D1-185 Girodisc Subaru WRX STI (2018+) Front Replacement Rings

Bring your WRX STI’s braking system back to full strength with Girodisc D1-185 340 mm front replacement rings. These high-performance rings bolt directly to your existing Girodisc aluminum hats using the included floating hardware kit. Each ring is CNC-machined from Girodisc’s proprietary high-carbon iron alloy for superior thermal control, consistent bite, and fade-resistant performance in street or track conditions.
Vehicle Fitment
Compatible with:
• Subaru WRX STI (2018 and newer, Brembo 6-piston front calipers)
Note: Designed for Girodisc 340 mm two-piece front rotor systems. Not compatible with OEM one-piece rotors or earlier 4-piston STI setups.
Features
• Sold as a left/right pair with complete floating hardware kit
• Direct replacements for Girodisc 340 mm two-piece front rotors
• High-carbon iron construction for stable performance at high temperatures
• Directional curved vanes improve airflow and cooling efficiency
• Maintains OEM brake bias and ABS calibration
• Precision-balanced for quiet, vibration-free operation
• Designed exclusively for Girodisc aluminum hats
Specifications
• Diameter: 340 mm
• Position: Front
• Material: High-carbon cast iron
• Mount type: Floating two-piece system
• Includes: Two rotor rings and new hardware kit
• Sold/priced per pair
Girodisc D1-185 Subaru WRX STI (2018+) Front Replacement Ring FAQs
Do these fit directly on the OEM Subaru rotor hats? No. The D1-185 rings are specific to Girodisc aluminum hats and will not fit factory one-piece rotors.
What torque should I use for the drive-pin bolts? Girodisc recommends 12 ft-lbs (16 Nm) with blue Loctite applied to each fastener; safety-wire if desired for track use.
Are these compatible with aftermarket pads like Ferodo DS2500 or Hawk DTC-60? Yes. These rings work with all STI-fit pad compounds and perform best after a proper bedding cycle.
How long do these typically last under heavy track use? Track-driven STIs see roughly 25–35 hours of hard use per set; street cars often exceed 50,000 miles depending on pad material and driving style.
Enhance your Subaru WRX STI with Girodisc D1-185 340 mm front replacement rings — precision-engineered for heat resistance, longevity, and confidence lap after lap.