Dynamite Friction 631-31030L Disc Brake Rotor - Rear Left

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

The Dynamite Friction DFC Brake Rotor - Drilled and Slotted - Silver (part number 631-31030L) is engineered for BMW models including the 740i, 740iL, 840Ci, 850Ci, 850CSi, and 850i. This solid disc brake rotor features a directional, slotted and drilled surface designed to enhance braking performance and heat dissipation.

• Compatible with BMW 740i, 740iL, 840Ci, 850Ci, 850CSi, and 850i
• Part Number: 631-31030L
• Solid rotor with drilled and slotted surface for improved heat management
• Nominal thickness of 12 mm and discard thickness of 10.4 mm
• Zinc silver hat finish with rust-resistant coating
• Directional brake surface for optimized braking efficiency
• 5 bolt holes with 15 mm diameter and 120 mm bolt circle diameter
• Overall diameter of 324 mm and height of 61.1 mm

Product Line Details

The DFC Brake Rotor - Drilled and Slotted - Silver line by Dynamite Friction focuses on rotors that combine drilled holes and slots to provide consistent brake pad contact and effective heat dissipation. This design helps reduce brake fade and maintain performance under demanding conditions. The silver zinc coating on the rotor hat offers corrosion resistance, extending the rotor's service life.

Technical Specifications and Features

This disc brake rotor is a solid type with a nominal thickness of 12 mm and a discard thickness of 10.4 mm, ensuring reliable durability and safety margins. The rotor's surface is both drilled and slotted, which aids in removing brake dust and gases, improving braking response. The rotor features a directional surface type, which means it is designed to rotate in a specific direction for optimal performance. The zinc silver finish on the hat provides rust resistance, helping to maintain structural integrity over time. The rotor includes five bolt holes with a diameter of 15 mm and a bolt circle diameter of 120 mm, matching the stud/lug hole pattern of the specified BMW models.

Applications and Problem Solving

• Replaces worn or warped rotors on BMW 740i, 740iL, 840Ci, 850Ci, 850CSi, and 850i
• Addresses brake fade caused by excessive heat buildup during aggressive driving
• Improves braking consistency by reducing brake dust accumulation
• Helps eliminate vibration and noise associated with uneven rotor surfaces
• Prevents rust and corrosion on rotor hats for longer service life

Installation Notes and Tips

Ensure the rotor is installed with the directional surface facing the correct rotation direction as indicated on the rotor. Verify that the bolt hole pattern matches the vehicle’s hub (5 holes, 15 mm diameter, 120 mm bolt circle). Measure rotor thickness before installation to confirm it meets or exceeds the discard thickness of 10.4 mm. Clean the rotor surface to remove any protective coatings or contaminants before mounting brake pads. Proper torque specifications should be followed when tightening lug nuts to avoid rotor warping.

Quality Assurance

Dynamite Friction manufactures the 631-31030L rotor to meet OEM standards for fitment and performance on BMW 7 and 8 Series models. The rust-resistant zinc silver coating and solid rotor construction contribute to durability and reliability. While no specific warranty information is provided, the rotor is designed to maintain consistent braking performance within the specified thickness limits.