Dynamite Friction 633-31121L Disc Brake Rotor - Front Left

Overview of the DFC Brake Rotor - Drilled and Slotted - Black

The Dynamite Friction DFC Brake Rotor - Drilled and Slotted - Black (part number 633-31121L) is engineered for BMW models including the 228i, 328i, 328i xDrive, 330e, and 428i. This vented disc brake rotor features a directional, slotted and drilled surface designed to enhance braking performance and heat dissipation.

• Nominal thickness: 24 mm with a discard thickness of 22.4 mm
• Outside diameter: 330 mm
• Vented rotor design for improved cooling
• Directional slotted and drilled surface for debris removal and heat management
• Zinc black hat finish with rust-resistant coating
• 5 bolt holes with 16.6 mm diameter and 120 mm bolt circle diameter
• Center hole diameter: 79 mm
• Height: 73.2 mm

Detailed Product Description

This DFC Brake Rotor - Drilled and Slotted - Black is specifically designed to meet the braking demands of select BMW vehicles such as the 228i, 328i, 328i xDrive, 330e, and 428i. The rotor’s vented construction allows for efficient heat dissipation during braking, reducing the risk of brake fade under heavy use. The directional slotted and drilled surface helps to channel away water, dust, and gases, maintaining consistent brake pad contact and improving overall stopping power.

The rotor’s zinc black hat finish provides corrosion resistance, extending the rotor’s service life. With a nominal thickness of 24 mm and a discard thickness of 22.4 mm, this rotor ensures reliable performance within BMW’s specified tolerances. The 5-bolt hole pattern with a 120 mm bolt circle diameter matches the factory specifications for secure fitment.

About the DFC Brake Rotor - Drilled and Slotted - Black Product Line

The DFC Brake Rotor - Drilled and Slotted - Black line from Dynamite Friction offers rotors designed with enhanced surface features such as drilled holes and slots to improve braking efficiency and heat management. This product line focuses on vented rotors with corrosion-resistant finishes, suitable for performance-oriented and daily driving applications. The black zinc hat finish adds durability against rust, making these rotors a practical choice for BMW vehicles requiring reliable braking components.

Common Applications and Problem Solving

• Replacement for worn or warped rotors on BMW 228i, 328i, 328i xDrive, 330e, and 428i
• Improves heat dissipation to reduce brake fade during aggressive driving or towing
• Slotted and drilled surface helps prevent brake pad glazing and maintains consistent braking
• Rust-resistant coating addresses corrosion issues common in humid or salty environments
• Directional design optimizes braking performance and rotor longevity

Installation Notes and Tips

Ensure the rotor thickness is above the discard thickness of 22.4 mm before installation. Clean the rotor surface to remove any protective coatings or residues prior to mounting. Verify the 5-bolt hole pattern and 120 mm bolt circle diameter match the vehicle hub. Proper torque specifications should be followed to avoid rotor warping. It is recommended to replace brake pads when installing new rotors to ensure optimal braking performance.

Quality Assurance

Dynamite Friction manufactures the 633-31121L rotor to meet OEM specifications for fitment and performance on BMW 228i, 328i, 328i xDrive, 330e, and 428i models. The rust-resistant zinc black hat finish and vented rotor design contribute to durability and consistent braking. Warranty information is available through the manufacturer and should be consulted for coverage details.