BMW M2 F87 / M3 F80 / M4 F82 BTCC Custom Rotor Bells – 368 mm × 36 mm for AP Racing CP9660 Calipers | XC3 Engineering

XC3 Engineering BTCC Custom Rotor Bells – BMW M2 F87 / M3 F80 / M4 F82

Upgrade your BMW F8x braking setup with XC3 Engineering BTCC Custom Rotor Bells, designed for use with 368 × 36 mm BTCC-spec brake rotors and AP Racing CP9660 calipers.

Machined from high-quality 6082-T6 aluminium, these bespoke rotor bells provide the critical interface between the factory BMW front hub and the upgraded motorsport brake rotor.

Designed for precision, durability and reliable alignment, they are ideal for trackday cars, clubsport builds and high-performance road applications using a serious AP Racing / BTCC-style front brake setup.

Why Choose XC3 BTCC Rotor Bells?

The rotor bell plays an important role in ensuring the brake disc is mounted accurately and securely to the hub.

XC3 Engineering developed these bells specifically for the BMW F8x platform to support 368 × 36 mm BTCC rotor conversions.

Potential benefits include:

• Accurate rotor positioning
• Lightweight aluminium construction
• Strong and rigid mounting
• Designed for AP Racing CP9660 brake conversions
• Suitable for demanding road and track use
• Precision CNC machined
• Direct compatibility with OEM front hubs

Key Features

• Designed for BMW F87 M2, F80 M3 and F82 M4
• Compatible with 368 × 36 mm BTCC-spec rotors
• Designed for AP Racing CP9660 brake setups
• 6082-T6 aluminium construction
• Precision CNC machined
• Black anodised finish
• CNC engraved XC3 logo
• Designed and manufactured in the UK
• Suitable for track, clubsport and performance road builds

6082-T6 Aluminium Construction

The rotor bells are manufactured from 6082-T6 aluminium.

This material provides a strong balance of:

• Low weight
• High strength
• Rigidity
• Durability

This makes it well suited to performance braking applications where accurate component positioning and low rotating mass are important.

Precision CNC Machined

Each rotor bell is CNC machined to achieve accurate dimensions and repeatable fitment.

Precise machining is especially important in brake assemblies, helping ensure the disc sits correctly relative to the hub and caliper.

Designed for 368 × 36 mm BTCC Rotors

The bells are designed specifically around compatible 368 × 36 mm BTCC-spec brake rotors.

These rotors are commonly used in high-performance and motorsport braking systems where heat management and repeatability are essential.

Designed for AP Racing CP9660 Calipers

The XC3 rotor bells are intended to form part of a brake setup using AP Racing CP9660 calipers.

When combined with the correct caliper carriers, rotors and hardware, they provide the basis for a serious motorsport-inspired front brake conversion.

Lightweight Performance Design

Using an aluminium rotor bell helps reduce unnecessary weight compared with a fully one-piece disc arrangement.

Lower rotating and unsprung mass can benefit:

• Suspension response
• Steering feel
• Acceleration
• Overall chassis performance

Black Anodised Finish

The rotor bells are finished in black anodising for improved corrosion resistance and long-term durability.

The anodised finish also provides a clean, professional appearance.

CNC Engraved XC3 Logo

Each bell features a CNC engraved XC3 logo for a high-quality finished appearance.

Track & Clubsport Applications

These rotor bells are particularly well suited to:

• Trackday builds
• Clubsport cars
• Time attack-inspired setups
• High-performance road cars
• Semi-slick tyre builds

Direct Fitment to OEM Front Hubs

The bells are designed for BMW F8x models using standard OEM front hubs.

No alternative hub conversion is required.

Works as Part of a Complete Brake Conversion

These rotor bells are designed to be used with the other components required for a complete front brake conversion, including:

• AP Racing CP9660 calipers
• XC3 caliper carriers
• 368 × 36 mm BTCC rotors
• AP Racing rotor bobbins
• Performance brake pads
• Braided brake lines
• High-temperature brake fluid

Lifetime Warranty

XC3 Engineering backs this product with a lifetime warranty.

This provides additional confidence in the strength and durability of the component.

Warranty terms and conditions should be checked before purchase.

Professional Installation Recommended

Professional installation is strongly recommended.

A braking system is safety-critical, so all components should be assembled and installed by an experienced technician.

Installation checks should include:

• Rotor alignment
• Caliper alignment
• Hardware torque
• Wheel clearance
• Brake hose clearance
• Pad position

Vehicle Fitment

BMW F8x

Compatible models:

• BMW F87 M2
• BMW F87 M2 Competition
• BMW F80 M3
• BMW F82 M4

Designed for:

• OEM front hubs
• 368 × 36 mm BTCC-spec rotors
• AP Racing CP9660 caliper setups

What's Included?

• XC3 Engineering BTCC Custom Rotor Bells

Related Components

Suitable supporting parts include:

• 368 × 36 mm replacement BTCC rotors
• XC3 caliper carriers
• AP Racing CP9660 calipers
• AP Racing rotor bobbins
• Performance brake pads
• Braided brake lines
• High-temperature brake fluid

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