Clutch Masters FW-340-AL Aluminum Flywheel for BMW M240i/340i/440i/GR Supra B58

Vehicle Fitment

• 2016-2018 BMW 340i / 340i xDrive (3.0L B58 Turbo I6, F30, 6-Speed Manual Transmission)
• 2017-2020 BMW 440i / 440i xDrive (3.0L B58 Turbo I6, F32/F33, 6-Speed Manual Transmission)
• 2017-2020 BMW M240i / M240i xDrive (3.0L B58 Turbo I6, F22/F23, 6-Speed Manual Transmission)
• 2023-2025 Toyota GR Supra (3.0L B58 Turbo I6, A91, 6-Speed Manual Transmission, RWD)

Fitment Notes

• 6-speed manual transmission only - does not fit 8-speed automatic (ZF 8HP) equipped models
• BMW B58 3.0L turbocharged inline-six engine only - does not fit B48 2.0L 4-cylinder models (230i, 330i, 430i) unless specifically noted, and does not fit the S55 engine (M3/M4)
• This is a standalone flywheel - not a complete clutch kit; designed for use with Clutch Masters single disc clutch kits on the 03058 / 16340 platforms
• Replaces factory dual-mass flywheel with a lightweight aluminum single-mass flywheel
• Includes replaceable steel friction insert - eliminates need to resurface or replace the entire flywheel at future clutch services
• Aluminum flywheels are recommended for race and track applications; Clutch Masters recommends the steel flywheel (FW-340-SF) for primarily street-driven vehicles as aluminum flywheels may produce increased gear noise
• Replacing a DMF with a single-mass flywheel may cause gear rattle and vibration that may not be suitable for all drivers

Features

• Lightweight aluminum flywheel machined from 6061-T6 billet aluminum
• CNC-machined to exact tolerances for perfect fitment - designed in CAD and precision machined in-house on Haas CNC lathes
• Type 3 hard coat anodized (Mil-Spec) for exceptional durability, heat resistance, and corrosion protection
• Precision zero-balanced during machining for even weight distribution and 100% true rotation
• Replaceable steel friction insert - eliminates need to resurface the flywheel; simply replace the insert at each clutch service
• Significant weight reduction over factory dual-mass flywheel for faster engine acceleration, quicker revs, and improved throttle response
• Reduces turbo lag by decreasing rotational inertia on the crankshaft
• SFI certified to spec 1.2 for competition in NHRA, NDRA, IDRC, IHRA, SCCA, and NASA
• Designed and manufactured in the USA

Specifications

• Type: Lightweight single-mass aluminum flywheel
• Material: 6061-T6 billet aluminum, Type 3 hard coat anodized
• Friction Surface: Replaceable steel insert (included)
• Weight: 16 lbs
• SFI Certification: Spec 1.2
• Country of Manufacture: USA

Included Components

• 1x 6061-T6 billet aluminum flywheel (CNC-machined, Type 3 hard coat anodized, zero-balanced)
• 1x Replaceable steel friction insert (pre-installed)
• 1x Pilot bearing (when applicable)

Product Description

The Clutch Masters FW-340-AL is a lightweight aluminum flywheel designed for the BMW B58 3.0L turbocharged inline-six platform with 6-speed manual transmission. This flywheel covers the 2016-2018 BMW 340i, 2017-2020 BMW 440i, 2017-2020 BMW M240i, and the 2023-2025 Toyota GR Supra manual - all of which share the BMW B58 engine. At 16 lbs, it provides a dramatic weight reduction over the factory dual-mass flywheel, resulting in significantly faster engine acceleration and deceleration, quicker rev-matching, reduced turbo lag, and sharper throttle response throughout the powerband. The B58 engine responds exceptionally well to reduced rotational mass, and the difference in driving feel is immediately noticeable from the first blip of the throttle.

The flywheel is CNC-machined from a solid 6061-T6 billet aluminum core sourced from US manufacturers and guaranteed free of impurities or defects. Every flywheel is precision zero-balanced during machining to ensure even weight distribution and 100% true rotation at high RPM. The Type 3 hard coat anodizing (Mil-Spec) provides the ultimate protection against wear, heat, and corrosion on the aluminum surface. The replaceable steel friction insert is a key feature - rather than resurfacing the flywheel at each clutch service, the insert can simply be replaced, extending the flywheel's usable life indefinitely and reducing long-term maintenance cost.

Clutch Masters recommends aluminum flywheels primarily for track, race, and aggressively driven applications where minimal rotational mass is the priority. For primarily street-driven vehicles, the steel flywheel (FW-340-SF) is recommended as it produces less gear noise and provides a more refined daily-driving experience. Replacing the factory dual-mass flywheel with any single-mass flywheel may introduce some gear rattle and vibration that is normal but may not be desirable for all drivers. The flywheel is SFI certified to spec 1.2 for sanctioned competition and is proudly designed and manufactured in the USA on in-house Haas CNC lathes. This flywheel is designed for use with Clutch Masters single disc clutch kits - for twin disc applications on this platform, use the twin disc-specific flywheel variant.