HKS Hipermax S Coilovers for 2015-2021 Subaru WRX / STI

HKS Hypermax S Coilovers – Subaru WRX / STI

The HKS Hypermax S Coilovers are a precision-engineered suspension system developed to significantly enhance chassis control, damping response, and overall vehicle dynamics on the Subaru WRX and STI. Designed using motorsports-derived technology, this system delivers high-level performance for aggressive street driving and track use without compromising ride quality.

Backed by decades of HKS suspension and racing development, the Hypermax S features a mono-tube damper architecture combined with advanced valve control to maintain consistent damping under high load and temperature conditions. The result is improved steering response, reduced body roll, and superior road feedback across a wide range of driving scenarios.

Each kit arrives fully assembled with upper mounts and includes all required adjustment tools, allowing for precise ride height and damping tuning to match driver preference, tire setup, and driving environment.

Key Technologies & Features

• Dual Preload Valve System (Dual PVS)
  Independently controls low- and high-speed damping to eliminate excessive damping force during rapid suspension movement, maintaining ride compliance while preserving stability under aggressive driving.

• Wide-Range 30-Way Damping Adjustment
  Redesigned needle jet geometry provides a broader, more usable adjustment range, enabling fine-tuned damping control for street, canyon, or track applications.

• Optimized Bump Stop Geometry
  Redesigned bump stop rubber reduces sudden load transfer and body roll while maintaining compliance—delivering controlled suspension travel without harsh bottoming.

• Low-Friction Internal Components
  Advanced tribology reduces friction between internal damper components, improving response speed, durability, and consistency under sustained performance driving.

• Mono-tube damper design for improved heat dissipation

• Independent ride height adjustment via shock-body length

• High-performance damper oil engineered for thermal stability

• PNE-coated shock bodies for corrosion resistance

• CNC aluminum brackets for strength and weight reduction

• Rubber upper mounts for controlled NVH without sacrificing precision

Technical Specifications

• Spring Rates:
  Front: 9.0 kg/mm
  Rear: 7.0 kg/mm

• Spring Length:
  Front: 220mm (straight barrel)
  Rear: 170mm (straight barrel)