flat seating surface for the clutch.
Precision Engineering: Manufactured to a .001 machine tolerance for smooth rotational qualities and perfect balance.
Performance Upgrade: Essential for converting from OE dual mass to single mass when used with SPEC Design clutch kits.
Versatile Application: Suitable for various driving habits and racing or high-performance setups.

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JB Racing Lightweight Aluminum Flywheel & Clutch Kit

T#:15677572

Part#: 21217528209-KT

In Stock

$ 1,386.99

This product was last offered at the strikethrough price on
06-04-2026

$ 1,307.99 USD

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$ 1,307.99 USD

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A lightweight aluminum flywheel is a great way to increase throttle response and free up horsepower by reducing drivetrain loss. Factory flywheels are built to minimize engine and transmission vibrations, making them heavier and requiring more energy to make them spin. An aluminum flywheel can save lots of weight over the stock steel unit - sometimes over 50%. While the dampening effect of the stock flywheel is reduced, most enthusiasts would agree that the increase in performance is well worth it. In addition, the lighter flywheel allows the engine to spin more freely, improving throttle response. This JB Racing lightweight aluminum flywheel kit and is designed to be used with the included factory clutch, making replacement and service easy and inexpensive, especially compared to specialized racing clutches. It also preserves the driveability of your car on the street, and enthusiasts tolerant of a mild to moderate NVH increase will be especially taken with this setup. In addition, the JB Racing flywheel can be easily rebuilt with a new clutch contact surface, allowing you to enjoy faster revs and superior response for many years to come.

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JB Racing Lightweight Aluminum Flywheel & Clutch Kit

T#:15710807

Part#: 520190240-KT

Ships in 2 Business Days

$ 1,060.99 USD

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$ 1,060.99 USD

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A lightweight aluminum flywheel is a great way to increase throttle response and free up horsepower by reducing drivetrain loss. Factory flywheels are built to minimize engine and transmission vibrations, making them heavier and requiring more energy to make them spin. An aluminum flywheel can save lots of weight over the stock steel unit - sometimes over 50%. While the dampening effect of the stock flywheel is reduced, most enthusiasts would agree that the increase in performance is well worth it. In addition, the lighter flywheel allows the engine to spin more freely, improving throttle response.

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Aasco Solid Billet Steel Flywheels N18 MINI Cooper

T#:37521038

Part#: 03-655

Ships in 10 Business Days

$ 799.99 USD

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$ 799.99 USD

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JB Racing Lightweight Steel Flywheel - Grand-Am Legal - E46, MZ3, Z4 ...

T#:40748575

Part#: 520010240SGA

Ships on Sep 3, 2026

$ 868.00 USD

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$ 868.00 USD

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This lightened steel flywheel is specifically designed (and approved) for use in Grand-Am road racing but can also be used as a mild street upgrade if a full aluminum lightweight flywheel is not called for. The Grand-Am flywheel is 20% lighter than stock to meet the rules for the GS and ST classes.Modern flywheels are built with additional components and features that are designed to dampen and minimize vibrations from the engine and transmission. As a result they have become bloated in weight and that means more energy is used up just making the flywheel spin. 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.

In addition to releasing more power to the wheels, the lighter flywheel allows the engine to spin more freely, which improves throttle response. The engine revs much faster than before. With the engine spinning easier the power band comes up much sooner. The stock steel flywheel feels lazy in comparison. There is a driving adjustment required to get used to how much faster the engine revs but that's not really a downside.

Grand-Am approved this flywheel to be used with a factory E36 M3 clutch. This opens up a lot of clutch and pressure plate options but we typically used this with a stock Sachs OEM clutch kit. This makes replacement clutch components easy to source and inexpensive when compared to specialized racing clutches.

Lightweight flywheels are considered 'single-mass' flywheels because they do not have the same dampening designs as an original 'dual-mass' flywheel. With a single-mass design more noise and vibration may be noticeable. There are steps you can take to minimize the noise - heavier weight transmission oil and clutch discs with anti-rattle springs (sprung-hub clutch). In addition to the standard replacement clutches, we also sell Sachs Performance sprung hub clutches that also work with the JB flywheels.

If being used on a 330i 6-speed or Z4 6-speed an additional pilot bearing hub is required. Select your appropriate model and transmission from the list below.

Stock Flywheel Weight = 25.0lbs
JB Flywheel Weight = 20.0lbs

This item fits the following BMWs:
2001-2002 E46 BMW 330i 330ci 5-speed
2003-2006 E46 BMW 330i 330ci 6-speed
2001-2006 E46 BMW M3
1998-2002 Z3 BMW Z3 M Roadster M Coupe
2003-2005 E85 BMW Z4 2.5i Z4 3.0i

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JB Racing Lightweight Aluminum Flywheel & Clutch Kit

SPEC Aluminum Flywheel (SMF) (FOR USE WITH SPEC CLUTCH ONLY) 135 N55 ...

MINI R52 R53 Lightweight Aluminum Flywheel (12lbs)

JB Racing Lightweight Aluminum Flywheel & Clutch Kit

JB Racing Lightweight Aluminum Flywheel & Clutch Kit

Aasco Solid Billet Steel Flywheels N18 MINI Cooper

JB Racing Lightweight Steel Flywheel - Grand-Am Legal - E46, MZ3, Z4 ...

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