AP Racing ⨉ Essex CP9451 Radi-CAL ENP Competition Rear Brake Kit for RZ34 Nissan Z & Z34 Nissan 370Z

AP Racing ⨉ Essex CP9451 Radi-CAL ENP Competition Rear Brake Kit for RZ34 Nissan Z & Z34 Nissan 370Z

Elevate your RZ34 Nissan Z’s rear braking system with the AP Racing ⨉ Essex CP9451 Radi-CAL ENP Competition Rear Brake Kit. Although it matches the weight of the OEM Sport Package setup, this kit boasts larger AP discs (15mm more in diameter and 10mm thicker), presenting a significant upgrade. It also maintains the functionality of your OEM parking brake. The kit features the state-of-the-art AP Racing CP9451 Radi-CAL four-piston calipers, distinguished by their jewel-like ENP finish that ensures remarkable durability and easy maintenance. Its 365x30mm, 72 vane AP Racing 2-piece floating discs are each designed to resist the intense heat of prolonged track sessions. Pistons are sized for perfect integration with the OEM master cylinder and ABS system, ensuring flawless operation. Ideally designed to pair with their front AP Racing by Essex CP9668 and CP9660 Competition Brake Kits, this rear brake kit promises an unrivaled transformation of your braking performance.

Radi-CAL

• AP Racing has revolutionized the field of brake technology with its patented Radi-CAL asymmetrical brake caliper design. This groundbreaking design incorporates cutting-edge technologies such as Computer Aided Design (CAD) and Finite Element Analysis (FEA), pushing the boundaries of traditional caliper norms. The Radi-CAL calipers are renowned as the pinnacle of brake caliper technology, boasting a unique and organic shape that represents a new era of innovation. Since their introduction in 2007, these calipers have consistently exceeded expectations, delivering exceptional performance on professional motorsport race tracks. Their impressive track record of victories solidifies their status as a game-changing force in brake performance.
• Benefits of the Radi-CAL Design
  • Significant Stiffness Enhancement – The Radi-CAL calipers exhibit a remarkable advancement of over 30% in both static and dynamic stiffness compared to traditional calipers. This substantial increase in stiffness effectively reduces deflection under load, resulting in enhanced pedal feel, precise modulation, uniform pad wear, and prolonged caliper lifespan.
  • Substantial Weight Reduction – Despite the notable increase in stiffness, the Radi-CAL design achieves a substantial reduction in caliper weight by eliminating unnecessary mass. This weight reduction contributes to improved overall vehicle performance.
  • Optimized Airflow – Meticulously engineered, the Radi-CAL calipers are designed to optimize airflow, facilitating efficient air circulation around and through the caliper. This optimized airflow enhances heat dissipation and cooling, elevating the overall performance of the braking system.
  • Efficient Packaging – The asymmetric caliper profile and internal fluid porting of the Radi-CAL design ensure efficient packaging. This thoughtful design enables flexible installation options without compromising performance, allowing for optimal integration into various vehicle configurations.

CP9451 PRO5000R Calipers – The Everyman Radi-CAL

• After eight years of continuous development, multiple iterations, and advancements in manufacturing techniques, the Radi-CAL concept has finally transformed into an accessible solution for racers and enthusiasts across all levels and budgets. While many products claim racing origins, the Pro5000R calipers undeniably possess a genuine pedigree. They are direct descendants of the cutting-edge calipers utilized in current F1 and Sprint Cup racing. Unconventional in appearance, these calipers embody the essence of pure racing design: sleek, minimalist, and exceptionally efficient. While they remain true to the Radi-CAL design philosophy of the past, they also incorporate remarkable new features that enhance their practicality, convenience, and allure. In essence, they represent the lightest, stiffest, and most technologically advanced brake calipers ever within the reach of the average enthusiast.
• Traditionally, these intricate calipers were machined from specialized aluminum alloy billets. The process of machining away excess material to achieve the final form proved time-consuming and expensive. Consequently, the price of these calipers remained prohibitively high for the average club racer, time-trialer, or HPDE participant. Thankfully, the Pro5000R calipers utilize an innovative drop-forging technique that has significantly reduced manufacturing costs, making these extraordinary calipers more accessible to a broader range of enthusiasts.

Radi-CAL = Massive Dynamic Stiffness Increase

• Throughout the years, various approaches have been employed to reduce the size of brake calipers while maintaining their necessary stiffness. These strategies have encompassed robust caliper bridge designs, two-piece calipers with steel through-bolts, the utilization of advanced materials like Beryllium and MMC, the transition from casting to forging, and the adoption of monobloc designs. These innovations aimed to make calipers lighter, more compact, and stiffer. However, the conventional rectangular, boxy shape has remained the prevailing standard for calipers.
• Challenging the efficiency of this rectangular box design, AP Racing has questioned its effectiveness for brake calipers. They have demonstrated that the traditional design falls short in optimization. When a caliper clamps brake pads against a spinning disc, a substantial tangential friction force arises between the pads and the disc. This force pulls the caliper towards the rotating disc with considerable strength. The caliper resists this force through its rigid mounting points on the spindle.
• During braking events, the dynamic load exerted on the caliper causes it to undergo twisting or deformation, adopting a parallelogram shape. Recognizing the significance of this dynamic force, AP Racing intentionally designed the Radi-CAL caliper to address it. Unlike traditional calipers that were developed without direct consideration of the forces they would encounter, the Radi-CAL caliper was specifically engineered around the forces generated during braking.
• The Radi-CAL caliper optimally distributes its body mass along a diagonal axis, rather than concentrating it solely at the ends of the caliper. This design allows the caliper mass to better withstand the forces acting on it during braking, rather than relying solely on an empty box structure. By redistributing the mass, the caliper achieves significant overall weight reduction by eliminating non-essential, non-load-bearing material from its body.
• WHAT DOES THE ABOVE MEAN FOR YOU, THE DRIVER? IT MEANS A SIGNIFICANTLY FIRMER BRAKE PEDAL WITH SUPERIOR MODULATION UNDER ALL CONDITIONS. IT ALSO MEANS MORE EVEN PAD WEAR WITH LESS TAPERING, AND A LONGER CALIPER SERVICE LIFE.

Radi-CAL = Ultra-Lightweight, Compact Design with High Airflow

• As previously mentioned, the Radi-CAL design philosophy not only considers what is present but also what is absent. Deliberately redistributing the mass of the caliper, voids are created in unconventional areas. This strategic removal of mass from the caliper body optimizes its size, resulting in an impressively lightweight and compact design. While competing six-piston calipers typically weigh between 9 to 12 lbs, the CP9668 weighs a remarkably low 6.8 lbs.
• Essex’s approach to brake kit design has always prioritized efficiency, recognizing that excessive size adds unnecessary weight. The Radi-CAL design perfectly aligns with this philosophy. Many brake packages on the market face challenges with wheel fitment, featuring oversized discs and 12-piston calipers that can make it difficult to fit behind OEM wheels or lightweight alternatives. The goal is to save unsprung weight and enable the use of smaller, lighter wheels, which are more accessible and cost-effective when paired with R compound tires. Thoughtfully designed components that prioritize performance eliminate the need for excessively heavy calipers. Concerns about stiffness resulting from mass reduction are unfounded, as AP Racing’s Pro5000R calipers are not only lightweight but also exceptionally stiff, specifically engineered for racing applications.
• A notable feature of the Pro5000R range is the positioning of the bleed screws and fluid pathways. These calipers incorporate internal fluid porting, with only two bleed screws located on the inner caliper half. This configuration minimizes the risk of damaging a bleed screw or crossover pipe during wheel changes. Additionally, it reduces the number of bleed screws that require attention during brake fluid replacement. The absence of external piping and bleed screws also allows for rounded outer corners, improving clearance with wheel spokes.
• Compared to traditional calipers, the design of the Pro5000R enables increased airflow between and around the pistons and brake fluid pathways. This enhanced airflow contributes to better overall system operating temperatures, resulting in improved performance and durability.

Two-Piece, Drop-Forged Caliper Body

• Calipers have traditionally been produced by machining a solid block of exclusive aluminum alloy, utilizing a design called monobloc. In this design, the piston bores and piston seal grooves are machined using a right-angle machine tool that needs to be inserted into the caliper. Machining away all the material using specialized tools and multiple setups to achieve the final shape is a labor-intensive and expensive process. As a result, monobloc Radi-CAL calipers have been priced beyond the budget of the average club racer, time-trialer, or HPDE participant. However, the introduction of a new two-piece drop-forging process has made the Pro5000R caliper a reality. This innovative manufacturing technique allows conventional machine tools direct access to the piston bores, significantly reducing production time and cost while still maintaining an exceptionally rigid structure. With this new process, the Pro5000R caliper offers the same high-performance benefits as the monobloc design but at a more affordable price point.

ENP (Electroless Nickel Plated) Finish

• One notable drawback of typical aftermarket calipers is their finish. Most aftermarket calipers are coated with paint, available in various colors such as red, black, or gold. The purpose of this painted finish is twofold: to provide an attractive appearance and to protect against corrosion in harsh winter conditions. However, when these painted calipers are used in track environments, they often encounter several issues that can diminish their appearance and durability over a relatively short period of time.
• The primary factor contributing to these issues is heat. Paint and powder coat finishes are not designed to withstand the high temperatures experienced on the track. Powder coat finishes, in particular, are susceptible to shrinkage problems. When the caliper heats up, the powder coat layer expands, but it may not shrink back in sync with the caliper body when it cools down. This can lead to cracking and deterioration of the loose shell of the finish.
• Paint finishes can also face similar challenges depending on their application. Even among calipers from the same manufacturer, slight variations in the painted finish can be observed. Some calipers may have thicker coats of paint, while others have thinner ones, resulting in slight differences in color shades. Achieving a consistent paint application requires a controlled environment, and without it, variations are likely to occur. Thick coats of paint can appear soft and are prone to cracking, similar to the issues with powder coat finishes mentioned earlier. Conversely, insufficient paint coverage leads to an uneven look and inadequate protection for the underlying aluminum. Furthermore, both paint and powder coat finishes can experience noticeable color shifting when exposed to heat. Red may turn into maroon, black can become less visually appealing, and gold may transform into a less desirable shade of brown.
• These issues highlight the unsuitability of traditional paint and powder coat finishes for high-performance track environments. To address this, alternative finishing options are available that offer superior resistance to heat and provide long-lasting protection and visual appeal.

Ventilated, Domed Back, Stainless Steel Pistons

• There is an ongoing debate concerning the use of aluminum pistons in track calipers, with some individuals arguing that the pistons and caliper body should expand at the same rate when heated. However, this argument lacks substantiated evidence and validity. In reality, reputable race caliper manufacturers worldwide exclusively utilize stainless steel or titanium pistons in their high-performance calipers, based on their superior performance.
• Stainless steel pistons offer significant advantages, particularly in creating a thermal barrier that effectively minimizes heat transfer to the brake fluid. This barrier helps prevent a soft pedal caused by fluid fade during intense track use. The superiority of stainless steel pistons has been consistently demonstrated across various levels of motorsport. Despite the higher cost associated with them, the Pro5000R calipers from AP Racing are equipped with meticulously machined stainless steel pistons, distinguishing them from many aftermarket calipers that use pressed aluminum pistons.
• To further enhance piston stiffness, AP Racing has incorporated a domed shape at the back of the piston. While it may appear to be a minor design element, the introduction of domed back pistons in professional racing has received overwhelmingly positive feedback from drivers. The domed back significantly increases stiffness, resulting in an improved pedal feel that can be palpably felt. This design has become the benchmark against which all other designs are measured.
• In addition to the domed back, the pistons in the Pro5000R calipers are equipped with ventilation for enhanced heat resistance. The presence of air gaps around the edges of the pistons facilitates additional air circulation, contributing to the cooling process around the pistons. These features collectively slow down and repel the influx of heat into the brake fluid, effectively preventing brake fluid boiling and fade under demanding conditions.

Anti-Knockback Springs

• AP Racing calipers feature stainless steel pistons that incorporate anti-knockback (AKB) springs, which may come as a surprise to some. However, these springs serve a crucial purpose in addressing the issue of knockback, which can be unsettling when experienced during braking after a series of S-turns.
• Knockback is commonly observed in fixed calipers and occurs when the wheel, hub, and bearings of a car deflect during cornering, causing the brake disc to move out of synchronization with the caliper and brake pads. This deflection pushes the brake pads apart and retracts the caliper pistons into their bores. However, the piston seals do not have enough tension to fully return the pistons to their original position, resulting in slack within the system. When the brake pedal is applied, it continues to drop until the slack is taken up.
• The inclusion of anti-knockback springs in AP Racing calipers helps alleviate this issue by exerting tension on the backside of the pistons. When the disc deflects and makes contact with the pistons, the springs push the pistons back into their proper position, reducing the slack in the system. This results in less pedal drop and a more confident braking experience, especially when approaching heavy brake zones.
• It is important to note that the inclusion of lightweight AKB springs does not have significant downsides as long as the caliper is designed to accommodate them. When properly designed and implemented, AKB springs do not cause increased drag or wear on the pads and discs. The shape and material of the piston seals are carefully considered to ensure optimal performance.
• In AP Racing competition calipers, the seals are not just rings through which the piston slides; they are designed with angles and provide initial friction to limit movement. As the suspension compresses and the disc moves laterally, the seals deform slightly, creating a tension or friction that must be overcome before the piston starts moving through the seal ring. The AKB springs add additional resistance and assist in returning the piston to its neutral position.
• When properly designed seals and springs are employed, the goal is to keep the piston in the neutral position, not pressed against the disc. The piston can still slide freely in either direction, but initially, a bit of friction or tension must be overcome to initiate movement. This arrangement ensures that AP Racing calipers do not cause unnecessary drag or wear on the braking system components.
• Overall, the inclusion of AKB springs in AP Racing calipers addresses the issue of knockback, providing a more reliable and consistent braking experience without compromising performance or causing additional wear on the pads and discs.

High Temperature, Low Drag Seals Without Dust Boots

• Essex often encounters an unexpected question from potential customers regarding the maintenance and rebuilding of calipers in their kits, specifically due to the absence of dust boots on the pistons. This question often perplexes them because it lacks intuitive reasoning. In reality, a product that is specifically designed to withstand the extreme high-heat conditions of track use should require less maintenance compared to brake components intended for low-speed and low-temperature street driving.
• To clarify, there is often confusion between piston seals and dust boots. All calipers feature seals, which are small rubber rings inside the piston bores that prevent brake fluid from leaking around the pistons. OEM caliper seals are not engineered to endure constant exposure to high temperatures without becoming brittle and prone to leaking. However, Essex’s calipers utilize high-temperature seals identical to those used in NASCAR Sprint Cup, ALMS, DTM, and other professional racing series. These high-temperature seals are less likely to become brittle and wear out under the demanding conditions of high-heat track use, resulting in significantly reduced replacement and servicing requirements.
• It is important to note that most aftermarket calipers are designed for year-round road use and come equipped with external dust boots. These rubber boots stretch as the pistons extend, aiming to keep contaminants out of the piston bore. While this concept may initially seem appealing, Essex has observed instances where customers have burned through these boots in a single 20-minute track session. Once the boots are burned, the pistons are left with tattered and burnt rubber fragments that provide no benefits. Considering that the boots are quickly destroyed during track use, it becomes unnecessary to include them in the caliper design, eliminating the mess they create.
• Essex’s focus is on providing durable and reliable calipers that can withstand the demanding conditions of track use without sacrificing performance. By utilizing high-temperature seals and omitting dust boots, their calipers require less maintenance, offer enhanced longevity, and deliver consistent performance on the track.

Simple Pad Change with One Bolts

• When the time comes to replace your brake pads, it’s understandable that you may not look forward to the task. However, with the Pro5000R calipers, this process becomes effortless. Say goodbye to struggling with hammers, punches, or pliers. The bridge bolts on AP’s calipers can be effortlessly removed using a 6mm hex wrench. Changing pads will now be faster than ever before. In fact, you’ll spend more time taking off the wheel than actually swapping out the pads. This translates to less time spent tinkering in the paddock and more time enjoying the exhilaration of driving.

Lifetime Professional Reconditioning Service

• Essex holds the prestigious distinction of being the official AP Racing caliper reconditioning center in North America. Their team comprises highly skilled service technicians who possess specialized expertise in the meticulous rebuilding of a multitude of AP Racing calipers annually. These esteemed calipers are entrusted to Essex by renowned motorsport teams, including those participating in prestigious events such as NASCAR Sprint Cup and ALMS. This recognition serves as a testament to Essex’s unparalleled proficiency and esteemed reputation within the industry.
• Removal and Shipping – To initiate the service process, simply detach your calipers from the vehicle, drain and clean them thoroughly, and send them back to Essex.
• Hardness Testing – Once disassembled, your calipers undergo Rockwell hardness testing, a meticulous assessment to evaluate their fatigue and stiffness levels. This comprehensive test enables us to determine the extent of wear and make informed decisions regarding whether the calipers should be rebuilt or replaced. Identifying fatigued calipers is essential to prevent issues such as pad tapering, increased pad wear, seal leakage, and diminished pedal firmness.
• Ultrasonic Cleaning – Calipers that pass the hardness test proceed to undergo a thorough cleaning process utilizing our advanced ultrasonic cleaner. This cutting-edge cleaning method surpasses traditional hand-cleaning techniques, effectively removing all dirt, debris, and brake fluid for a pristine result.
• Inspection and Re-Assembly – Every serviceable component of the caliper, including seals, abutment plates, pistons, and bleed screws, undergoes a meticulous inspection. Any components showing signs of wear or damage are replaced to ensure optimal performance and reliability.
• Cyclical Pressure Testing – Once rebuilt, the calipers undergo rigorous cyclical pressure testing on our specialized bench. This meticulous testing procedure verifies proper functionality and identifies any potential leaks that may occur under specific pressure conditions. By subjecting the calipers to these rigorous tests, we ensure that they meet our stringent quality standards before being returned to you.

Discs – AP Racing Competition J Hook

• The AP Racing J Hook discs included in this system represent the pinnacle of endurance racing performance. These high-quality components are meticulously engineered to withstand the most demanding conditions you can throw at them. With a reputation for exceptional durability, these discs have a proven track record in professional racing, having achieved numerous victories and championship titles in prestigious events like ALMS, Rolex, and Grand Am. Their outstanding performance and established reliability make the AP Racing J Hook discs the perfect choice for drivers who seek uncompromising performance and long-lasting endurance in their racing endeavors.

Two-Piece Floating Design with Aluminum Hat

• When subjected to heat, iron brake discs, like most metals, undergo significant expansion, resulting in an increase in diameter and circumference. This expansion presents a challenge for one-piece disc designs, as they lack provisions to accommodate this expansion. As depicted in the image below, the disc’s outer edges pull away from the center when heated, causing distortion and lift, a phenomenon known as coning. When the disc is mounted vertically in the caliper, coning directly affects the contact between the brake pads and the disc, leading to uneven wear, tapering, and an extended brake pedal.
• In contrast, two-piece discs are specifically engineered to address the expansion caused by heat. This is achieved by incorporating “float” either in the disc itself or in the disc hat/bell. In the example provided, the float is integrated into the disc. If you closely examine the picture, you will notice that the mounting holes for the hat attachment bobbins are oblong rather than circular. These channels allow the hat mounting hardware to slide as the disc heats up and expands. This design enables the disc to maintain its proper position within the caliper without distortion. By minimizing distortion, stress cracks, and pad taper, this design approach ensures optimal performance and long-lasting durability of the braking system.

Mounting Hardware and Anti-Knockback Spring Clips

• When carefully examining the mounting hardware used in Essex’s Competition Kits, you will discover several often overlooked details that set them apart from inferior products. These components are not generic bolts sourced from a local retail store but are custom-made exclusively for Essex and AP Racing in the USA. They are the same high-quality components used in professional racing applications.
• As mentioned earlier regarding the piston springs and knockback, managing the lateral movement of the disc is crucial during track driving. To address this, we incorporate anti-knockback spring clips at every other disc attachment point. For example, a ten-bolt disc assembly would include five spring clips, while a twelve-bolt disc would have six. These spring clips play a vital role in maintaining alignment between the disc hat and the iron ring, while also allowing for radial expansion and floatation of the disc. In addition, they provide the added benefit of preventing any rattling or noise originating from the disc hat and iron disc assembly.

Hat Design

• In addition to their other notable advantages, floating two-piece discs offer an extra benefit of reducing heat conduction to the hubs and bearings. This reduction in heat transfer plays a significant role in minimizing wear and tear on these crucial components, resulting in an extended lifespan. The disc hats, an integral part of the assembly, are meticulously crafted from 6061 heat-treated billet aluminum, ensuring exceptional strength even in high-temperature conditions. To further optimize their performance, the hats undergo a hard anodized coating treatment. The choice of material and coating is specifically tailored to withstand the intense heat generated by the iron discs. Notably, the hats feature scallops on the underside, facilitating efficient heat dissipation along the outer face of the disc once they are installed.

Internal Vane Quantity and Quality

• The design of AP Racing J Hook discs sets them apart from OEM-style discs and other aftermarket brands, particularly in terms of their internal vane design. Unlike pillar vane designs commonly found in OEM discs, AP Racing discs utilize a different approach. Pillar vanes consist of interconnected posts or pillars that connect the two halves of the disc, which can cause turbulence as air passes through. This design prioritizes disc face stability and cost efficiency rather than efficient heat evacuation. Another type of vane design seen in certain OEM discs is the straight, non-directional internal vane, which offers better airflow than pillar vanes but still falls short of the directional vanes featured in AP Racing discs.
• AP Racing discs employ directional vanes that are optimized to spin in a specific direction, maximizing the airflow passing through the disc. Each pair of AP Racing discs is handed, meaning there is a unique left and right disc that cannot be interchanged. The vane orientation and shape are meticulously engineered to promote smooth airflow and enhance cooling performance.
• Moreover, AP Racing discs outperform many aftermarket discs in terms of vane count. While most aftermarket discs have 30 to 48 vanes, AP Racing’s J Hook discs boast a higher vane count, typically ranging from 60 to 84 depending on the application. The increased vane count enables higher airspeed, improved heat transfer, reduced air recirculation between vanes, and decreased deflection at the disc face. Compared to OEM-style or competitor’s 48 vane discs, AP Racing’s 60+ vane discs demonstrate enhanced resistance to coning, distortion, and cracking. They also provide benefits such as reduced brake fade, minimized judder, more consistent pad contact, and extended service life.
• An examination of the internal vane design clearly reveals the unique features of AP Racing J Hook discs. Notably, these discs have a wider air gap between the disc faces, allowing for significantly increased airflow into and through the disc. The uniform and directional vane design further enhances the airflow performance.
• It is important to emphasize that the majority of cooling air entering a brake disc originates from the back side of the discs, particularly when brake ducts are utilized. A comparison between an OEM pillar vane disc, an OEM dual-cast disc (technically a two-piece disc), and the AP Racing J Hook disc highlights the differences. The AP Racing disc offers a clear and unobstructed path for cooling air to enter and flow through the disc, while the OEM discs feature narrower inlet ports and potential obstructions that hinder the flow. As a result, the AP Racing disc maintains significantly lower temperatures, reducing the likelihood of cracking and wear.

Exclusive AP Racing J Hook Slot Pattern

• When modifications like slots or holes are introduced to a brake disc, they can affect heat transfer in various ways. These modifications can create cool spots around the slots or holes when the disc heats up, which is not ideal. Ideally, heat should be evenly distributed across the disc to allow for effective cooling through airflow and radiation. The presence of cool spots can lead to areas of stress concentration and increase the likelihood of disc cracking. Moreover, cool spots can cause uneven distortion of the disc’s face, resulting in uneven pad deposits, vibrations, and judder.
• Original Equipment Manufacturer (OEM) discs address this issue by leaving the disc face blank, thereby avoiding the formation of cool spots. While this approach reduces the risk of noise, vibration, and harshness (NVH), it also leads to a decrease in pad bite and the tactile feedback felt through the brake pedal. On the other hand, many aftermarket discs on the market feature straight slots, which tend to create cool spots across the disc face between the slots.
• Extensive research and development conducted by AP Racing has resulted in the development of the J Hook design, which offers a solution to these challenges. The J Hook design creates a consistent pathway of evenly distorted material on the disc face. The hooks are strategically spaced around the disc’s circumference and from the inside edge (where the hat attaches) to the outer edge, with a slight overlap. This design promotes even heat distribution and distortion across the disc, reducing the risk of cracking. Additionally, the uniform heating of the disc facilitates the formation of a uniform transfer layer of pad material during the bedding-in process.

Complex Metallurgy Developed Through 50+ Years of Experience

• With a legacy of over fifty years in brake component design, AP Racing has an outstanding track record that speaks for itself. Their components have contributed to the success of cars that have emerged victorious in over 750 Formula 1 races, a testament to their expertise and reliability. In fact, when you observe the NASCAR Sprint Cup grid on any given race weekend, you will find AP J Hook discs adorning 75% or more of the cars.
• Building upon this wealth of experience, AP Racing has developed their own proprietary iron alloy, renowned for its exceptional durability. Every detail of this alloy is carefully crafted to withstand the harsh conditions it will encounter. Unlike OEM discs that prioritize cost-effectiveness and ease of production, AP Racing’s disc design objectives are set apart. They maintain an unwavering focus on delivering superior performance and unwavering reliability, ensuring that their products can endure the most demanding usage without compromise.

Caliper Brackets & Hardware

• The caliper brackets included in this kit are crafted with meticulous precision from heat-treated 6061 T6 billet aluminum, renowned for its exceptional strength and durability. To further enhance their resilience, these brackets undergo a rigorous hard anodizing process. We maintain the same high standards employed in professional racing, utilizing aircraft-grade hardware that meets stringent quality requirements.
• One notable advantage of our brackets lies in their thoughtfully designed cutaway feature. This unique design allows for seamless compatibility with various brake duct kits available in the market. The cutaway design ensures a precise and secure fit, enabling efficient cooling and optimal airflow to the brakes—a crucial element for achieving peak performance on the track.

Brake Ducting

• Essex discourages the use of aftermarket brake ducts in conjunction with their Competition Brake Kits based on their extensive experience. They have encountered challenges in achieving effective airflow from the front of the car to the center of the brake discs due to limitations in packaging. The narrow diameter of the duct hoses and restricted space within the fender well make it difficult to install properly-sized hoses that can provide sufficient cooling. Furthermore, many aftermarket systems direct cooling air to incorrect locations, resulting in uneven cooling and temperature variations across the disc surface. These temperature differentials can contribute to premature cracking.
• In addition, the plates used to attach brake ducts at the wheel hub can inadvertently trap heat against the inner disc face, leading to increased system temperatures. Given these considerations, Essex does not recommend the use of aftermarket brake ducts.
• If your vehicle is equipped with OEM brake ducts that channel air into the wheel well or has air deflectors within the wheel area, it is acceptable to retain them. However, if you have installed an Essex Designed AP Racing Competition Brake Kit and notice higher-than-expected temperatures during operation, it is advisable to contact Essex to discuss possible solutions.
• It is crucial not to attach any additional components between the caliper bracket and the suspension upright. Attaching ears or tabs from a brake duct system between the bracket and upright can misalign the caliper from its intended orientation, posing a serious risk of damage to the entire brake system or the vehicle. The bracket should be directly bolted to the upright as originally intended, without any objects placed in between.

Spiegler Stainless Steel Brake Lines

• The Competition Kits come equipped with high-quality stainless steel brake lines that are recognized for their exceptional craftsmanship. Spiegler lines stand out from other alternatives available in the market, offering a comprehensive range of features that provide unmatched performance advantages.

Disc Burnishing / Bedding Service

• Properly preparing your brake discs before hitting the track is crucial to avoid potential issues such as juddering, vibration, and cracking. However, conducting these preparations at the circuit can be challenging and time-consuming, and it may also pose risks to other drivers. Additionally, on-track preparations can be inconsistent due to factors like changing weather conditions and traffic, making it difficult to achieve the desired level of repeatability for optimal bedding and consistent performance.
• To address these concerns, Essex now offers a professional burnishing service to all customers, extending this service beyond their racing clientele. This service allows individuals to have select Competition Brake Kits pre-burnished at Essex’s facility. With their extensive experience in servicing discs for elite teams, Essex’s skilled technicians employ an automated computer system and follow a rigorous regime based on feedback from top drivers and crews. This ensures maximum efficiency from AP Racing disc brake sets.
• It’s important to note that the pads included in your kit will not be pre-burnished. In other words, the burnishing procedure for the discs does not have to be performed with the exact set of pads that come with your kit. Essex will perform the burnishing process on the discs using the pad compound of your choice, ensuring that you can enjoy the benefits of the procedure while using the provided pads from your kit.

Features

• Weighs roughly the same as the OEM Sport Package setup, despite AP discs being significantly larger (15mm larger in diameter and 10mm thicker).
• Retains OEM parking brake functionality.
• Features AP Racing CP9451 Radi-CAL four piston calipers.
• Jewel-like ENP caliper finish is incredibly durable and easy to clean.
• 365x30mm, 72 vane AP Racing 2-piece floating 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.
• Designed to work with our front AP Racing by Essex CP9668 and CP9660 Competition Brake Kits

What’s In The Box

• One pair AP Racing CP9451 Radi-CAL Pro5000R racing calipers in ENP Finish (Electroless Nickel Plated).
• One pair 365x30mm AP Racing 72 vane, J Hook racing discs, with fully floating 6061 hard anodized aluminum hats and attachment hardware.
• One pair caliper mounting brackets and hardware.
• One pair Spiegler Stainless Steel Brake Lines with abrasion resistant coating.
• Detailed installation instructions.
• Brake pads are NOT included with this system.
  • Selecting the ideal racing brake pads is a matter of personal choice. Unlike other manufacturers who provide brake kits with low-quality pads, Essex offers a different approach. They have eliminated the cost of pads from their system, allowing customers to have full control over their pad selection. When you purchase the kit, you have the freedom to choose a set of front pads that align with your specific preferences and requirements. Essex provides this opportunity at a substantial discount compared to the retail price, ensuring that you can customize your brake setup without incurring any unnecessary expenses. This puts you in the driver’s seat, enabling you to tailor your braking system precisely to your liking.
  • DS1.11 – Renowned for its performance in endurance racing, the DS1.11 brake pad is a popular choice. It falls within the moderate range of endurance racing compounds, offering a lower friction coefficient (mu) compared to the 3-12 pad. As temperatures increase, the DS1.11 delivers decreasing torque, allowing for improved control when using street tires. While it may have a shorter lifespan due to its less aggressive interaction with discs, it still exhibits impressive resistance to high temperatures. Its reputation is built on the sensation it provides, delivering excellent fade resistance in endurance racing conditions.
  • DS2500 – When it comes to track performance, dedicated race pads often yield exceptional results. However, the DS2500 brake pad stands out as a remarkable hybrid option suitable for both street and track use. It provides a moderate bite and exhibits good resistance to fading, while also offering manageable levels of dusting and noise compared to other street pads. In certain cases, there may be some squealing with specific vehicles when used in its intended role. If your needs include high-speed driving, canyon runs, or occasional light track use with road tires, the DS2500 is a highly recommended choice.
  • DS3.12 – Introduced in 2019, the DS3.12 is the latest addition to Ferodo’s impressive DS line of brake pads. Developed from the ground up to meet the rigorous demands of modern sports cars with increased power and aerodynamics, it sets new standards. The DS3.12 delivers exceptional performance for heavier vehicles that require stickier tires. Extensive testing has shown that it maintains a remarkably consistent torque curve across a wider range of temperatures compared to other pad compounds from various manufacturers. This ensures consistent braking even in high-temperature conditions, reducing wear rates without excessive damage to the discs. The DS3.12 also exhibits higher friction coefficient (mu) properties, requiring less pedal pressure for consistent unfaded performance in hotter temperatures. With its revolutionary design, the DS3.12 is poised to become the benchmark after rigorous testing.
  • DSUNO – If you value the effectiveness of the DS1.11 brake pads but desire increased stopping power, the DSUNO pads are worth considering. While these pads may have a shorter lifespan compared to the DS1.11, they offer a higher peak friction coefficient (mu) once they reach their optimal operating temperature on the track.
• Pad Tension Clips (frequently referred to as anti-rattle clips) are NOT included with these Competition Kits, but they do offer them as an option if you’re concerned about NVH.
  • The AP Racing calipers featured in this system offer a notable advantage: they are designed to accommodate brake pads from various manufacturers. Each manufacturer has its own specific pad dimensions, resulting in slight variations. As a result, pads from different manufacturers or even different batches may fit the calipers differently. Some pads may fit tightly, while others may have more play and potentially generate noise. To address this issue, Essex has developed the Essex Designed Pad Tension Kit. This kit is specifically designed to reduce pad movement inside the caliper, minimizing associated noise and providing a quieter braking experience. It’s important to note that each caliper requires one Pad Tension Kit, and a complete set of calipers would require two kits.

Applications

• 2009-2021 Nissan 370Z – Z34
  • Application Type – Track
• 2023+ Nissan Z – RZ34
  • Application Type – Track

About AP Racing / Essex

In 1981, Michael Gue relocated to Essex, Connecticut, and established a business called “Essex Racing” to cater to the demand for British road racing cars and car parts in the United States. Having previously worked with similar materials in England, this experience likely influenced his decision to move countries and pursue business opportunities in America. Essex Racing quickly gained a loyal fanbase and became a trusted source for racing products.

In 1983, Essex Racing relocated to Atlanta, Georgia, seeking a warmer climate. The company continued to thrive as an importer of Van Diemen and Tiga formula and sports racing cars. Essex Racing actively participated in SCCA (Sports Car Club of America) and IMSA (International Motor Sports Association) road races, achieving success in both professional and amateur competitions throughout North America.

The growing interest in Essex’s racing vehicles led to an increased demand for related spare parts. To meet this demand, Essex Parts Services was established in 1992 as a dedicated business for selling these components. Over the next decade, Essex Parts Services became one of the leading distributors of racecar and stock car accessories in the United States.

In 1999, Michael Gue departed from the business, and Richard Martin and Ken Gordon took over Essex Parts Services. The company continued its success, leading to its relocation to Charlotte, North Carolina, in 2004 to better serve its substantial stock car clientele.

Throughout its history, Essex has remained attentive to its clients’ needs and has evolved accordingly. While the product range has significantly changed over the past 35 years, the company’s core principles have remained unchanged. Today, Essex stands as a prominent supplier of top-quality parts and services for road race, stock car, and high-performance street drivers across North America.