• ACT Heavy Duty Race Rigid 4 Pad Clutch Kit with Monoloc | Subaru WRX/STi (04-21) (SB10-HDR4)
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ACT Heavy Duty Race Rigid 4 Pad Clutch Kit with Monoloc | Subaru WRX/STi (04-21) (SB10-HDR4)

ACT Heavy Duty Race Rigid 4 Pad Clutch Kit with Monoloc | Subaru WRX/STi (04-21) (SB10-HDR4)

SB10-HDR4

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$781.00 USD
$964.00 USD $781.00 USD
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The ACT Heavy Duty Race Rigid 4 Pad Clutch Kit with Monoloc is a high-performance clutch assembly designed for Subaru WRX and STI models from 2004 to 2021. This kit features ACT's most popular Heavy Duty pressure plate, which utilizes an exclusive diaphragm design to increase clamp load, reduce deflection, and extend clutch life. The pressure plates undergo a four-stage heat-treating process to ensure durability and consistent performance under demanding conditions. The 4-pad rigid race discs are constructed with high-quality materials to deliver reliable grip and precise engagement, making this clutch kit suitable for aggressive driving and racing applications. Its robust design enhances power transfer and pedal feel, providing enthusiasts with a durable upgrade that withstands high torque loads.

This clutch kit is compatible with Subaru WRX and STI models from 2004 through 2021, including various engine configurations. It is intended for use in street, track, or racing environments where increased clamping force and durability are required. The installation involves a direct bolt-on replacement for the stock clutch components, ensuring a straightforward upgrade process. The kit includes the heavy-duty pressure plate, four-pad rigid race disc, and Monoloc release bearing, offering a complete solution for high-performance clutch needs. Suitable for both daily driving and competitive motorsport, this clutch assembly provides improved engagement, longevity, and consistent performance under high-stress conditions.

Overview

ACT 2004-2021 Subaru WRX STI / Legacy Spec.B HD-M/Race Rigid 4 Pad Clutch Kit

SB10-HDR4 kit features ACT's most popular Heavy Duty pressure plate. ACT Heavy Duty pressure plates use exclusive diaphragm design to increase clamp load, reduce deflection and maximize clutch life. All diaphragms endure a four-stage, heat-treating process for unparalleled performance.

ACT pressure plates have precision cover stampings to provide rigidity and consistency. ACT's 4-pad rigid race discs are made with high quality, ceramic friction materials. The chrome-moly hub is heat-treated for strength and durability. The lightweight, rigid design allows for quicker shifts and smooth, trouble-free service. With the 4-pad rigid race disc engagement is harsher, but shifting is faster. The 4-pad rigid race disc is well-suited for the smaller disc sizes in smaller engines.

Monoloc is a one-piece, direct replacement or upgrade to the standard, two-piece wedge collar and wire ring featured in pull-type clutches. The spring tension of the segmented retaining ring is carefully calculated and tested for optimal performance. It provides uniform loading on the bearing and pressure plate to assure proper alignment, regardless of driver influence or vehicle modifications. Monoloc's hardened chrome-moly steel construction will provide years of service.

Features

  • Torque Capacity (ft/lbs.): 660
  • Light to moderate pedal effort, aggressive engagement, increased gear rattle, confidence during hard shifts
  • Moderate friction life, extended by ACT's exclusive diaphragm design, dramatic improvement in release mechanism life, rigid design may increase spline wear
  • Carefully engineered, precisely assembled, accurately balanced, uses select ceramic friction materials for high heat tolerance and maximum performance, major improvement in release mechanism
  • Recommended for race use only
  • 100% clamp load tested and dynamically computer balanced for smooth high RPM reliability, includes ACT's patented Monoloc

Applications

  • 2004-2021 Subaru WRX STI
  • 2007-2009 Subaru Legacy GT spec.B (see * below)
  • *240mm
  • *6 speed applications only
  • *Must use ACT or factory flywheel for the 2004 and newer WRX STi

What's in the box?

  • 4240018 - 4 Pad Rigid Race Disc
  • AT90 - Alignment Tool
  • PB1004 - Pilot Bearing
  • RB601 - Release Bearing
  • SB019 - P/PL-M Heavy Duty Pressure Plate
  • Installation Instructions!

Specifications

  • Description: HD-M/Race Rigid 4 Pad
  • Torque Capacity (ft/lbs.): 660
  • Torque Capacity Over OE: 86%
  • Disc Type: Race Disc
  • Spline Count: 24
  • Spline Size (in.): 1
  • Disc Diameter (in.): 9.4
  • Disc Diameter (mm.): 240
  • Pressure Plate Type: Heavy Duty
  • Product Weight (lbs.): 15.9
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