AP Racing Brakes

AP Racing Radi-CAL R2 Racing Brake Fluid Outstanding Performance in High-Heat Braking Applications AP Radi-CAL R2 racing brake fluid was developed for the extreme abuse of heavy race cars competing in endurance events. AP Racing Radi-CAL R2 fluid has a dry boiling point of 593º F (312º C), and was developed for racing applications where high brake temperatures are common (e.g., when using carbon discs) and very high temperature brake fluid performance is required. Before using AP Racing Radi-CAL R2 fluid, any existing brake fluid should be drained completely from the car's brake system. The system should be thoroughly purged with new R2 and can then be filled completely with fresh R2 fluid. AP Racing Radi-Cal R2 Brake Fluid Details: Manufacturer: AP Racing Manufacturer part number: AP-CP5600 R2 fluid conforms to and exceeds DOT4 specifications, but should not be used with components made from magnesium Dry Boiling Point: 593º F / 312º C Wet Boiling Point: 383º F / 195º C Bottle Size: 500 ml (16.9 fl. oz.)

AP Racing Radi-CAL R4 Racing Brake Fluid Among the Highest Dry Boilings Point On The Market Today AP Racing Radi-CAL R4 racing brake fluid has an ultra-high typical dry boiling point, at 644º F / 340º C. Radi-CAL R4 racing brake fluid has been designed to perform better than any other product at the extremes of heavy-duty braking in top levels of professional racing. AP Racing Radi-CAL R4 has outstanding resistance to vapor lock and pedal fade under the most exacting conditions. A higher vapor lock point means a firmer brake pedal at the extremes of brake temperatures. Enhanced lubricity means R4 is a better lubricant than other market-leading racing brake fluids. This helps extend the life of the metal moving parts in your brake system while increasing system efficiency. Radi-CAL R4 can be mixed with other DOT 3 and DOT 4 racing brake fluid, although for maximum performance your braking system should be thoroughly purged with R4 fluid. AP Racing Radi-Cal Pro R4 Brake Fluid Details: Manufacturer: AP Racing Manufacturer part number: AP-CP7005 DOT rating: DOT 4 Dry Boiling Point: 644º F / 340º C Wet Boiling Point: 383º F / 195º C Bottle Size: 500 ml (16.9 fl. oz.)

AP Racing Radi-CAL R1 Racing Brake Fluid Brake Fluid Suitable for All Forms of Motorsport AP Racing Radi-CAL R1 DOT 4 racing brake fluid was developed for road cars being used in events such as autocross and track days, where drivers need brake fluid with a higher boiling point than that of standard OEM brake fluid. While AP Racing Radi-CAL R1 fluid has the lowest dry boiling point of AP Racing's racing brake fluid lineup at 516º F (269º C), it far exceeds that of ordinary DOT 4 brake fluid. It was developed for applications needing more heat resistance than typical OEM brake fluid. AP Racing Radi-CAL R1 Brake Fluid Details: Manufacturer: AP Racing Conforms to FMVSS 116 DOT3 specification Manufacturer part number: AP-CP7551 New Dry Boiling Point: 516º F / 269º C Wet Boiling Point: 284º F / 140º C Bottle Size: 500 ml (16.9 fl. oz.)

AP Racing 380x34mm Replacement J Hook Rotor Rings Replacement Disc Only For AP Racing 13.01.20017 Rotor discs and installation hardware only. Center hat excluded. Fits The Following Cars (w/ OEM Iron Rotors) Porsche 991 GT3 (Front) Porsche 991 GT3RS (Front) Porsche 981 GT4 (Front) AP Racing by Essex 2-piece Competition J Hook front disc pair for 981 GT4, 991.1 & 991.2 GT3 & GT3 RS with iron discs 380mm x 34mm (14.96" x 1.34") 72 Vane, D66 Huge increase in airflow, cooling capacity, and durability vs. OEM discs Saves 2 lbs. unsprung weight per side vs. OEM iron discs Designed for: club racing, time trial, auto-x, HPDE Works with OEM calipers, no modifications required Ultralight, fully floating, anodized billet aluminum hat with float control/anti-rattle clips Sold/priced per pair of rotor rings (including hardware). AP Racing J Hook Brake Rotors – The Gold Standard in Track Day & Racing Performance Engineered for professional motorsport, HPDE, and dedicated track day use, AP Racing’s J Hook Brake Rotors deliver uncompromising performance, thermal stability, and consistent braking power. These two-piece, floating rotors are built to handle the extreme demands of road racing, with design features derived from over 50 years of elite competition—including Formula 1, NASCAR, and IMSA. Unlike conventional one-piece rotors, AP Racing’s two-piece floating design features a billet aluminum hat mated to a cast iron disc via precision-engineered bobbins. This setup allows for controlled radial expansion under high heat, minimizing distortion and coning. The result? More even pad wear, a firmer pedal feel, and longer component life, even during extended lapping sessions or endurance racing. Floating hardware includes anti-knockback spring clips that reduce piston retraction while eliminating common NVH issues like rattling. Why Choose AP Racing J Hook Rotors? Advanced Cooling, Superior Bite, Unmatched Durability At the heart of every rotor is AP Racing’s proprietary high-carbon iron alloy, developed to withstand repeated thermal cycling without cracking or warping. Internally, directional vanes—far superior to OEM pillar or straight vane designs—maximize airflow and cooling. With 60 to 84 vanes per rotor, AP Racing achieves faster heat evacuation, reduced brake fade, and a more consistent friction surface. These rotors are left/right-specific for optimal airflow and balance. The exclusive J Hook slot pattern offers enhanced initial bite and promotes uniform heat distribution across the rotor face, reducing pad deposits and vibration. Unlike drilled rotors or straight-slot competitors, the J Hook design provides cleaner pad transfer during bed-in and superior modulation under braking—ideal for serious drivers who demand feedback and control. Yes, you might hear a little more whirr, but you’ll gain the stopping power, consistency, and longevity your lap times demand. Premium Components, Affordable Performance The rotor hats are CNC-machined from 6061-T6 billet aluminum and hard anodized for strength and heat resistance. Scalloped edges under the hat further assist heat dissipation. All hardware is U.S.-made to AP Racing spec, the same quality found on pro-level racing platforms. And while these rotors are race-proven, they’re also surprisingly cost-effective to replace. Don’t settle for cheap rotors that crack after a weekend—AP’s J Hook rings offer better durability and real long-term value. Fewer replacements mean more track time, less downtime, and peace of mind knowing you're running the best. Used by Champions. Trusted by Experts. From endurance racers to HPDE enthusiasts, AP Racing brake rotors are trusted worldwide for their reliability, longevity, and performance under pressure. Whether you're shaving seconds off your lap time or building a dedicated track car, the J Hook delivers a professional-grade solution that won’t let you down. AP Racing J Hook Brake Rotors for Auto Racing, Track Days & HPDE Why Rotor Design Matters: Heat Expansion and Floating Technology As with most metals, iron brake discs expand significantly under heat. When temperatures rise, the disc grows radially—expanding in both diameter and circumference. Traditional one-piece rotors struggle to accommodate this natural expansion. As the outer edge pulls away from the center under heat stress, it creates a condition called “coning”—a distortion that compromises pad-to-rotor contact. This distortion can lead to uneven pad wear, brake tapering, and an inconsistent, long brake pedal. AP Racing two-piece floating brake rotors are purpose-built to eliminate these issues. Engineered with “float” built into the disc or hat assembly, these rotors feature oblong-shaped mounting holes that allow the hardware to slide as the disc heats up. This flexibility ensures the disc runs true within the caliper under high-temperature loads, effectively reducing distortion, minimizing pad taper and stress cracks, and promoting longer component life. Custom Mounting Hardware & Anti-Knockback Spring Clips AP Racing rotors utilize application-specific, U.S.-made mounting hardware—not generic bolts. These premium components are the exact parts used in AP’s professional motorsport products, engineered to withstand the rigors of competitive racing. To manage lateral disc motion that can push caliper pistons backward (known as knockback), AP Racing integrates anti-knockback spring clips on alternating bobbins—five on a ten-bolt setup, six on a twelve-bolt disc. These clips keep the aluminum hat and iron disc ring properly aligned while still allowing for radial float. Bonus: they eliminate annoying rattles and vibrations, ensuring a quieter, more refined braking experience. High-Performance Hat Design for Heat Isolation The disc hats in AP Racing’s two-piece floating rotors are CNC-machined from 6061-T6 billet aluminum and finished with a hard anodized coating. This high-strength aluminum alloy was selected for its ability to maintain structural integrity even at elevated temperatures. AP adds scalloped channels beneath the hat to further encourage airflow and heat evacuation from the outer disc face, minimizing thermal transfer to hubs and wheel bearings—helping reduce maintenance costs on these expensive components. Internal Vane Engineering: Airflow Optimization & Thermal Stability AP Racing’s internal vane design sets them apart from OEM and most aftermarket competitors. While many factory brake discs use non-directional pillar vanes (low-cost and NVH-focused), AP Racing rotors use directional vanes engineered for maximum airflow. These rotors are side-specific—meaning you’ll receive a unique left and right disc in each set—ensuring optimized cooling through strategic vane orientation and shape. Beyond that, AP Racing rotors feature a superior vane count, typically ranging from 60 to 84 vanes, compared to 30–48 in most aftermarket rotors. After extensive CFD and thermal analysis, this high vane count was proven to: Increase airspeed and thermal transfer Reduce recirculation and deflection at the disc face Minimize coning, cracking, and brake fade Deliver more even pad contact and extended rotor life J Hook Slot Pattern: Exclusive to AP Racing Slots and drill holes may improve initial bite, but they also introduce “cool spots” in the rotor face—areas of uneven heating that can lead to stress risers, cracks, and pad vibration. OEM rotors often avoid this by leaving the disc face blank, but that compromises bite and brake feel. AP Racing’s patented J Hook design, developed through rigorous R&D, solves this problem. The hooks are meticulously spaced around the disc’s circumference and from hat to edge, forming a continuous distortion path that ensures even heat distribution. This encourages uniform pad deposits during bed-in, helps reduce judder and cracking, and improves consistency under repeated high-load braking. In addition, the J Hook slots provide more leading edges for pads to grip than traditional curved slots or blank rotors. While this might generate a mild whirring sound during braking, the benefits—more bite, cleaner bedding, better pedal feel—make it the top choice for committed racers and serious track day drivers. Metallurgy Backed by 50+ Years of Motorsport Leadership AP Racing's reputation is built on performance, and their proprietary iron alloy used in J Hook rotors is no exception. Drawing from over five decades of elite motorsport experience, including 750+ Formula 1 wins and widespread use across NASCAR, AP’s engineers have developed a disc alloy that excels under sustained racing temperatures and stress. Where OEM discs focus on affordability and mass production, AP Racing’s J Hook rotors are purpose-built for motorsport durability and heat resistance. Affordable Replacement Cost: Serious Value for Serious Drivers Even the best brake rotors are consumables. When you drive hard—especially at the track—your discs will eventually wear out. That’s why AP Racing designed their replacement iron rings to be cost-effective, allowing you to replace worn parts without breaking the bank. Compare that to constantly buying cheap $150 rotors every weekend—rotors that can't handle the heat and need to be swapped frequently. With AP Racing’s J Hook rotors, you get longer service intervals, less downtime, and better performance over time, making them an incredibly smart long-term investment. Proven on Track. Trusted by Champions. Top-tier racing teams rely on AP Racing J Hook rotors for one reason: they perform under pressure. Whether you're running time trials, attending HPDE events, or competing in wheel-to-wheel racing, these rotors offer professional-grade reliability, safety, and performance. Bedding and Preparation of AP Racing J Hook Discs Properly preparing your new brake discs before heavy use is extremely important. The goal of bedding-in your brake pads and discs is to mate them together properly and prepare them for heavy use.  When prepared properly, or bed-in, your pads will transfer a thin layer of material to the disc face (transfer layer).  The pads in your caliper will then actually ride on that thin layer of pad material you’ve put down on the rotor, rather than rubbing directly on the iron rotor face.  A good transfer layer is going to give you superior brake pedal feel, less noise, superior pad wear, and lower the chances of cracking your discs. Important Notes- PLEASE READ! First, make sure you are on a closed course to perform a proper bed-in.  Do NOT perform the procedure on public roads.  You need a stretch of asphalt with long straights, good visibility, and no potential obstructions.  Make sure you are in a position to safely and repeatedly attain the necessary speeds to perform the bed-in procedure.  A controlled racetrack is the best place to perform this procedure.  AP Racing and Competition Motorsport in no way suggest or condone speeding on public roads or breaking the law in your car, nor do we take responsibility for any damage or injury that occurs as a result of using our product or these procedures.  You are performing the bed-in procedure at your own risk.  During these procedures, it’s critical that you never come to a complete stop with your foot on the brake pedal.  If you have brake ducts on your car, you may want to block them off to allow your brake system to heat up easily. The procedure outlined below is a generic procedure for most types of mild race pad.  Please check your pad manufacturer’s recommended bed-in procedure. Accelerate to approximately 60mph and then decelerate down to 5 mph.  If your car has ABS, you should try to hold the brakes at a point just before ABS intervention.  Once the car slows to 5mph, immediately accelerate back up to about 60mph, and brake again to roughly 5mph.  Repeat this series of stopping and accelerating 8 to 10 times.  Again, do not come to a complete stop with your foot on the brake pedal. Cool the brake system down by cruising at 45mph+ for 5 to 10 minutes. Visually inspect your discs.  They should be a blue/grey color (instead of shiny silver), and have an even layer of pad material across and around the entire rotor face. If the AP Racing rotors don’t have a layer of pad material on them, perform another series of stops in the manner outlined above.

AP Racing Radi-CAL 380mm Competition Brake Kit Porsche 992 GT3/GT3RS (Rear) Fit The Following Cars Porsche 992 GT3  Porsche 992 GT3RS  Complete AP Racing Radi-CAL Competition Brake Kit. Fits all variants of the Porsche 992 GT3/GT3RS: Eliminates the need to remove the caliper for pad changes Retains OEM parking brake functionality Jewel-like ENP Caliper finish is incredibly durable and easy to clean Saves 18 unsprung lbs. vs. OEM iron brakes and weighs almost the same as the OEM PCCB system AP Racing Radi-CAL with durable, ventilated stainless steel pistons (no ceramic piston caps to break) with anti-knockback springs Allows for the preservation of pricey OEM brake components Huge array of brake pad options from all major pad manufacturers Fits OEM 20" wheels without spacer 380 x 32mm, 72 vane AP Racing disc fits inside popular 19" wheels Every component designed to resist the heat of extended track sessions Pistons sized properly to allow for seamless integration with OEM master cylinder and ABS system Includes pad tension kit (eliminates noise) and disc burnishing at no additional cost Designed to work with the front AP Racing Radi-Cal brake kit

AP Racing Radi-CAL 394mm Competition Brake Kit 992 GT3/GT3RS (Front) Fit The Following Cars Porsche 992 GT3  Porsche 992 GT3RS  Complete AP Racing Radi-CAL Competition Brake Kit for the Porsche 992 GT3/GT3RS (Front) May interfere with front anti-roll bar under certain conditions. Please see TSB below. Jewel-like ENP Caliper finish is incredibly durable and easy to clean Durable, ventilated stainless steel pistons (no ceramic piston caps to break) with anti-knockback springs Design eliminates the need to remove caliper for pad changes Saves 17 unsprung lbs. vs. OEM iron brakes and very close in weight to the OEM PCCB system Allows for the preservation of pricey OEM brake components Huge array of brake pad options from all major pad manufacturers 394x34mm, 84 vane AP Racing J Hook Discs Every component designed to resist the heat of extended track sessions Pistons sized properly to allow for seamless integration with OEM master cylinder and ABS system Includes pad tension kit (eliminates noise) and disc burnishing at no additional cost Designed to work with OEM rear brakes or the Ap Racing rear brake kit Includes the AP Racing pad tension kit and disc burning at no additional cost Designed to work with OEM rear brakes or the AP Racing Rear Brake Kit Porsche 992 Technical Service Bulletin ("TSB") The Porsche 992 GT3/GT3RS introduced some dramatic suspension changes vs. the 991 chassis, most notably moving from a McPherson Strut configuration to double wishbone at the front of the car.  The resulting packaging and geometry changes create some potential brake clearance issues under certain driving conditions.  With the brake lines attached to the standard front caliper inlet port contact may occur between the brake line banjo fitting and the front anti-roll bar (ARB) drop links or the ARB itself.  The interference issue is more pronounced in our CP9669 Kits due to the extremely wide calipers but can also impact our CP9661 Kits to a lesser extent. Porsche delivers these cars with the front and rear ARBs set to the middle position.  Potential interference between the brake line fitting and drop links becomes more likely to occur as: The anti-roll bar is adjusted towards the softest setting (the hole closest to the end of the bar) The steering wheel is turned towards full lock The suspension is under full droop (extended as far as possible) To address this clearance issue, AP Racing has developed the following solution: Relocate the caliper hydraulic connection from its current position to the lower bleed screw.  This requires a new Spiegler brake line of a different length with a new banjo bolt design manufactured by Spiegler. The original inlet port in the center of the AP Racing caliper will be closed off with a plug. CP9661 Kit, part# 13.01.10141/13.01.10141-ENP On our CP9661 front caliper kits in the as-delivered configuration (brake line attached to the inlet port in the middle of the caliper), interference between the drop link and the brake line fitting may occur when the ARB is adjusted to the softest setting as you approach full steering lock and full suspension droop.   If you won’t be running the ARB in the softest setting with our CP9661 kit, you should not anticipate any issues, and you should not expect any interference when the ARB is set to the medium or stiff settings.  If you do plan to run your front ARB in the softest setting, we suggest implementing our brake line relocation as described above, which will provide adequate clearance in all ARB settings. CP9669 Kit, part# 13.01.10142-ENP The wider calipers in our CP9669 kits extend further into the wheel well, which creates more potential clearance issues.  With the brake line attached to the center inlet port and the ARB set in the soft or middle settings, there may be interference between the brake line banjo fitting or the caliper body with both the ARB drop links or the ARB itself. With the brake line relocated to the lower bleed screw port, the CP9669 calipers have adequate clearance with the front anti-roll bar end links when they are set in the middle or stiffest positions.  The caliper will not clear the front anti-roll bar adjusted to its softest setting, so the ARB cannot be run in that setting.  Under full droop and full lock, the end of the anti-roll bar itself may make minor contact with the inlet port plug, but the likelihood of putting the components in those positions under normal driving conditions is very low.

AP Racing Radi-CAL 394mm Competition Brake Kit for Porsche GT4 (Front) Fit The Following Cars Porsche 981/718 GT4 (PCCB and Iron Rotors) Complete front AP Racing Radi-CAL Competition Brake Kit for the Porsche Cayman 981/718 GT4. Features AP Racing Radi-CAL 9669 calipers for extreme durability! Clears many popular 19" and 20" track wheels Durable, ventilated stainless steel pistons (no ceramic piston caps to break) with anti-knockback springs Design eliminates the need to remove caliper for pad changes Saves 10 unsprung lbs. vs. OEM iron brakes and very close in weight to the OEM PCCB system Allows for the preservation of pricey OEM brake components Huge array of brake pad options from all major pad manufacturers 394x34mm, 84 vane AP Racing J Hook Discs Every component designed to resist the heat of extended track sessions Pistons sized properly to allow for seamless integration with OEM master cylinder and ABS system Includes the AP Racing pad tension kit and disc burning at no additional cost Designed to work with OEM rear brakes or the AP Racing Rear Brake Kit

AP Racing Radi-CAL 380mm Competition Brake Kit GT4RS (Rear) Fit The Following Cars Porsche 718/982 GT4RS (PCCB and Iron Rotors) Complete rear AP Racing Radi-CAL Competition Brake Kit. Fits all variants of the Porsche 718/982 GT4RS. Eliminates the need to remove the caliper for pad changes Retains OEM parking brake functionality Saves 18 unsprung lbs. vs. OEM iron brakes and weighs almost the same as the OEM PCCB system Jewel-like ENP caliper finish is incredibly durable and easy to clean AP Racing Radi-CAL with durable, ventilated stainless steel pistons (no ceramic piston caps to break) with anti-knockback springs Allows for the preservation of pricey OEM brake components Huge array of brake pad options from all major pad manufacturers Fits OEM 20" wheels without spacer 380x32mm, 72 vane AP Racing disc fits inside popular 19" wheels Every component designed to resist the heat of extended track sessions Pistons sized properly to allow for seamless integration with OEM master cylinder and ABS system Includes pad tension kit (eliminates noise) and disc burning at no additional cost Designed to work with Ap Racing front Brake Kit

AP Racing Radi-CAL 380mm Competition Brake Kit GT4 (Rear) Fit The Following Cars Porsche 981 GT4 (PCCB and Iron Rotors)  Porsche 718 GT4 (PCCB and Iron Rotors) Complete rear AP Racing Radi-CAL Competition Brake Kit. Fits all variants of the Porsche 718/981 GT4. Eliminates the need to remove the caliper for pad changes Retains OEM parking brake functionality Saves 18 unsprung lbs. vs. OEM iron brakes and weighs almost the same as the OEM PCCB system Jewel-like ENP caliper finish is incredibly durable and easy to clean AP Racing Radi-CAL with durable, ventilated stainless steel pistons (no ceramic piston caps to break) with anti-knockback springs Allows for the preservation of pricey OEM brake components Huge array of brake pad options from all major pad manufacturers Fits OEM 20" wheels without spacer 380x32mm, 72 vane AP Racing disc fits inside popular 19" wheels Every component designed to resist the heat of extended track sessions Pistons sized properly to allow for seamless integration with OEM master cylinder and ABS system Includes pad tension kit (eliminates noise) and disc burning at no additional cost Designed to work with Ap Racing front Brake Kit

AP Racing Radi-CAL 380mm Competition Brake Kit (Rear) Fit The Following Cars Porsche 991 GT2RS  Porsche 991 GT3  Porsche 991 GT3RS  Complete rear AP Racing Radi-CAL Competition Brake Kit. Fits all variants of the Porsche 991 GT3/3RS/2RS. Eliminates the need to remove the caliper for pad changes Retains OEM parking brake functionality Saves 18 unsprung lbs. vs. OEM iron brakes and weighs almost the same as the OEM PCCB system Jewel-like ENP caliper finish is incredibly durable and easy to clean AP Racing Radi-CAL with durable, ventilated stainless steel pistons (no ceramic piston caps to break) with anti-knockback springs Allows for the preservation of pricey OEM brake components Huge array of brake pad options from all major pad manufacturers Fits OEM 20" wheels without spacer 380x32mm, 72 vane AP Racing disc fits inside popular 19" wheels Every component designed to resist the heat of extended track sessions Pistons sized properly to allow for seamless integration with OEM master cylinder and ABS system Includes pad tension kit (eliminates noise) and disc burning at no additional cost Designed to work with Ap Racing front Brake Kit

AP Racing Radi-CAL 394mm Competition Brake Kit (Front) Fit The Following Cars Porsche 991 GT2RS  Porsche 991 GT3  Porsche 991 GT3RS  Porsche 718 GT4RS Complete front AP Racing Radi-CAL Competition Brake Kit for the Porsche 991 GT3/3RS/2RS and Porsche Cayman 718 GT4 RS. Features AP Racing Radi-CAL 9669 calipers for extreme durability! Clears many popular 19" and 20" track wheels Durable, ventilated stainless steel pistons (no ceramic piston caps to break) with anti-knockback springs Design eliminates the need to remove caliper for pad changes Saves 10 unsprung lbs. vs. OEM iron brakes and very close in weight to the OEM PCCB system Allows for the preservation of pricey OEM brake components Huge array of brake pad options from all major pad manufacturers 394x34mm, 84 vane AP Racing J Hook Discs Every component designed to resist the heat of extended track sessions Pistons sized properly to allow for seamless integration with OEM master cylinder and ABS system Includes the AP Racing pad tension kit and disc burning at no additional cost Designed to work with OEM rear brakes or the AP Racing Rear Brake Kit

AP Racing Radi-CAL Competition Brake Kit for Corvette C8 Z51(Rear) Complete Rear AP Racing Radi-CAL Competition Brake Kit for the Chevrolet Corvette C8 Z51 (2020+) Features AP Racing CP9669 Radi-CAL six piston calipers Jewel-like ENP caliper finish is incredibly durable and easy to clean Weighs roughly the same as the OEM Z51 rear brakes, despite more caliper pistons and 28mm larger discs 34mm, 72 vane AP Racing J Hook Discs Every component designed to resist the heat of extended track sessions Pistons sized properly to integrate with OEM master cylinder and ABS system Designed to work with AP Racing front Brake Kits

AP Racing Radi-CAL Competition 378mm Brake Kit for Corvette C8 Z06/Z07(Rear) AP Racing Radi-CAL Competition Front Brake Kit for C8 Corvette Z06 (all trims) Complete Rear AP Racing Radi-CAL Competition Brake Kit for the Chevrolet Corvette C8 Z06 / Z07 (2023+) Features AP Racing CP9669 Radi-CAL six piston calipers Jewel-like ENP caliper finish is incredibly durable and easy to clean Clears OEM Z07 5-spoke rear wheel without a spacer Saves approximately 10 unsprung lbs. from rear axle vs. OEM Z06 Iron brakes, despite more pistons in caliper 378x34mm, 72 vane AP Racing J Hook Discs Every component designed to resist the heat of extended track sessions Pistons sized properly to integrate with OEM master cylinder and ABS system Designed to work with OEM or AP Racing by Essex front Competition Brake Kits

AP Racing 345x30mm 2-piece J Hook Front Floating Racing Brake Rotors Fit The Following Cars  Corvette C8 Z51 Iron Rotor Rear AP Racing by Essex 2-piece Competition J Hook rear disc pair for Corvette C8 Z51 with iron discs 350mm x 28mm (13.78" x 1.10") 72 Vane, D66 Huge increase in airflow, cooling capacity, and durability vs. OEM discs Saves 2 lbs. unsprung weight per side vs. OEM iron discs Designed for: club racing, time trial, auto-x, HPDE Works with OEM calipers, no modifications required Ultralight, fully floating, anodized billet aluminum hat with float control/anti-rattle clips Sold/priced per pair. AP Racing J Hook Brake Rotors – The Gold Standard in Track Day & Racing Performance Engineered for professional motorsport, HPDE, and dedicated track day use, AP Racing’s J Hook Brake Rotors deliver uncompromising performance, thermal stability, and consistent braking power. These two-piece, floating rotors are built to handle the extreme demands of road racing, with design features derived from over 50 years of elite competition—including Formula 1, NASCAR, and IMSA. Unlike conventional one-piece rotors, AP Racing’s two-piece floating design features a billet aluminum hat mated to a cast iron disc via precision-engineered bobbins. This setup allows for controlled radial expansion under high heat, minimizing distortion and coning. The result? More even pad wear, a firmer pedal feel, and longer component life, even during extended lapping sessions or endurance racing. Floating hardware includes anti-knockback spring clips that reduce piston retraction while eliminating common NVH issues like rattling. Why Choose AP Racing J Hook Rotors? Advanced Cooling, Superior Bite, Unmatched Durability At the heart of every rotor is AP Racing’s proprietary high-carbon iron alloy, developed to withstand repeated thermal cycling without cracking or warping. Internally, directional vanes—far superior to OEM pillar or straight vane designs—maximize airflow and cooling. With 60 to 84 vanes per rotor, AP Racing achieves faster heat evacuation, reduced brake fade, and a more consistent friction surface. These rotors are left/right-specific for optimal airflow and balance. The exclusive J Hook slot pattern offers enhanced initial bite and promotes uniform heat distribution across the rotor face, reducing pad deposits and vibration. Unlike drilled rotors or straight-slot competitors, the J Hook design provides cleaner pad transfer during bed-in and superior modulation under braking—ideal for serious drivers who demand feedback and control. Yes, you might hear a little more whirr, but you’ll gain the stopping power, consistency, and longevity your lap times demand. Premium Components, Affordable Performance The rotor hats are CNC-machined from 6061-T6 billet aluminum and hard anodized for strength and heat resistance. Scalloped edges under the hat further assist heat dissipation. All hardware is U.S.-made to AP Racing spec, the same quality found on pro-level racing platforms. And while these rotors are race-proven, they’re also surprisingly cost-effective to replace. Don’t settle for cheap rotors that crack after a weekend—AP’s J Hook rings offer better durability and real long-term value. Fewer replacements mean more track time, less downtime, and peace of mind knowing you're running the best. Used by Champions. Trusted by Experts. From endurance racers to HPDE enthusiasts, AP Racing brake rotors are trusted worldwide for their reliability, longevity, and performance under pressure. Whether you're shaving seconds off your lap time or building a dedicated track car, the J Hook delivers a professional-grade solution that won’t let you down.   AP Racing J Hook Brake Rotors for Auto Racing, Track Days & HPDE Why Rotor Design Matters: Heat Expansion and Floating Technology As with most metals, iron brake discs expand significantly under heat. When temperatures rise, the disc grows radially—expanding in both diameter and circumference. Traditional one-piece rotors struggle to accommodate this natural expansion. As the outer edge pulls away from the center under heat stress, it creates a condition called “coning”—a distortion that compromises pad-to-rotor contact. This distortion can lead to uneven pad wear, brake tapering, and an inconsistent, long brake pedal. AP Racing two-piece floating brake rotors are purpose-built to eliminate these issues. Engineered with “float” built into the disc or hat assembly, these rotors feature oblong-shaped mounting holes that allow the hardware to slide as the disc heats up. This flexibility ensures the disc runs true within the caliper under high-temperature loads, effectively reducing distortion, minimizing pad taper and stress cracks, and promoting longer component life. Custom Mounting Hardware & Anti-Knockback Spring Clips AP Racing rotors utilize application-specific, U.S.-made mounting hardware—not generic bolts. These premium components are the exact parts used in AP’s professional motorsport products, engineered to withstand the rigors of competitive racing. To manage lateral disc motion that can push caliper pistons backward (known as knockback), AP Racing integrates anti-knockback spring clips on alternating bobbins—five on a ten-bolt setup, six on a twelve-bolt disc. These clips keep the aluminum hat and iron disc ring properly aligned while still allowing for radial float. Bonus: they eliminate annoying rattles and vibrations, ensuring a quieter, more refined braking experience. High-Performance Hat Design for Heat Isolation The disc hats in AP Racing’s two-piece floating rotors are CNC-machined from 6061-T6 billet aluminum and finished with a hard anodized coating. This high-strength aluminum alloy was selected for its ability to maintain structural integrity even at elevated temperatures. AP adds scalloped channels beneath the hat to further encourage airflow and heat evacuation from the outer disc face, minimizing thermal transfer to hubs and wheel bearings—helping reduce maintenance costs on these expensive components. Internal Vane Engineering: Airflow Optimization & Thermal Stability AP Racing’s internal vane design sets them apart from OEM and most aftermarket competitors. While many factory brake discs use non-directional pillar vanes (low-cost and NVH-focused), AP Racing rotors use directional vanes engineered for maximum airflow. These rotors are side-specific—meaning you’ll receive a unique left and right disc in each set—ensuring optimized cooling through strategic vane orientation and shape. Beyond that, AP Racing rotors feature a superior vane count, typically ranging from 60 to 84 vanes, compared to 30–48 in most aftermarket rotors. After extensive CFD and thermal analysis, this high vane count was proven to: Increase airspeed and thermal transfer Reduce recirculation and deflection at the disc face Minimize coning, cracking, and brake fade Deliver more even pad contact and extended rotor life J Hook Slot Pattern: Exclusive to AP Racing Slots and drill holes may improve initial bite, but they also introduce “cool spots” in the rotor face—areas of uneven heating that can lead to stress risers, cracks, and pad vibration. OEM rotors often avoid this by leaving the disc face blank, but that compromises bite and brake feel. AP Racing’s patented J Hook design, developed through rigorous R&D, solves this problem. The hooks are meticulously spaced around the disc’s circumference and from hat to edge, forming a continuous distortion path that ensures even heat distribution. This encourages uniform pad deposits during bed-in, helps reduce judder and cracking, and improves consistency under repeated high-load braking. In addition, the J Hook slots provide more leading edges for pads to grip than traditional curved slots or blank rotors. While this might generate a mild whirring sound during braking, the benefits—more bite, cleaner bedding, better pedal feel—make it the top choice for committed racers and serious track day drivers. Metallurgy Backed by 50+ Years of Motorsport Leadership AP Racing's reputation is built on performance, and their proprietary iron alloy used in J Hook rotors is no exception. Drawing from over five decades of elite motorsport experience, including 750+ Formula 1 wins and widespread use across NASCAR, AP’s engineers have developed a disc alloy that excels under sustained racing temperatures and stress. Where OEM discs focus on affordability and mass production, AP Racing’s J Hook rotors are purpose-built for motorsport durability and heat resistance. Affordable Replacement Cost: Serious Value for Serious Drivers Even the best brake rotors are consumables. When you drive hard—especially at the track—your discs will eventually wear out. That’s why AP Racing designed their replacement iron rings to be cost-effective, allowing you to replace worn parts without breaking the bank. Compare that to constantly buying cheap $150 rotors every weekend—rotors that can't handle the heat and need to be swapped frequently. With AP Racing’s J Hook rotors, you get longer service intervals, less downtime, and better performance over time, making them an incredibly smart long-term investment. Proven on Track. Trusted by Champions. Top-tier racing teams rely on AP Racing J Hook rotors for one reason: they perform under pressure. Whether you're running time trials, attending HPDE events, or competing in wheel-to-wheel racing, these rotors offer professional-grade reliability, safety, and performance. Bedding and preparation of AP Racing J Hook Disc Properly preparing your new brake discs before heavy use is extremely important. The goal of bedding-in your brake pads and discs is to mate them together properly and prepare them for heavy use.  When prepared properly, or bed-in, your pads will transfer a thin layer of material to the disc face (transfer layer).  The pads in your caliper will then actually ride on that thin layer of pad material you’ve put down on the rotor, rather than rubbing directly on the iron rotor face.  A good transfer layer is going to give you superior brake pedal feel, less noise, superior pad wear, and lower the chances of cracking your discs. Important Notes- PLEASE READ! First, make sure you are on a closed course to perform a proper bed-in.  Do NOT perform the procedure on public roads.  You need a stretch of asphalt with long straights, good visibility, and no potential obstructions.  Make sure you are in a position to safely and repeatedly attain the necessary speeds to perform the bed-in procedure.  A controlled racetrack is the best place to perform this procedure.  AP Racing and Competition Motorsport in no way suggest or condone speeding on public roads or breaking the law in your car, nor do we take responsibility for any damage or injury that occurs as a result of using our product or these procedures.  You are performing the bed-in procedure at your own risk.  During these procedures, it’s critical that you never come to a complete stop with your foot on the brake pedal.  If you have brake ducts on your car, you may want to block them off to allow your brake system to heat up easily. The procedure outlined below is a generic procedure for most types of mild race pad.  Please check your pad manufacturer’s recommended bed-in procedure. Accelerate to approximately 60mph and then decelerate down to 5 mph.  If your car has ABS, you should try to hold the brakes at a point just before ABS intervention.  Once the car slows to 5mph, immediately accelerate back up to about 60mph, and brake again to roughly 5mph.  Repeat this series of stopping and accelerating 8 to 10 times.  Again, do not come to a complete stop with your foot on the brake pedal. Cool the brake system down by cruising at 45mph+ for 5 to 10 minutes. Visually inspect your discs.  They should be a blue/grey color (instead of shiny silver), and have an even layer of pad material across and around the entire rotor face. If the AP Racing rotors don’t have a layer of pad material on them, perform another series of stops in the manner outlined above.

AP Racing 380x34mm 2-piece J Hook Front Floating Racing Brake Rotors Fit The Following Cars (w/ OEM Iron Rotors) Porsche 991 GT3 (Front) Porsche 991 GT3RS (Front) Porsche 981 GT4 (Front) AP Racing by Essex 2-piece Competition J Hook front disc pair for 981 GT4, 991.1 & 991.2 GT3 & GT3 RS with iron discs 380mm x 34mm (14.96" x 1.34") 72 Vane, D66 Huge increase in airflow, cooling capacity, and durability vs. OEM discs Saves 2 lbs. unsprung weight per side vs. OEM iron discs Designed for: club racing, time trial, auto-x, HPDE Works with OEM calipers, no modifications required Ultralight, fully floating, anodized billet aluminum hat with float control/anti-rattle clips Sold/priced per pair. AP Racing J Hook Brake Rotors – The Gold Standard in Track Day & Racing Performance Engineered for professional motorsport, HPDE, and dedicated track day use, AP Racing’s J Hook Brake Rotors deliver uncompromising performance, thermal stability, and consistent braking power. These two-piece, floating rotors are built to handle the extreme demands of road racing, with design features derived from over 50 years of elite competition—including Formula 1, NASCAR, and IMSA. Unlike conventional one-piece rotors, AP Racing’s two-piece floating design features a billet aluminum hat mated to a cast iron disc via precision-engineered bobbins. This setup allows for controlled radial expansion under high heat, minimizing distortion and coning. The result? More even pad wear, a firmer pedal feel, and longer component life, even during extended lapping sessions or endurance racing. Floating hardware includes anti-knockback spring clips that reduce piston retraction while eliminating common NVH issues like rattling. Why Choose AP Racing J Hook Rotors? Advanced Cooling, Superior Bite, Unmatched Durability At the heart of every rotor is AP Racing’s proprietary high-carbon iron alloy, developed to withstand repeated thermal cycling without cracking or warping. Internally, directional vanes—far superior to OEM pillar or straight vane designs—maximize airflow and cooling. With 60 to 84 vanes per rotor, AP Racing achieves faster heat evacuation, reduced brake fade, and a more consistent friction surface. These rotors are left/right-specific for optimal airflow and balance. The exclusive J Hook slot pattern offers enhanced initial bite and promotes uniform heat distribution across the rotor face, reducing pad deposits and vibration. Unlike drilled rotors or straight-slot competitors, the J Hook design provides cleaner pad transfer during bed-in and superior modulation under braking—ideal for serious drivers who demand feedback and control. Yes, you might hear a little more whirr, but you’ll gain the stopping power, consistency, and longevity your lap times demand. Premium Components, Affordable Performance The rotor hats are CNC-machined from 6061-T6 billet aluminum and hard anodized for strength and heat resistance. Scalloped edges under the hat further assist heat dissipation. All hardware is U.S.-made to AP Racing spec, the same quality found on pro-level racing platforms. And while these rotors are race-proven, they’re also surprisingly cost-effective to replace. Don’t settle for cheap rotors that crack after a weekend—AP’s J Hook rings offer better durability and real long-term value. Fewer replacements mean more track time, less downtime, and peace of mind knowing you're running the best. Used by Champions. Trusted by Experts. From endurance racers to HPDE enthusiasts, AP Racing brake rotors are trusted worldwide for their reliability, longevity, and performance under pressure. Whether you're shaving seconds off your lap time or building a dedicated track car, the J Hook delivers a professional-grade solution that won’t let you down.   AP Racing J Hook Brake Rotors for Auto Racing, Track Days & HPDE Why Rotor Design Matters: Heat Expansion and Floating Technology As with most metals, iron brake discs expand significantly under heat. When temperatures rise, the disc grows radially—expanding in both diameter and circumference. Traditional one-piece rotors struggle to accommodate this natural expansion. As the outer edge pulls away from the center under heat stress, it creates a condition called “coning”—a distortion that compromises pad-to-rotor contact. This distortion can lead to uneven pad wear, brake tapering, and an inconsistent, long brake pedal. AP Racing two-piece floating brake rotors are purpose-built to eliminate these issues. Engineered with “float” built into the disc or hat assembly, these rotors feature oblong-shaped mounting holes that allow the hardware to slide as the disc heats up. This flexibility ensures the disc runs true within the caliper under high-temperature loads, effectively reducing distortion, minimizing pad taper and stress cracks, and promoting longer component life. Custom Mounting Hardware & Anti-Knockback Spring Clips AP Racing rotors utilize application-specific, U.S.-made mounting hardware—not generic bolts. These premium components are the exact parts used in AP’s professional motorsport products, engineered to withstand the rigors of competitive racing. To manage lateral disc motion that can push caliper pistons backward (known as knockback), AP Racing integrates anti-knockback spring clips on alternating bobbins—five on a ten-bolt setup, six on a twelve-bolt disc. These clips keep the aluminum hat and iron disc ring properly aligned while still allowing for radial float. Bonus: they eliminate annoying rattles and vibrations, ensuring a quieter, more refined braking experience. High-Performance Hat Design for Heat Isolation The disc hats in AP Racing’s two-piece floating rotors are CNC-machined from 6061-T6 billet aluminum and finished with a hard anodized coating. This high-strength aluminum alloy was selected for its ability to maintain structural integrity even at elevated temperatures. AP adds scalloped channels beneath the hat to further encourage airflow and heat evacuation from the outer disc face, minimizing thermal transfer to hubs and wheel bearings—helping reduce maintenance costs on these expensive components. Internal Vane Engineering: Airflow Optimization & Thermal Stability AP Racing’s internal vane design sets them apart from OEM and most aftermarket competitors. While many factory brake discs use non-directional pillar vanes (low-cost and NVH-focused), AP Racing rotors use directional vanes engineered for maximum airflow. These rotors are side-specific—meaning you’ll receive a unique left and right disc in each set—ensuring optimized cooling through strategic vane orientation and shape. Beyond that, AP Racing rotors feature a superior vane count, typically ranging from 60 to 84 vanes, compared to 30–48 in most aftermarket rotors. After extensive CFD and thermal analysis, this high vane count was proven to: Increase airspeed and thermal transfer Reduce recirculation and deflection at the disc face Minimize coning, cracking, and brake fade Deliver more even pad contact and extended rotor life J Hook Slot Pattern: Exclusive to AP Racing Slots and drill holes may improve initial bite, but they also introduce “cool spots” in the rotor face—areas of uneven heating that can lead to stress risers, cracks, and pad vibration. OEM rotors often avoid this by leaving the disc face blank, but that compromises bite and brake feel. AP Racing’s patented J Hook design, developed through rigorous R&D, solves this problem. The hooks are meticulously spaced around the disc’s circumference and from hat to edge, forming a continuous distortion path that ensures even heat distribution. This encourages uniform pad deposits during bed-in, helps reduce judder and cracking, and improves consistency under repeated high-load braking. In addition, the J Hook slots provide more leading edges for pads to grip than traditional curved slots or blank rotors. While this might generate a mild whirring sound during braking, the benefits—more bite, cleaner bedding, better pedal feel—make it the top choice for committed racers and serious track day drivers. Metallurgy Backed by 50+ Years of Motorsport Leadership AP Racing's reputation is built on performance, and their proprietary iron alloy used in J Hook rotors is no exception. Drawing from over five decades of elite motorsport experience, including 750+ Formula 1 wins and widespread use across NASCAR, AP’s engineers have developed a disc alloy that excels under sustained racing temperatures and stress. Where OEM discs focus on affordability and mass production, AP Racing’s J Hook rotors are purpose-built for motorsport durability and heat resistance. Affordable Replacement Cost: Serious Value for Serious Drivers Even the best brake rotors are consumables. When you drive hard—especially at the track—your discs will eventually wear out. That’s why AP Racing designed their replacement iron rings to be cost-effective, allowing you to replace worn parts without breaking the bank. Compare that to constantly buying cheap $150 rotors every weekend—rotors that can't handle the heat and need to be swapped frequently. With AP Racing’s J Hook rotors, you get longer service intervals, less downtime, and better performance over time, making them an incredibly smart long-term investment. Proven on Track. Trusted by Champions. Top-tier racing teams rely on AP Racing J Hook rotors for one reason: they perform under pressure. Whether you're running time trials, attending HPDE events, or competing in wheel-to-wheel racing, these rotors offer professional-grade reliability, safety, and performance. Bedding and preparation of AP Racing J Hook Disc Properly preparing your new brake discs before heavy use is extremely important. The goal of bedding-in your brake pads and discs is to mate them together properly and prepare them for heavy use.  When prepared properly, or bed-in, your pads will transfer a thin layer of material to the disc face (transfer layer).  The pads in your caliper will then actually ride on that thin layer of pad material you’ve put down on the rotor, rather than rubbing directly on the iron rotor face.  A good transfer layer is going to give you superior brake pedal feel, less noise, superior pad wear, and lower the chances of cracking your discs. Important Notes- PLEASE READ! First, make sure you are on a closed course to perform a proper bed-in.  Do NOT perform the procedure on public roads.  You need a stretch of asphalt with long straights, good visibility, and no potential obstructions.  Make sure you are in a position to safely and repeatedly attain the necessary speeds to perform the bed-in procedure.  A controlled racetrack is the best place to perform this procedure.  AP Racing and Competition Motorsport in no way suggest or condone speeding on public roads or breaking the law in your car, nor do we take responsibility for any damage or injury that occurs as a result of using our product or these procedures.  You are performing the bed-in procedure at your own risk.  During these procedures, it’s critical that you never come to a complete stop with your foot on the brake pedal.  If you have brake ducts on your car, you may want to block them off to allow your brake system to heat up easily. The procedure outlined below is a generic procedure for most types of mild race pad.  Please check your pad manufacturer’s recommended bed-in procedure. Accelerate to approximately 60mph and then decelerate down to 5 mph.  If your car has ABS, you should try to hold the brakes at a point just before ABS intervention.  Once the car slows to 5mph, immediately accelerate back up to about 60mph, and brake again to roughly 5mph.  Repeat this series of stopping and accelerating 8 to 10 times.  Again, do not come to a complete stop with your foot on the brake pedal. Cool the brake system down by cruising at 45mph+ for 5 to 10 minutes. Visually inspect your discs.  They should be a blue/grey color (instead of shiny silver), and have an even layer of pad material across and around the entire rotor face. If the AP Racing rotors don’t have a layer of pad material on them, perform another series of stops in the manner outlined above.

AP Racing 345x30mm Replacement J Hook Front Floating Racing Brake Rotors Fit The Following Cars (w/ OEM Iron Rotors)- Center hat Excluded, rotor discs and hardware only. Replacement Disc Only For AP Racing 13.01.20042 Fit The Following Cars (w/ OEM Iron Rotors) Corvette C8 Z51  AP Racing by Essex 2-piece Competition J Hook front disc pair for Corvette C8 Z51 with iron discs 345mm x 30mm (13.59" x 1.18") 72 Vane, D66 Huge increase in airflow, cooling capacity, and durability vs. OEM discs Saves 2 lbs. unsprung weight per side vs. OEM iron discs Designed for: club racing, time trial, auto-x, HPDE Works with OEM calipers, no modifications required Ultralight, fully floating, anodized billet aluminum hat with float control/anti-rattle clips Sold/priced per pair of rotor rings (including hardware). AP Racing J Hook Brake Rotors – The Gold Standard in Track Day & Racing Performance Engineered for professional motorsport, HPDE, and dedicated track day use, AP Racing’s J Hook Brake Rotors deliver uncompromising performance, thermal stability, and consistent braking power. These two-piece, floating rotors are built to handle the extreme demands of road racing, with design features derived from over 50 years of elite competition—including Formula 1, NASCAR, and IMSA. Unlike conventional one-piece rotors, AP Racing’s two-piece floating design features a billet aluminum hat mated to a cast iron disc via precision-engineered bobbins. This setup allows for controlled radial expansion under high heat, minimizing distortion and coning. The result? More even pad wear, a firmer pedal feel, and longer component life, even during extended lapping sessions or endurance racing. Floating hardware includes anti-knockback spring clips that reduce piston retraction while eliminating common NVH issues like rattling. Why Choose AP Racing J Hook Rotors? Advanced Cooling, Superior Bite, Unmatched Durability At the heart of every rotor is AP Racing’s proprietary high-carbon iron alloy, developed to withstand repeated thermal cycling without cracking or warping. Internally, directional vanes—far superior to OEM pillar or straight vane designs—maximize airflow and cooling. With 60 to 84 vanes per rotor, AP Racing achieves faster heat evacuation, reduced brake fade, and a more consistent friction surface. These rotors are left/right-specific for optimal airflow and balance. The exclusive J Hook slot pattern offers enhanced initial bite and promotes uniform heat distribution across the rotor face, reducing pad deposits and vibration. Unlike drilled rotors or straight-slot competitors, the J Hook design provides cleaner pad transfer during bed-in and superior modulation under braking—ideal for serious drivers who demand feedback and control. Yes, you might hear a little more whirr, but you’ll gain the stopping power, consistency, and longevity your lap times demand. Premium Components, Affordable Performance The rotor hats are CNC-machined from 6061-T6 billet aluminum and hard anodized for strength and heat resistance. Scalloped edges under the hat further assist heat dissipation. All hardware is U.S.-made to AP Racing spec, the same quality found on pro-level racing platforms. And while these rotors are race-proven, they’re also surprisingly cost-effective to replace. Don’t settle for cheap rotors that crack after a weekend—AP’s J Hook rings offer better durability and real long-term value. Fewer replacements mean more track time, less downtime, and peace of mind knowing you're running the best. Used by Champions. Trusted by Experts. From endurance racers to HPDE enthusiasts, AP Racing brake rotors are trusted worldwide for their reliability, longevity, and performance under pressure. Whether you're shaving seconds off your lap time or building a dedicated track car, the J Hook delivers a professional-grade solution that won’t let you down.   AP Racing J Hook Brake Rotors for Auto Racing, Track Days & HPDE Why Rotor Design Matters: Heat Expansion and Floating Technology As with most metals, iron brake discs expand significantly under heat. When temperatures rise, the disc grows radially—expanding in both diameter and circumference. Traditional one-piece rotors struggle to accommodate this natural expansion. As the outer edge pulls away from the center under heat stress, it creates a condition called “coning”—a distortion that compromises pad-to-rotor contact. This distortion can lead to uneven pad wear, brake tapering, and an inconsistent, long brake pedal. AP Racing two-piece floating brake rotors are purpose-built to eliminate these issues. Engineered with “float” built into the disc or hat assembly, these rotors feature oblong-shaped mounting holes that allow the hardware to slide as the disc heats up. This flexibility ensures the disc runs true within the caliper under high-temperature loads, effectively reducing distortion, minimizing pad taper and stress cracks, and promoting longer component life. Custom Mounting Hardware & Anti-Knockback Spring Clips AP Racing rotors utilize application-specific, U.S.-made mounting hardware—not generic bolts. These premium components are the exact parts used in AP’s professional motorsport products, engineered to withstand the rigors of competitive racing. To manage lateral disc motion that can push caliper pistons backward (known as knockback), AP Racing integrates anti-knockback spring clips on alternating bobbins—five on a ten-bolt setup, six on a twelve-bolt disc. These clips keep the aluminum hat and iron disc ring properly aligned while still allowing for radial float. Bonus: they eliminate annoying rattles and vibrations, ensuring a quieter, more refined braking experience. High-Performance Hat Design for Heat Isolation The disc hats in AP Racing’s two-piece floating rotors are CNC-machined from 6061-T6 billet aluminum and finished with a hard anodized coating. This high-strength aluminum alloy was selected for its ability to maintain structural integrity even at elevated temperatures. AP adds scalloped channels beneath the hat to further encourage airflow and heat evacuation from the outer disc face, minimizing thermal transfer to hubs and wheel bearings—helping reduce maintenance costs on these expensive components. Internal Vane Engineering: Airflow Optimization & Thermal Stability AP Racing’s internal vane design sets them apart from OEM and most aftermarket competitors. While many factory brake discs use non-directional pillar vanes (low-cost and NVH-focused), AP Racing rotors use directional vanes engineered for maximum airflow. These rotors are side-specific—meaning you’ll receive a unique left and right disc in each set—ensuring optimized cooling through strategic vane orientation and shape. Beyond that, AP Racing rotors feature a superior vane count, typically ranging from 60 to 84 vanes, compared to 30–48 in most aftermarket rotors. After extensive CFD and thermal analysis, this high vane count was proven to: Increase airspeed and thermal transfer Reduce recirculation and deflection at the disc face Minimize coning, cracking, and brake fade Deliver more even pad contact and extended rotor life J Hook Slot Pattern: Exclusive to AP Racing Slots and drill holes may improve initial bite, but they also introduce “cool spots” in the rotor face—areas of uneven heating that can lead to stress risers, cracks, and pad vibration. OEM rotors often avoid this by leaving the disc face blank, but that compromises bite and brake feel. AP Racing’s patented J Hook design, developed through rigorous R&D, solves this problem. The hooks are meticulously spaced around the disc’s circumference and from hat to edge, forming a continuous distortion path that ensures even heat distribution. This encourages uniform pad deposits during bed-in, helps reduce judder and cracking, and improves consistency under repeated high-load braking. In addition, the J Hook slots provide more leading edges for pads to grip than traditional curved slots or blank rotors. While this might generate a mild whirring sound during braking, the benefits—more bite, cleaner bedding, better pedal feel—make it the top choice for committed racers and serious track day drivers. Metallurgy Backed by 50+ Years of Motorsport Leadership AP Racing's reputation is built on performance, and their proprietary iron alloy used in J Hook rotors is no exception. Drawing from over five decades of elite motorsport experience, including 750+ Formula 1 wins and widespread use across NASCAR, AP’s engineers have developed a disc alloy that excels under sustained racing temperatures and stress. Where OEM discs focus on affordability and mass production, AP Racing’s J Hook rotors are purpose-built for motorsport durability and heat resistance. Affordable Replacement Cost: Serious Value for Serious Drivers Even the best brake rotors are consumables. When you drive hard—especially at the track—your discs will eventually wear out. That’s why AP Racing designed their replacement iron rings to be cost-effective, allowing you to replace worn parts without breaking the bank. Compare that to constantly buying cheap $150 rotors every weekend—rotors that can't handle the heat and need to be swapped frequently. With AP Racing’s J Hook rotors, you get longer service intervals, less downtime, and better performance over time, making them an incredibly smart long-term investment. Proven on Track. Trusted by Champions. Top-tier racing teams rely on AP Racing J Hook rotors for one reason: they perform under pressure. Whether you're running time trials, attending HPDE events, or competing in wheel-to-wheel racing, these rotors offer professional-grade reliability, safety, and performance. Bedding and preparation of AP Racing J Hook Disc Properly preparing your new brake discs before heavy use is extremely important. The goal of bedding-in your brake pads and discs is to mate them together properly and prepare them for heavy use.  When prepared properly, or bed-in, your pads will transfer a thin layer of material to the disc face (transfer layer).  The pads in your caliper will then actually ride on that thin layer of pad material you’ve put down on the rotor, rather than rubbing directly on the iron rotor face.  A good transfer layer is going to give you superior brake pedal feel, less noise, superior pad wear, and lower the chances of cracking your discs. Important Notes- PLEASE READ! First, make sure you are on a closed course to perform a proper bed-in.  Do NOT perform the procedure on public roads.  You need a stretch of asphalt with long straights, good visibility, and no potential obstructions.  Make sure you are in a position to safely and repeatedly attain the necessary speeds to perform the bed-in procedure.  A controlled racetrack is the best place to perform this procedure.  AP Racing and Competition Motorsport in no way suggest or condone speeding on public roads or breaking the law in your car, nor do we take responsibility for any damage or injury that occurs as a result of using our product or these procedures.  You are performing the bed-in procedure at your own risk.  During these procedures, it’s critical that you never come to a complete stop with your foot on the brake pedal.  If you have brake ducts on your car, you may want to block them off to allow your brake system to heat up easily. The procedure outlined below is a generic procedure for most types of mild race pad.  Please check your pad manufacturer’s recommended bed-in procedure. Accelerate to approximately 60mph and then decelerate down to 5 mph.  If your car has ABS, you should try to hold the brakes at a point just before ABS intervention.  Once the car slows to 5mph, immediately accelerate back up to about 60mph, and brake again to roughly 5mph.  Repeat this series of stopping and accelerating 8 to 10 times.  Again, do not come to a complete stop with your foot on the brake pedal. Cool the brake system down by cruising at 45mph+ for 5 to 10 minutes. Visually inspect your discs.  They should be a blue/grey color (instead of shiny silver), and have an even layer of pad material across and around the entire rotor face. If the AP Racing rotors don’t have a layer of pad material on them, perform another series of stops in the manner outlined above.