PC Brake Disc for OE#99635140501 Front-Left Ventilated

• 99635140501. That string of numbers is not random. It is the key that unlocks the exact specification for a Porsche 911 front-left brake disc—the one that bolts onto the hub, aligns with the caliper, and stops a vehicle that was born on the Nürburgring and refined on the Autobahn. This is the OE number. The one that Porsche engineers assigned when they designed the braking system. The one that workshops look up in their catalogs when a 911 comes in for service. This disc matches that number. It fits where that number fits. And it performs to the standard that number represents.

• The front-left position matters more than many drivers realize. During hard braking, weight transfers forward and to the right—the vehicle pitches and the chassis loads the left front corner in a specific way. The left front disc sees the highest loads, the most heat, and the most aggressive pad wear of any corner. This disc was engineered for that position, with the thermal capacity to handle the demands of a 317.8mm diameter and the 28mm thickness that absorbs heat without warping. For Porsche 911 owners who drive with enthusiasm—the kind of enthusiasm that the 911 was built for—this disc delivers.

• Ventilated discs are the standard for a reason. The internal air channels act as a centrifugal pump, pulling air from the hub and expelling it through the gap between the friction plates. This disc uses that principle to manage the thermal loads that accumulate during high-speed braking. The channels are shaped to maximize airflow at the speeds that Porsches typically operate—highway cruising, track laps, mountain passes. The air flows, the heat dissipates, and the disc stays within its operating temperature range. No fade, no degradation, no surprises when the brakes are called upon.

• The 28mm thickness is not arbitrary. It provides enough thermal mass to absorb the heat of repeated stops from high speed, while remaining light enough to keep unsprung weight within acceptable limits. The dimension reflects the balance that Porsche engineers struck when they designed the braking system for the 911. This disc matches that dimension. The caliper sits where it should. The pads engage where they should. The brakes work as they should, without modification or adjustment.

• Weight shifts forward during braking. Up to 70% of the stopping force goes to the front axle. The front discs bear that load, converting kinetic energy into thermal energy with every stop. This disc handles that load through a combination of material selection and structural design. The high-carbon G3000 iron formulation resists the formation of hot spots, the localized areas of extreme temperature that can cause disc thickness variation and pedal pulsation. The ventilation channels carry heat away from the friction surfaces, preventing the temperature buildup that causes fade. The result is a disc that stops the vehicle consistently, lap after lap.

• Corrosion protection is available through multiple treatments—oiled, painted, coated, or zinc dust—each suited to different storage and operating environments. For Porsches that may be stored for extended periods or driven in coastal climates, the coated and painted variants offer enhanced protection against moisture and corrosion. The coating extends to the hub face, preventing the disc from bonding to the wheel flange and ensuring that future brake service remains straightforward.

• The precision machining of this disc achieves a surface finish that minimizes disc thickness variation and run-out. The turning and grinding operations produce a flat, parallel friction face that eliminates the pedal pulsation that plagues unevenly manufactured discs. The grinding process also creates a micro-texture that promotes rapid pad bedding, so the braking system delivers optimal performance from the first stop.

• ECE R90 certification confirms that this disc meets the braking performance standards for European aftermarket use, with documented dynamometer testing for friction coefficient, speed sensitivity, and thermal stability. The IATF 16949-certified production facility ensures consistent quality and dimensional accuracy. Whether destined for a 911 on the Autobahn, a Cayman on a mountain pass, or a Boxster in the hands of an enthusiast, this disc arrives with the traceability and documentation that professional buyers require.

• Installation requires attention to detail, as Porsche braking systems demand. The disc is designed to fit the left front position without modification, but proper torque specifications and pad bedding are essential for optimal performance. The OE designation ensures compatibility with the vehicle's ABS, stability control, and electronic parking systems, preserving the sophisticated braking logic that Porsche engineers developed.

• The OE# 99635140501 is not just a part number. It is a commitment. A commitment that this disc matches the original equipment specification in every dimension, every material, every performance parameter. And a commitment that when the driver presses the brake pedal, the vehicle responds with the authority, consistency, and control that define the Porsche experience.