Audi S3 8P / 8V – BTCC Big Brake Kit – Nickel Plated AP Racing CP9660 18mm Pad Complete Upgrade | XC3 Engineering

XC3 Engineering BTCC Big Brake Kit – Audi S3 8P / 8V

Upgrade the braking performance of your Audi S3 8P or 8V with the XC3 Engineering BTCC Big Brake Kit, built around AP Racing CP9660 Pro 5000 R six-piston calipers, 368 × 36 mm ex-BTCC floating rotors and XC3 precision-engineered mounting components.

Designed for fast-road, trackday and clubsport use, this complete front brake upgrade increases thermal capacity, improves braking consistency and provides the S3 platform with a serious motorsport-derived braking package.

With a choice of anodised or nickel-plated AP Racing calipers, an 18mm pad format and included ex-BTCC Raybestos ST45 pads, this setup offers a strong balance of performance, consumable choice and value.

Why Choose the XC3 BTCC Big Brake Kit?

The standard Audi S3 braking system is capable for road use, but repeated hard braking can expose its limitations once power, tyre grip and track use increase.

Potential benefits of the XC3 BTCC setup include:

• Increased thermal capacity
• Improved braking consistency
• Better resistance to brake fade
• Stronger repeatability under heavy use
• AP Racing six-piston calipers
• Floating BTCC rotor design
• Motorsport-derived brake pads
• Suitable for fast-road, trackday and clubsport builds

AP Racing CP9660 Pro 5000 R Calipers

At the heart of the kit are AP Racing CP9660 Pro 5000 R six-piston calipers.

These are designed for serious performance and motorsport applications, offering strong rigidity, consistent braking response and reliable performance under repeated load.

Potential benefits include:

• Strong pedal response
• Consistent pad pressure
• High braking capacity
• Good modulation
• Proven track capability

Choice of Caliper Finish

The AP Racing CP9660 calipers are available in a choice of:

• Anodised finish
• Nickel-plated finish

The anodised finish provides a motorsport-inspired appearance, while the nickel-plated option offers a premium, corrosion-resistant finish.

18mm Brake Pad Format

The CP9660 uses an 18mm pad format.

This makes it a strong choice for trackday and clubsport applications where performance, pad availability and consumable flexibility are important.

For customers looking for a deeper endurance pad setup, the CP9668 25mm option may be more suitable.

368 × 36 mm Ex-BTCC Floating Rotors

The kit includes 368 × 36 mm ex-BTCC floating brake rotors.

These motorsport-derived discs provide substantial thermal capacity and are designed to cope with repeated high-energy braking.

The larger rotor size helps manage heat during:

• Long track sessions
• Repeated high-speed stops
• High-grip tyre use
• Aggressive road driving

Floating Rotor Design

The floating bobbin system allows the brake disc to expand in a controlled way as temperatures rise.

Potential benefits include:

• Improved thermal behaviour
• Better braking consistency
• Reduced thermal stress
• Greater repeatability under hard use

XC3 Anodised Rotor Bells

XC3 Engineering anodised rotor bells are included to correctly mount the BTCC rotors to the Audi S3 hub assembly.

They are designed to provide:

• Accurate rotor positioning
• Strong structural support
• Lightweight construction
• Reliable performance under load

XC3 Anodised Caliper Brackets

The supplied XC3 caliper brackets position the AP Racing CP9660 calipers correctly relative to the 368mm rotors.

Accurate bracket design helps maintain:

• Correct caliper alignment
• Proper pad sweep
• Consistent rotor positioning
• Reliable braking geometry

AP Racing Floating Bobbin Hardware

AP Racing bobbin kits are included to correctly mount the floating rotors to the XC3 bells.

These allow the disc assembly to function as intended under repeated temperature changes.

Braided Front Brake Lines

A pair of braided front brake lines is included.

Braided hoses can help reduce line expansion under pressure and contribute to a firmer, more consistent pedal feel.

Chemi Black High-Tensile Hardware

High-tensile Chemi Black bracket hardware is supplied with the kit.

This provides a strong and secure mounting solution for the conversion.

Ex-BTCC Raybestos ST45 Brake Pads

The kit includes inspected ex-BTCC Raybestos ST45 brake pads.

These provide a motorsport-derived friction option suited to demanding braking conditions and repeated track use.

Because the pads are ex-BTCC components, cosmetic marks and visible signs of previous use should be expected.

Improved Thermal Capacity

Higher speeds, more power and stickier tyres all increase the amount of heat generated by the brakes.

The combination of:

• 368 × 36 mm rotors
• Floating disc construction
• AP Racing CP9660 calipers
• Motorsport brake pads

creates a system designed to manage these loads more effectively than the standard front brakes.

Improved Braking Consistency

One of the key strengths of the setup is repeatability.

The kit is designed to maintain more consistent braking throughout:

• Long track sessions
• Repeated hard stops
• High-speed braking zones
• Aggressive fast-road use

Reduced Risk of Brake Fade

A larger rotor and motorsport caliper setup can help reduce the rate at which braking performance falls away as temperatures increase.

This can improve confidence during repeated high-load braking.

Ex-BTCC Rotor & Pad Condition

The supplied rotors and Raybestos ST45 pads are inspected ex-BTCC motorsport components.

This allows customers to access high-level competition hardware at a more cost-effective price point than an equivalent fully new setup.

Some cosmetic marks and evidence of previous motorsport use should be expected.

Ideal for Performance & Track Builds

This kit is particularly well suited to:

• Audi S3 8P track builds
• Audi S3 8V track builds
• Clubsport cars
• Higher-power road cars
• Semi-slick tyre setups
• Motorsport-inspired builds

Lifetime Warranty

XC3-manufactured components are covered by the XC3 Lifetime Warranty.

This provides additional confidence in the rotor bells and caliper brackets supplied as part of the kit.

Warranty terms and conditions should be checked before purchase.

Professional Installation Required

Professional installation is strongly recommended.

Performance braking systems are safety-critical and should be fitted by a suitably experienced technician.

Installation should include checks of:

• Caliper alignment
• Rotor alignment
• Hardware torque
• Brake hose routing
• Pad sweep
• Wheel clearance
• Full system bleeding

Wheel Clearance

Wheel clearance must be checked before ordering, particularly with aftermarket wheels.

Compatibility can depend on:

• Wheel diameter
• Spoke profile
• Offset
• Barrel clearance

Vehicle Fitment

Compatible with:

• Audi S3 8P
• Audi S3 8V

What's Included?

• 2 x AP Racing CP9660 Pro 5000 R six-piston calipers
• Choice of anodised or nickel-plated caliper finish
• 2 x Ex-BTCC 368 × 36 mm floating brake rotors
• 2 x XC3 anodised rotor bells
• 2 x XC3 anodised caliper brackets
• 2 x AP Racing floating bobbin kits
• 1 x Pair braided front brake lines
• Chemi Black high-tensile bracket hardware
• Ex-BTCC Raybestos ST45 brake pads

Explore More Audi S3 Braking

XC3 Engineering – Browse XC3 braking, chassis and motorsport components.

Brakes – Explore performance braking components and upgrades.

Brake Discs – Browse performance rotors and replacement brake discs.