GiroDisc 2020+ BMW M3/M4 (G80/G82/G83 w/Carbon Ceramic Brakes) 2-Piece 380mm Slotted Rear Rotors

Upgrading to the GiroDisc 2020+ BMW M3/M4 (G80/G82/G83) 2-Piece 380 mm Slotted Rear Rotors—especially if your car comes with the stock carbon ceramic brakes (PCCB)—gives you several performance and practical benefits over keeping the OEM rotors:

🚗 Key Advantages

1. Better Heat Management

Slotted iron rotors dissipate heat more effectively under heavy braking compared with carbon ceramic discs in some conditions.

• The slots help release hot gases, brake dust, and debris that build up between the pad and rotor surface.
• This reduces brake fade on repeated hard stops (e.g., on a track) and keeps pedal feel more consistent.

⚖️ Lighter Unsprung Weight (Compared to OEM PCCB Steel Hat Units)

Although carbon ceramics are lighter overall, the 380 mm 2-piece GiroDisc setup saves weight compared with heavier OEM steel rotors:

• The 2-piece design uses an aluminum hat combined with an iron disc. Aluminum is much lighter than a one-piece steel rotor.
• Reducing unsprung weight improves suspension response, handling, and ride quality—especially over bumps and during quick transitions.

🛠️ Floating Design = Better Performance

Unlike fixed solid rotors, these are floating rotors:

• The rotor disc is mounted to the hat with buttons or bobbins that allow a small amount of movement.
• This helps the rotor breathe (expand and contract) under heat, which reduces the chance of warping and improves pad contact.
• Floating rotors are commonly used in motorsport because they maintain better shape and cooling during laps

🔥 Slotted Over Plain — Why It Matters

Slots cut into the rotor surface provide advantages over plain rotors:

• Evacuate heat, gas, and debris faster during braking
• Promote better pad bite when hot
• Can reduce glazing of pads
• Maintain cleaner pad surface, which helps stability in repeated braking

⛏️ More Affordable to Maintain

Compared to replacing carbon ceramic rotors:

• OEM carbon discs can cost a few times more than iron rings.
• Iron rotor rings for GiroDisc can be replaced separately when worn, lowering long-term running costs.

🧰 Fits Existing Brake Components

GiroDisc rotors are designed to work with the stock carbon ceramic hardware:

• No big modification needed for installation
• Keeps your original calipers and pads but swaps to a more robust friction surface

🧠 Practical Benefits Summarized

Benefit	What It Means for You
Higher heat tolerance	Reduced fade on road or track use
Better pad contact	Sharper pedal response
Less unsprung weight	Better handling & responsiveness
Replaceable rotor rings	Cheaper maintenance
Motorsport-inspired design	Stronger performance repeatability

🏁 Best Use Scenarios

These rear rotors are especially helpful if you:

• Do regular track days
• Drive aggressively in hilly or mountainous areas
• Want more consistent brake feel
• Want to reduce long-term replacement costs vs. carbon ceramic discs

❗ What It Doesn’t Do

For fairness, here are things this upgrade isn’t:

• Not strictly a weight-saving upgrade compared to ceramic discs — carbon ceramics are lighter overall, but this design is lighter than equivalent steel units with similar performance.
• Won’t improve braking power by itself unless paired with pads suited for the rotor surface.

🧩 Pairing Tip

If you upgrade rotors, consider matching brake pads:

• Track-oriented pads work better with iron slotted rotors than street OEM pads.
• Good pad choice improves bite, heat resistance, and wear life.

GiroDisc 2020+ BMW M3/M4 (G80/G82/G83 w/Carbon Ceramic Brakes) 2-Piece 380mm Slotted Rear Rotors