Dynamite Friction 830-31097L Disc Brake Rotor - Front Left

Overview of Dynamite Friction DFC Geoperformance Rotor

The Dynamite Friction DFC Geoperformance Rotor - Drilled and Slotted (part number 830-31097L) is engineered for BMW models including the 535d, 535d xDrive, 535i, 535i xDrive, 640i, 640i Gran Coupe, 640i xDrive, 640i xDrive Gran Coupe, and ActiveHybrid 5. This vented disc brake rotor combines drilled and slotted surface features with a rust-resistant coating to maintain performance and durability under demanding conditions.

• Nominal thickness: 30 mm with discard thickness at 28.4 mm
• Directional drilled and slotted surface for improved heat dissipation
• Vented rotor design enhances cooling efficiency
• Overall diameter of 348 mm and height of 66.5 mm
• Geospec silver grey hat finish with plain disc finish
• 5 bolt holes with 16.6 mm diameter and 120 mm bolt circle diameter
• Rust resistant coating for extended rotor life

DFC Geoperformance Rotor - Drilled and Slotted Product Line

The DFC Geoperformance Rotor - Drilled and Slotted line by Dynamite Friction focuses on delivering rotors that balance performance and reliability. Featuring a directional surface with both drilled holes and slots, these rotors are designed to improve brake pad bite and reduce heat buildup. The vented rotor construction further aids in cooling, making this product line suitable for BMW vehicles requiring consistent braking performance under varied driving conditions.

Detailed Product Description

This disc brake rotor (part number 830-31097L) is specifically designed for select BMW models such as the 535i and 640i series, including xDrive and Gran Coupe variants. The rotor measures 348 mm in outside diameter and 66.5 mm in height, with a nominal thickness of 30 mm and a discard thickness of 28.4 mm, ensuring precise fitment and longevity. The vented design allows air to flow between the rotor surfaces, reducing heat and minimizing brake fade during extended use. The directional drilled and slotted surface improves water and debris evacuation, enhancing braking response in wet or challenging conditions. The rotor’s hat is finished in Geospec silver grey, complementing the plain disc finish, and it includes a rust-resistant coating to protect against corrosion over time. The 5-bolt hole pattern with a 120 mm bolt circle diameter matches the stud/lug hole configuration on compatible BMW models.

Applications and Problem Solving

• Improves braking performance on BMW 535d, 535i, and 640i models
• Reduces brake fade during aggressive or prolonged braking
• Enhances heat dissipation to prevent rotor warping
• Minimizes corrosion with rust-resistant coating
• Maintains consistent brake pad contact with directional drilled and slotted surface

Installation Notes and Tips

• Ensure rotor thickness is above discard thickness (28.4 mm) before installation
• Verify bolt hole pattern (5 holes, 16.6 mm diameter, 120 mm bolt circle) matches vehicle hub
• Clean rotor surface before installation to remove any protective coatings
• Use proper torque specifications for lug nuts to avoid rotor damage
• Inspect brake pads and calipers for wear during rotor replacement

Quality Assurance

Dynamite Friction manufactures the DFC Geoperformance Rotor - Drilled and Slotted to meet OEM specifications for fit and function. The rust-resistant coating and vented rotor design contribute to durability and consistent braking performance. While specific warranty details are not provided, this rotor is engineered to maintain reliable operation within the recommended service intervals for BMW 535d, 535i, and 640i models.