SPEC Stage 4 Clutch Kit

2004–2008 Subaru Impreza WRX STI 2.0L Turbo

Part #: SU304

Overview

The SPEC Stage 4 Clutch Kit is designed for Subaru WRX STI owners seeking enhanced performance and durability for aggressive driving, racing, and high-power applications. Built to withstand the demands of spirited driving, this clutch kit offers a significant upgrade over stock components, providing improved grip, quicker engagement, and reliable operation under stress. Whether you're participating in drag racing, rally, road racing, or pulling, the Stage 4 kit delivers the strength and performance needed to handle increased horsepower and torque.

Engineered for enthusiasts who demand more from their vehicle, the Stage 4 Clutch Kit ensures your Subaru WRX STI can handle high-power modifications while maintaining streetability. It strikes a balance between aggressive engagement and drivability, making it suitable for daily drivers who push their cars on weekends or track days.

Key Features

The SPEC Stage 4 Clutch Kit incorporates advanced materials and design features to maximize performance and longevity. Key features include:

• Solid hub design with an 8-rivet construction for increased strength and durability, reducing the risk of hub failure during high-stress driving.
• Heat-treated components that enhance the clutch's ability to withstand extreme temperatures generated during aggressive driving or racing sessions.
• Available in multiple puck configurations—3, 4, or 6 pucks—allowing you to choose the optimal setup for your driving style and application.
• The 3-puck option offers the lightest engagement and is ideal for street use, providing quick throttle response with minimal pedal effort.
• The 4-puck configuration offers a balanced compromise between street and race performance, delivering improved grip without excessive chatter or harshness.
• The 6-puck setup provides the smoothest engagement and is best suited for drag racing and high-power applications where maximum holding capacity is required.
• Designed to support increased horsepower and torque, helping you push your vehicle to its limits with confidence.

Construction & Design

The SPEC Stage 4 Clutch Kit features a high-performance ceramic or metallic friction disc, engineered for aggressive engagement and heat resistance. The clutch assembly is meticulously heat-treated to ensure long-lasting performance and resistance to warping or glazing. The pressure plate is designed with reinforced springs and a robust diaphragm to provide consistent clamping force, ensuring reliable power transfer during high-RPM shifts and rapid acceleration.

The solid hub construction with heat treatment enhances the overall strength of the clutch, making it capable of handling increased power levels without compromising durability. The kit's components are precision-machined and assembled to exact tolerances, ensuring a perfect fit and smooth operation. This combination of materials and craftsmanship results in a clutch that not only performs under demanding conditions but also maintains a high level of reliability over time.

Installation & Fitment

The SPEC Stage 4 Clutch Kit is a bolt-on upgrade that directly replaces the factory clutch components on your 2004–2008 Subaru WRX STI with 2.0L turbocharged engines. Installation typically requires basic mechanical skills, and it is recommended to have a professional perform the clutch replacement to ensure proper setup and alignment. No cutting, drilling, or modifications are necessary, and the kit is designed for a straightforward installation process.

• Includes all necessary components for a complete upgrade, such as the pressure plate, friction disc, release bearing, and alignment tools.
• Compatible with stock flywheel or aftermarket upgrades, depending on your performance goals.

What's Included

• High-performance pressure plate
• Clutch disc with selected puck configuration
• Release bearing
• Alignment tool
• Installation instructions

Ideal For

• Performance enthusiasts seeking increased power handling
• Rally, drag, and road racers requiring a durable clutch
• Subaru WRX STI owners upgrading for high-horsepower builds
• Drivers looking for a reliable, aggressive clutch solution for daily driving and spirited use