GiroDisc Rear Brake Rotor Rings – Porsche 991 Cup / GT4 Clubsport – Factory PFC Hats

Description

GiroDisc Rear Brake Rotor Rings – Porsche 991 GT3 Cup & GT4 Clubsport

Upgrade the rear brake rotors on your Porsche 991 GT3 Cup or GT4 Clubsport with GiroDisc D2-370 slotted replacement rings, designed specifically for the original Porsche Motorsport / Performance Friction (PFC) rotor hats.

These 380 × 30mm rear rotor rings directly replace the factory PFC friction rings while allowing you to retain the existing aluminum center hats and compatible tooth-drive retaining hardware.

GiroDisc’s upgraded 72-vane cooling design, compared with the original 48-vane PFC rings, provides an alternative for race teams looking to improve rotor durability and longevity without purchasing complete rotor assemblies.

GiroDisc Part Number: D2-370
Rotor Size: 380mm × 30mm
Sold as a pair – left and right rear rings
Factory Porsche/PFC hats required – not included

Direct Replacement for Factory Porsche/PFC Rear Rings

The GiroDisc D2-370 is designed as a direct replacement for the factory rear friction rings used on compatible Porsche Cup and Clubsport brake systems.

These rings replace:

• PFC 380.30.0047.451 – Left Rear
• PFC 380.30.0047.461 – Right Rear

The factory-compatible tooth-drive arrangement allows the GiroDisc rings to mount to the existing Porsche/PFC aluminum hats without requiring new center hats or a complete GiroDisc rotor conversion.

Upgraded 72-Vane Cooling Design

GiroDisc developed these replacement rings with an increased internal cooling-vane count.

GiroDisc D2-370: 72 cooling vanes
Original PFC rear rotor: 48 cooling vanes

The 72-vane construction is designed to improve rotor durability and service life during the repeated high-temperature braking cycles experienced in competition.

The slotted friction surface is suited to demanding track and racing applications.

Retain Your Factory Rotor Hats

One of the biggest advantages of the D2-370 is that you can continue using your existing Porsche Motorsport / PFC rotor hats.

When the original friction rings reach their service limit, the worn rings can be removed and replaced with GiroDisc D2-370 rings, provided the factory hats and retaining hardware remain serviceable.

This allows you to upgrade the friction rings without the additional expense of purchasing complete rotor assemblies.

Porsche 991 GT3 Cup & GT4 Clubsport Applications

Designed for compatible factory Porsche/PFC rear brake rotor assemblies on:

• Porsche 991 GT3 Cup
• Porsche 981 Cayman GT4 Clubsport
• Porsche 718 Cayman GT4 Clubsport

Fitment requires the original-style Porsche/PFC rear rotor hats and tooth-drive mounting system.

Important – Factory Porsche/PFC Hats vs. GiroDisc Hats

GiroDisc offers two different rear replacement-ring designs for these applications.

D2-370 – Factory Porsche/PFC Hats

Designed for customers retaining their original Porsche Motorsport / PFC aluminum rotor hats.

D2-238 – GiroDisc Hats

Designed for customers who already have complete GiroDisc rear rotor assemblies with GiroDisc-specific aluminum hats.

These two replacement-ring designs are not interchangeable.

If your car uses factory Porsche/PFC rotor hats, select D2-370.

If your car uses GiroDisc rotor hats, select D2-238 instead.

Specifications

• Manufacturer: GiroDisc
• Part Number: D2-370
• Application: Porsche 991 GT3 Cup / GT4 Clubsport
• Axle: Rear
• Diameter: 380mm
• Thickness: 30mm
• Minimum Thickness: 28mm
• Friction Surface: Slotted
• Cooling Vanes: 72
• Original PFC Cooling Vanes: 48
• Mounting: Factory-compatible tooth-drive system
• Required Hats: Factory Porsche/PFC
• Quantity: Pair
• Hardware: Not included

Features

• Direct replacement for factory Porsche/PFC rear friction rings
• Fits Porsche 991 GT3 Cup and compatible GT4 Clubsport applications
• 380 × 30mm
• 72-vane cooling design
• Slotted racing friction surface
• Reuses serviceable factory Porsche/PFC aluminum hats
• Compatible with original tooth-drive mounting arrangement
• No need to purchase complete GiroDisc rotor assemblies
• Designed for demanding track and competition use
• Sold as a left and right rear pair

Important Installation Note

These D2-370 rings are designed for factory Porsche/PFC rotor hats, not GiroDisc hats.

New mounting hardware is not included. Inspect the existing hats and retaining hardware for wear or damage and follow the applicable Porsche/PFC assembly and service requirements.

If you are unsure which rotor hats are installed on your car, contact Demon Speed before ordering.