AP Racing CP9450 4-Piston Rear Big Brake Kit – Pro 5000R Series with EIAUFA Calipers

Description

AP Racing CP9450 4-Piston Rear Big Brake Kit

AP Racing Pro 5000 R — Radi-CAL™ Forged 2-piece

Upgrade your rear braking system with the AP Racing CP9450. This 4-piston forged 2-piece caliper delivers exceptional stopping power with even pad pressure distribution across all pistons, paired with EIAUFA rotors and EIAUFA RT550 performance compound for a complete bolt-on big brake kit solution.

Complete Kit Includes

Calipers	AP Racing CP9450 — 4-Piston, Forged 2-piece (pair)
Brake Discs	EIAUFA 2-piece floating rotors (355x32mm / 378x32mm)
Brake Pads	EIAUFA RT550 performance compound
Brake Lines	Goodridge stainless steel braided brake lines
Mounting Hardware	AME CNC-machined 7075-T6 aluminium bells & vehicle-specific brackets

Caliper Specifications

Caliper Model	AP Racing CP9450
Position	Rear
Pistons	4-Piston
Total Piston Area	27.2 cm²
Weight (per caliper, no pads)	2.21 kg
Construction	Forged 2-piece
Material	Aluminum
Finish	–
Mounting	Radial
Mounting Centers	152mm
Compatible Disc Range	362-378mm

Engineering & Technology

The CP9450 Pro 5000 R is a compact 4-piston rear caliper with 27.0/31.8mm differential bore pistons delivering 27.2 cm² at just 2.21 kg. Its 152mm Radi-CAL mounting centres and forged 2-piece construction make it the ideal lightweight rear companion to Pro 5000 R 6-piston fronts.

Performance Upgrade

• Fixed Caliper Design: Eliminates flex and provides consistent pad-to-disc contact across all pistons, unlike factory sliding calipers
• Differential Bore Pistons: Progressively sized pistons distribute clamping force evenly, eliminating tapered pad wear
• Increased Disc Diameter: Larger swept area dramatically improves heat dissipation and braking torque
• Reduced Unsprung Weight: Lightweight aluminum construction improves suspension response and handling

Compatible Pad Compounds

Use Case	Recommended Compounds
Daily Driving	EIAUFA RT550
Spirited Street + Track Days	EIAUFA RT550
Dedicated Track	EIAUFA RS830

EIAUFA Disc & Pad Options

Brake Discs:

• EIAUFA GG — 2-piece floating rotor with CNC-machined 7075-T6 aluminium bell (standard)
• EIAUFA HC — High-carbon rotor for improved thermal stability and crack resistance (upgrade)

Brake Pads:

• EIAUFA RT550 — Street/Daily compound
• EIAUFA RT550 — Street/Track compound
• EIAUFA RS830 — Track/Race compound

Custom Brake Solutions

At AME MOTORSPORT, we design and manufacture adapters for virtually every vehicle make and model. All our brake kits are engineered for direct bolt-on fitment across a wide range of vehicles.

• AME CNC-machined 7075-T6 aluminium disc bells & vehicle-specific mounting brackets
• Steel brackets available on request for heavy-duty applications
• Goodridge stainless steel braided brake lines
• All necessary mounting hardware included

Brake discs can be customised with square-slot pattern and full-floating conversion. Please contact us for consultation.

Need a different disc size, pad compound, or custom bracket solution? Contact us to discuss your specific requirements.

Warranty

Brake Calipers	1-year warranty against manufacturing defects
Brake Discs & Pads	Wear components — not covered under warranty
Defect Coverage	Includes cracking, material separation, or other failures without external force. Normal wear and damage from misuse are excluded.

Related Products & Guides

• EIAUFA Brake Pads for AP Racing CP9450
• EIAUFA Brake Rotors
• All Brake Pads
• All Brake Rotors
• AP Racing Big Brake Kit Collection

Lead Time: Approximately 5–14 business days.

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