BMW M5X to ZF 8HP45 Flywheel / Flexplate

Converting your BMW M50, M52 or M54 engine to a modern ZF 8HP45 automatic transmission? The KCPerformance BMW M5X to 8HP45 flexplate is designed to connect the BMW M5X crankshaft to a compatible torque converter, providing a solution for custom BMW automatic transmission conversions.

This BMW 8HP45 flexplate is suitable for BMW E46 8HP45 swap projects and other custom builds using BMW M5X-family engines. It is designed for use with the compatible BMW N20-style 8HP45 torque converter mounting configuration.

Important: Not all ZF 8HP45 transmissions use the same torque converter mounting geometry. Please read the compatibility information below carefully before ordering.

Designed for BMW M5X Engine Conversions

When installing a ZF 8HP45 automatic transmission behind a BMW M50, M52, M52TU or M54 engine, a suitable flexplate is required to connect the engine crankshaft to the transmission's torque converter.

This flexplate is designed for the BMW M5X crankshaft and the specified 8HP45 torque converter configuration. It provides a practical solution for BMW E46 transmission swaps and other custom BMW drivetrain projects without requiring you to develop a custom flexplate from scratch.

Torque Converter Compatibility

This flexplate is intended for the compatible BMW N20-style ZF 8HP45 torque converter mounting configuration.

Although the ZF 8HP45 transmission designation is the same, torque converters from different donor vehicles and engine applications can have different mounting surfaces, bolt patterns and offsets.

In particular, BMW N20 and N55 applications may use different torque converter mounting geometries. The N55-style torque converter may therefore not be compatible with this flexplate.

Do not assume compatibility based on the 8HP45 gearbox designation alone. Before ordering, verify that your torque converter matches the mounting configuration required by this flexplate.

If you are unsure which torque converter you have, contact KCPerformance before placing your order. Providing your donor vehicle details, transmission identification and photos or part numbers of the torque converter will help us assess compatibility.

Key Features

• Designed for BMW M50, M52, M52TU and M54 engines
• For ZF 8HP45 automatic transmission conversions
• Intended for the compatible BMW N20-style 8HP45 torque converter configuration
• Suitable for BMW E46 8HP45 swap projects
• Connects the BMW M5X crankshaft to the compatible torque converter
• Suitable for custom BMW drivetrain and performance projects
• Optional starter motor adapter available

Optional Budget Starter Motor Adapter

You can add our budget starter motor adapter when ordering the flexplate. This adapter is designed to position the original BMW starter motor correctly for the intended conversion setup.

If you already have a suitable starter motor adapter, you can order the flexplate on its own.

Please ensure that your starter motor and adapter are suitable for your specific engine and transmission combination.

Engine & Transmission Compatibility

• BMW engines: M50, M52, M52TU and M54
• Transmission: ZF 8HP45
• Torque converter: Compatible BMW N20-style mounting configuration required
• Typical application: BMW E46 8HP45 conversion
• Other applications: Custom BMW M5X engine conversions, subject to compatibility verification

Compatibility note: Compatibility with N55-style 8HP45 torque converters has not been confirmed. Check the torque converter mounting geometry before purchasing.

What's Included?

• 1x BMW M5X to ZF 8HP45 flexplate
  

This product is the flexplate only

Important Installation Information

This flexplate is intended for custom ZF 8HP45 transmission conversions and is not a complete conversion kit.

Depending on your vehicle and setup, additional components may be required, including a transmission mounting kit, transmission controller, wiring harness, driveshaft modifications and other conversion-specific hardware.

Before final assembly, verify the torque converter mounting pattern, alignment, offset and installation clearances. Correct compatibility and installation are essential for reliable operation.

If you need help selecting the correct components for your BMW 8HP conversion, contact KCPerformance before ordering. Our team can help you assess the requirements for your engine and transmission combination.