Name: HKS CARBON BRACE ADVANCED CHASSIS TUNING FOR GR86/BRZ GEN1 83001-AT004
Availability: InStock

Description

Front Rear

The HKS Carbon Brace fundamentally redefines chassis reinforcement, moving beyond simple rigidity to deliver a transformative driving experience. Engineered in collaboration with GRAPHITE DESIGN, a leading golf shaft manufacturer, it utilizes high-performance carbon fiber technology to provide exceptional torsional strength while introducing precisely tuned flexibility. This unique approach absorbs harsh vibrations and sharp impacts, eliminating the unpleasant stiffness associated with conventional metal braces and resulting in a smoother, more refined, and controllable car.

Product Highlights

🔄 Coexistence of Strength & “Flexibility”
Developed with GRAPHITE DESIGN, this brace uses a high-quality carbon shaft to achieve a breakthrough balance. It provides over 150% more torsional strength than stock to stabilize handling, while reducing bending load by 30% to absorb road vibrations. This dual-action performance creates a uniquely sophisticated ride quality.

🏎️ Circuit-Developed for Real-World Performance
Specifications were finalized through extensive testing at Fuji Speedway on both the GR86 (ZN8) and BR8 (ZD8). HKS engineers targeted the perfect balance that improves limit-handling predictability and tire contact without compromising daily comfort, moving beyond the “dry” or “rough” stock feel.

⚙️ Complete Front & Rear Reinforcement System
The kit is a comprehensive solution: it replaces the stock front steel brace and adds new connecting bars for both the front and rear. This ensures a balanced improvement in chassis behavior, preventing the disconnected feel that can come from reinforcing only one end of the car.

✨ Unified Aesthetic & Premium Material
The carbon weave direction is intentionally aligned with other HKS carbon products, creating a cohesive, high-end look within the engine bay. It replaces the utilitarian stock component with a piece that is both functionally and visually superior.

■ Fitment/Installation Information

Engine model	FA24
year model	21/10 –
remarks	Checked on SZ 18-inch MT

Technical Specifications

Product Name: Carbon Brace
Model Code: 83001-AT004
Compatibility: Toyota GR86 / Subaru BRZ (ZN8/ZD8, FA24, October 2021+)
Material: High-strength CFRP (Carbon Fiber Reinforced Polymer) shaft by GRAPHITE DESIGN.
Function: Front brace replacement + additional front and rear connecting bars.
Key Performance Metrics:
- Torsional Strength: Increased by 150% or more vs. stock.
- Bending Load: Reduced to less than 70% vs. stock.
Core Benefit: Absorbs unpleasant vibrations and sudden inputs while reducing body twist.

■Configuration diagram

Performance Philosophy

Goal: To transform the chassis feel from taut and occasionally harsh to smooth, linear, and high-quality. It seeks to improve both driving performance and ride comfort simultaneously—goals often at odds with traditional braces.
Focus: Enhancing the “texture” of the drive. It makes the car more comfortable and refined on the street while making it more stable, predictable, and easier to control at the limit on track. The driver gains a better sense of what all four tires are doing.

[CFRP pipe lamination image]

■ Seeking the unique flexibility of carbon (twisting and bending)

[About twisting]

By increasing the torsional strength by 150% or more compared to the original brace bar, twisting of the body is reduced, allowing the suspension to move more accurately.
This allows the dampers to instantly respond to even the slightest movements, resulting in precise handling.
In addition, since the torque rises quadratically with the angle, when cornering, the required amount of load is generated when needed, making it possible to stabilize driving.

[About bending]

Regarding the bending characteristics, the unique flexibility of carbon is utilized to reduce the bending load to less than 70% compared to the original brace bar, which absorbs unpleasant vibrations and sudden inputs and contributes greatly to improving the “texture.”

Installation & Tuning Notes

🔧 Professional Installation Recommended
For optimal performance and safety, installation by a professional shop is recommended to ensure proper fitment and torque specifications.
⚖️ Understanding the Feel
The steering feel will become smoother and more fluid than stock. Drivers accustomed to a very direct, high-vibration feedback may notice this change, but it is a result of the elimination of harshness, not a loss of communication. The behavior becomes more progressive and forgiving.
🔄 Front & Rear Balance is Key
Testing showed that installing only the front section could create a perceived imbalance, making the rear feel less planted. For the intended effect—a harmonious improvement in ground contact and linear behavior—the complete front and rear kit is essential.