AP Racing ⨉ Essex CP9660 Radi-CAL ENP Competition Front Brake Kit for RZ34 Nissan Z

AP Racing ⨉ Essex CP9660 Radi-CAL ENP Competition Front Brake Kit for RZ34 Nissan Z

Revolutionize your RZ34 Nissan Z’s braking performance with the AP Racing ⨉ Essex CP9660 Radi-CAL ENP Competition Front Brake Kit. Experience unprecedented weight savings with a reduction of over 25 unsprung lbs. from the nose of your car, despite the kit’s significantly larger size compared to OEM brakes. Precisely designed to fit neatly inside popular 18″ wheels, this kit showcases AP Racing CP9660 Radi-CAL calipers finished in a jewel-like ENP coating that is not only strikingly durable, but also effortless to clean. The kit incorporates 372x34mm, 72 vane AP Racing J Hook 2-piece floating discs, and each of its components are engineered to withstand the heat of prolonged track sessions. With pistons appropriately sized for seamless integration with the OEM master cylinder and ABS system, this kit is designed to collaborate flawlessly with either the OEM rear brakes or their corresponding AP Racing by Essex Rear Brake Kit. Transform your ride into a track-ready powerhouse with this unmatched front brake kit.

Radi-CAL

• With its patented Radi-CAL asymmetrical brake caliper design, AP Racing has significantly advanced the field of brake technology. This innovative design employs state-of-the-art technologies, such as Computer Aided Design (CAD) and Finite Element Analysis (FEA), enabling the creation of uniquely designed calipers that go beyond traditional norms. Radi-CAL calipers, celebrated as the zenith of brake caliper technology, employ a distinctive and organically-shaped design that heralds a new era of innovation. Introduced in 2007, they have consistently redefined expectations, demonstrating their superb performance on numerous professional motorsport race tracks. With an impressive tally of victories, Radi-CAL calipers have indelibly marked their presence as a transformative force in brake performance.
• Benefits of the Radi-CAL Design
  • Significant Stiffness Enhancement – The Radi-CAL calipers demonstrate an impressive improvement of over 30% in both static and dynamic stiffness compared to conventional calipers. This significant enhancement in stiffness minimizes deflection under load, resulting in superior pedal feel and modulation, uniform pad wear, and extended caliper service life.
  • Substantial Weight Reduction – Through the elimination of unnecessary caliper mass, the Radi-CAL design effectively reduces the overall weight of the caliper, despite the notable increase in stiffness.
  • Optimized Airflow – The Radi-CAL calipers are meticulously engineered to optimize airflow, facilitating efficient circulation of air around and through the caliper. This enhanced airflow enables superior heat dissipation and cooling, thereby elevating overall brake performance.
  • Efficient Packaging – With its asymmetric caliper profile and internal fluid porting, the Radi-CAL caliper is purposefully designed to fit into compact spaces with efficiency. This thoughtful design allows for more flexible installation options without compromising performance.

CP9660 PRO5000R Calipers – The Everyman Radi-CAL

• After eight years of development, multiple design iterations, and advancements in manufacturing techniques, the Radi-CAL has finally evolved into a practical solution suitable for racers and enthusiasts of all levels and budgets. While many products claim to have racing origins, the Pro5000R calipers undeniably possess a genuine racing pedigree. Directly descended from the current generation of F1 and Sprint Cup calipers, they stand out from the ordinary because they are anything but ordinary. These calipers epitomize pure racing design, with an elegant, minimalist aesthetic that delivers brutal effectiveness. While they embody the past Radi-CAL design philosophy, they also incorporate exceptional new features that enhance practicality, convenience, and appeal. In essence, they are the lightest, stiffest, and most technologically advanced brake calipers ever accessible to the average enthusiast.
• Traditionally, these intricate calipers were machined from proprietary aluminum alloy billets. However, the process of machining away all that material to achieve the final form was time-consuming and expensive. Consequently, the price of these calipers has historically been prohibitive for the average club racer, time-trialer, or HPDE participant. Fortunately, the Pro5000R calipers utilize a new drop-forging technique that has significantly reduced manufacturing costs and, subsequently, the entry price. This development has made this incredible technology accessible to a wider audience.

Radi-CAL = Massive Dynamic Stiffness Increase

• Over the years, several strategies have been employed to reduce the size of brake calipers while maintaining sufficient stiffness. These strategies encompassed robust caliper bridge designs, two-piece calipers with steel through-bolts, the utilization of exotic materials such as Beryllium and MMC, the shift from casting to forging, and the adoption of monobloc designs. These innovations aimed to make calipers lighter, smaller, and stiffer. However, the traditional rectangular, boxy shape remained the widely accepted standard for calipers.
• AP Racing has challenged this notion, questioning the efficiency of the rectangular box design for brake calipers. They have demonstrated that the conventional design is suboptimal. As a caliper clamps brake pads against a spinning disc, a significant tangential friction force is generated between the pads and the disc. This force pulls the caliper strongly towards the spinning disc. The caliper resists this force through the rigid mounting points on the spindle.
• During braking events, the dynamic load exerted on the caliper causes it to twist or deform into a parallelogram shape. AP Racing recognized the significance of this dynamic force and specifically 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 intentionally designed 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 support the forces acting on it during braking, rather than relying solely on an empty box structure. By redistributing the mass, significant overall weight reduction is achieved by eliminating non-essential, non-load-bearing material from the caliper 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 mentioned earlier, the Radi-CAL design philosophy not only focuses on what is present but also on what is absent. The design deliberately redistributes caliper mass, creating voids in unconventional areas. This strategic removal of mass from the caliper body optimizes its overall size, resulting in an impressively lightweight and compact footprint. While competing six-piston calipers typically weigh between 9 to 12 lbs, the CP9668 weighs an astonishingly low 6.8 lbs.
• Essex’s approach to brake kit design has always prioritized efficiency, recognizing that anything larger than necessary adds unnecessary weight. The Radi-CAL aligns perfectly with this philosophy. Many brake packages in the market face the challenge of wheel fitment. They feature oversized discs and 12-piston calipers, which can pose difficulties when trying to fit them behind OEM wheels or lightweight alternatives. The goal is to save unsprung weight and enable the use of smaller, lighter wheels that are more easily accessible and cost-effective when paired with R compound tires. Properly designed components that prioritize performance eliminate the need for excessively heavy calipers. Concerns about stiffness resulting from mass reduction are unfounded. AP Racing’s Pro5000R calipers are not only lightweight but also exceptionally stiff, purpose-built for racing applications.
• A notable feature of the Pro5000R range is the positioning of the bleed screws and fluid pathways. The 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 crafted through machining a single, solid block of exclusive aluminum alloy, employing a design known as monobloc. With this design, the piston bores and piston seal grooves can only be 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 laborious and costly process. As a result, monobloc Radi-CAL calipers have been priced beyond the reach of the average club racer, time-trialer, or HPDE participant. However, the advent of a novel two-piece drop-forging process has turned the Pro5000R caliper into a reality. This innovative manufacturing technique allows conventional machine tools direct access to the piston bores, resulting in a significant reduction in production time and cost while still upholding an exceptionally rigid structure.

ENP (Electroless Nickel Plated) Finish

• A notable drawback of typical aftermarket calipers is their finish. Most aftermarket calipers are coated with paint, whether it be red, black, or gold. The purpose of this painted finish is to provide an attractive appearance and prevent corrosion in harsh winter conditions. However, when these painted calipers are subjected to track environments, various issues arise, including chipping, flaking, fading, color shifting, and overall deterioration of the finish in a relatively short period of time. In some cases, even OEM calipers can change color from their original shade to an unattractive brown in just one weekend. While some may perceive this wear as a symbol of pride, the reality is that it does not maintain an appealing look. Additionally, the particles from the paint can end up in unwanted areas, as we will discuss shortly.
• The primary culprit behind these issues is heat. Paint and powder coat finishes are ill-equipped to handle the high temperatures experienced on the track. Powder coat finishes, in particular, are prone to problems with shrinkage. When the caliper is heated, the powder coat layer expands and enlarges, but it may not shrink in tandem with the caliper body when it cools down. As a result, the loose shell of finish cracks and deteriorates.
• Paint can also face similar issues depending on its application. If you were to compare several aftermarket calipers from the same manufacturer, you would likely observe slight variations in the painted finish. 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 precise and controlled environment, and without it, variations in the application are bound to occur. A thick coat of paint can give the part a soft appearance and is 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 undergo noticeable color shifting when exposed to heat. Red can turn into maroon or black, gold may transform into brown, and black simply becomes less visually appealing.

Ventilated, Domed Back, Stainless Steel Pistons

• There is a debate among individuals regarding the use of aluminum pistons in track calipers, with some arguing that the expansion rates of the pistons and caliper body should be the same 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 excel in creating a thermal barrier that effectively minimizes heat transfer to the brake fluid, preventing a soft pedal caused by fluid fade on the track. This superiority has been consistently demonstrated across various levels of motorsport. While many aftermarket calipers utilize pressed aluminum pistons, the Pro5000R calipers employ meticulously machined stainless steel pistons, despite the higher cost associated with them.
• To enhance piston stiffness, AP Racing has incorporated a domed shape at the back of the piston. Although it may seem like a small design element, the introduction of domed back pistons in professional racing received immediate and overwhelmingly positive feedback from drivers. The domed back significantly increases stiffness, resulting in a palpable improvement felt through the pedal. As a result, this design has become the benchmark against which all other designs are measured.
• For enhanced heat resistance, the pistons are equipped with ventilation. The presence of air gaps around the edges of the piston 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 utilize stainless steel pistons that incorporate anti-knockback (AKB) springs, which may come as a surprise to some. However, these springs serve a crucial purpose. If you have ever experienced your pedal dropping after a series of S-turns when entering a brake zone, you have encountered knockback, which can be quite unsettling. Professional drivers often lightly tap their brakes before a brake zone to counteract knockback.
• 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. The extent of knockback depends on the vehicle and the amount of deflection in these components. As the brake disc deflects, it pushes the brake pads apart, resulting in the caliper pistons retracting into their bores. However, the piston seals do not possess sufficient tension to fully return the pistons to their original position, leading to slack within the system. When the brake pedal is applied, it continues to drop until the slack is taken up.
• Anti-knockback springs help 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. As a result, there is less pedal drop and fewer nerve-wracking moments when approaching heavy brake zones.
• The inclusion of lightweight AKB springs does not pose significant downsides as long as the caliper is designed to accommodate them. Specifically, AKB springs do not cause increased drag or wear on the pads and discs, provided that the shape and material of the piston seals are appropriately considered.
• During driving, as the suspension compresses, the disc moves laterally, and the pads are slightly pushed away from the disc. It is helpful to think of the seals in the caliper as a spring or hinge attached to the side of the piston, rather than just a ring through which the piston slides. In an AP Racing competition caliper, the groove where the seal resides is not a square-cut groove; it features angles. As the pistons slide in or out, friction occurs between the outer piston wall and the seal, causing the seal to deform slightly.
• A certain amount of tension or friction must be overcome before the piston starts moving through the seal ring. This tension/friction prevents the piston from dragging on the disc once the pistons are pushed back into the bores due to disc/suspension movement.
• With the inclusion of AKB springs, slightly more force is required to push the pistons back into their bores compared to without the springs. Once the spring is compressed, it unloads and pushes the piston back to the ‘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. The seal provides this initial friction to limit movement, and the spring adds additional resistance. Consequently, properly designed AP Racing calipers do not drag or cause unnecessary wear.

High Temperature, Low Drag Seals Without Dust Boots

• Essex often receives an unexpected question from prospective customers regarding the maintenance and rebuilding of calipers in their kits due to the absence of dust boots on the pistons. This question perplexes them because it lacks intuitive reasoning. If a product is specifically designed to withstand the extreme high-heat conditions of track use, it should require less maintenance compared to brake components intended for low-speed and low-temperature street driving.
• There is often confusion between piston seals and dust boots. All calipers feature seals, which are the small rubber rings inside the piston bores. These seals 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 employ high-temperature seals identical to those used in NASCAR Sprint Cup, ALMS, DTM, and other professional racing series. These high-temp 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.
• Most aftermarket calipers are designed for year-round road use and come equipped with external dust boots, as illustrated in the example below. These rubber boots stretch as the pistons extend, aiming to keep contaminants out of the piston bore. While this concept may seem appealing, Essex has observed instances where customers have burned through these boots in a single 20-minute track session. Once this occurs, 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 design, eliminating the mess they create.

Simple Pad Change with Two Bolts

• When the time comes to replace your brake pads, it’s natural to feel less than enthusiastic about the task at hand. However, with the Pro5000R calipers, this process becomes effortless. Bid farewell to struggling with hammers, punches, or pliers. AP’s bridge bolts 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 relishing the exhilaration of driving.

Pistons Sized Specifically for Your Car

• The brake systems are meticulously designed with piston sizes that closely align with the OEM brake torque for a specific axle. This ensures that front systems can be seamlessly installed on stock cars without any detrimental effects or negative implications for the ABS system. There is no requirement to replace the stock master cylinder or the OEM rear brake system.

Lifetime Professional Reconditioning Service

• Essex is recognized as the official AP Racing caliper reconditioning center in North America. Their team of highly skilled service technicians specializes in the meticulous rebuilding of numerous AP Racing calipers each year. These calipers are entrusted by top teams in motorsport, including those in NASCAR Sprint Cup and ALMS, highlighting Essex’s expertise and reputation in the industry.
• Removal and Shipping – Simply detach your calipers from the vehicle, drain and clean them, and send them back to Essex for service.
• Hardness Testing – Upon disassembly, your calipers undergo Rockwell hardness testing to assess their fatigue and stiffness degradation. This test enables us to evaluate the extent of wear and determine whether the calipers should be rebuilt or replaced. Fatigued calipers can result in issues like pad tapering, increased pad wear, seal leakage, and diminished pedal firmness.
• Ultrasonic Cleaning – Calipers that pass the hardness test undergo a thorough cleaning process in Essex’s advanced ultrasonic cleaner. This state-of-the-art cleaning method removes all dirt, debris, and brake fluid, delivering results that surpass traditional hand-cleaning methods.
• Inspection and Re-Assembly – All serviceable components of the caliper, including seals, abutment plates, pistons, and bleed screws, are carefully inspected and replaced as necessary to ensure optimal performance.
• Cyclical Pressure Testing – Once the calipers are rebuilt, they undergo stringent cyclical pressure testing on a specialized bench. This testing procedure ensures proper functionality and identifies any potential leaks that may occur only under specific pressure conditions.

Discs – AP Racing Competition J Hook

• The AP Racing J Hook discs included in this system are the epitome of endurance racing excellence. These top-tier components are specifically designed to endure the harshest conditions you can subject them to. Renowned for their remarkable durability, these discs boast a proven track record in professional racing, having clinched countless victories and championships in esteemed events such as ALMS, Rolex, Grand Am, and others. With their exceptional performance and established reliability, the AP Racing J Hook discs serve as the ideal companion for drivers who prioritize exceptional performance and long-lasting endurance in their racing pursuits.

Two-Piece Floating Design with Aluminum Hat

• When exposed to heat, iron brake discs, like most metals, undergo significant expansion. This expansion leads to an increase in the diameter and circumference of the disc. One-piece disc designs face a challenge in accommodating this expansion. In the image below, imagine the disc being heated during track use. As the disc expands, the outer edges pull away from the center without any provision to accommodate this expansion. Consequently, the edges of the disc become distorted and lifted, resulting in a phenomenon known as coning. Now envision the disc mounted vertically in your caliper. Coning directly impacts the contact between the brake pads and the disc, leading to uneven wear, tapering, and a prolonged brake pedal.
• In contrast, two-piece discs are specifically engineered to compensate for disc expansion when subjected to heat. This compensation is achieved by incorporating “float” into either the disc itself or the disc hat/bell. In the example below, the float is integrated into the disc. If you closely observe the picture, you’ll notice that the mounting holes for the hat attachment bobbins are not circular but oblong in shape. These channels allow the hat mounting hardware to slide as the disc heats up and expands. This enables the disc to maintain its proper position within the caliper without distortion. This design approach effectively minimizes distortion, stress cracks, and pad taper, ensuring optimal performance and long-lasting durability of the braking system.

Mounting Hardware and Anti-Knockback Spring Clips

• When closely examining the mounting hardware used in Essex’s Competition Kits, you’ll discover several often overlooked details that distinguish them from inferior products. These components are purposefully designed and not simply generic bolts sourced from a local retail store. They are custom-made in the USA exclusively for Essex and AP Racing, the very same components utilized in professional racing applications.
• As mentioned earlier in reference to the piston springs, knockback can present a significant concern when driving on the track. To effectively manage the lateral movement of the disc, which can push the pistons back into the caliper, we incorporate anti-knockback spring clips at every alternate disc attachment point. For example, a ten-bolt disc assembly would include five spring clips, while a twelve-bolt disc would feature six. These spring clips serve to maintain alignment between the disc hat and the iron ring while allowing for radial expansion and floatation of the disc. Additionally, they provide the added benefit of preventing any rattling or noise originating from the disc hat and iron disc assembly.

Hat Design

• Apart from their other notable advantages, floating two-piece discs offer the additional benefit of minimizing heat conduction to the hubs and bearings. This reduction in heat transfer helps mitigate wear and tear on these valuable components, ultimately contributing to their extended lifespan. The disc hats, an integral part of the assembly, are meticulously crafted from 6061 heat-treated billet aluminum, ensuring exceptional strength even under high-temperature conditions. To further enhance 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 are designed with scallops on the underside, facilitating effective heat dissipation along the outer face of the disc once they are installed.

Internal Vane Quantity and Quality

• The internal vane design of AP J Hook discs distinguishes them from OEM-style discs and other aftermarket brands. Unlike the pillar vane designs found in many OEM discs, AP Racing discs employ a different approach. Pillar vanes consist of interconnected posts or pillars that join the two halves of the disc, causing turbulence as air passes through. This design primarily focuses on disc face stability and cost efficiency, rather than efficient heat evacuation. Another type of vane design seen in some 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 feature directional vanes that optimize airflow by spinning in a specific direction, maximizing the amount of air 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 precisely engineered to promote smooth airflow and enhance cooling performance.
• Furthermore, AP Racing discs surpass many aftermarket discs in 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 facilitates higher airspeed, improved heat transfer, reduced air recirculation between vanes, and diminished deflection at the disc face. Compared to OEM-style or competitor’s 48 vane discs, the 60+ vane discs offered by AP Racing demonstrate enhanced resistance to coning, distortion, and cracking. They also deliver benefits such as reduced brake fade, minimized judder, more consistent pad contact, and extended service life.
• A comparison of the internal vane design reveals the distinctive features of the AP Racing J Hook disc. Notably, the AP Racing disc exhibits 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 contributes to superior airflow performance.
• It is important to note that most cooling air entering a brake disc originates from the back side of the discs, especially 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, whereas the OEM discs feature narrower inlet ports and potential obstructions hindering the flow. Consequently, the AP Racing disc maintains significantly lower temperatures, reducing the likelihood of cracking and wear.

Exclusive AP Racing J Hook Slot Pattern

• When modifications such as slots or holes are introduced to a brake disc, they can impact heat transfer. These modifications create cool spots around the slots or holes when the disc heats up, which is not ideal. Ideally, heat should be distributed uniformly across the disc to allow for effective cooling by airflow and radiation. The presence of cool spots can lead to areas of stress concentration and increase the likelihood of disc cracking. Additionally, cool spots cause uneven distortion of the disc’s face, resulting in uneven pad deposits, vibrations, and judder.
• OEM discs address this issue by leaving the disc face blank, avoiding the formation of cool spots. While this 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 competitive aftermarket discs feature straight slots, which tend to create cool spots across the disc face between the slots.
• Extensive research and development testing conducted by AP Racing has resulted in the development of the J Hook design, which 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 to promote even heat distribution and distortion. In addition to reducing the risk of cracking, the even heating of the disc promotes the formation of a uniform transfer layer of pad material during the bedding-in process.

Complex Metallurgy Developed Through 50+ Years of Experience

• With over five decades of experience in the design of brake components, AP Racing boasts an impressive track record. Their components have been utilized on cars that have triumphed in over 750 Formula 1 races, a testament to their expertise and reliability. In fact, during any given race weekend, you will find AP J Hook discs gracing 75% or more of the NASCAR Sprint Cup grid.
• Drawing upon this extensive experience, AP Racing has developed a proprietary iron alloy renowned for its exceptional durability. This alloy is meticulously crafted to endure the rigorous conditions to which it will be subjected. Unlike OEM discs that prioritize cost-effectiveness and ease of production, AP Racing’s disc design objectives are distinct. Their unwavering focus lies in delivering superior performance and unwavering reliability, ensuring that their products can withstand the most demanding usage without compromise.

Caliper Brackets & Hardware

• The caliper brackets provided in our kit are meticulously machined from heat-treated 6061 T6 billet aluminum, renowned for its exceptional strength and durability. To further enhance their resilience, the brackets undergo a rigorous hard anodizing process. We uphold the same high standards utilized in professional racing, utilizing aircraft-grade hardware that meets stringent quality requirements.
• One notable advantage of their brackets lies in their thoughtfully designed cutaway feature. This design allows for precise fitting of various brake duct kits currently available in the market. The cutaway design ensures a precise and secure fit, facilitating efficient cooling and airflow to the brakes—an essential element for achieving optimal performance on the track.

Brake Ducting

• Essex advises against the use of aftermarket brake ducts in conjunction with their Competition Brake Kits. Through extensive experience, they have encountered limitations in packaging that make it extremely difficult to achieve effective airflow from the front of the car to the center of the brake discs. The narrow diameter of the duct hoses and limited space within the fender well often pose challenges in installing properly-sized hoses that can provide sufficient cooling. Additionally, 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.
• Furthermore, the plates used to attach brake ducts at the wheel hub can inadvertently trap heat against the inner disc face, leading to overall increases in system temperatures. Considering these factors, 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 features 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 sandwiched in between.

Spiegler Stainless Steel Brake Lines

• The Competition Kits include premium stainless steel brake lines, known for their outstanding quality. Spiegler lines excel in comparison to other options on the market, offering a wide range of features that deliver unparalleled performance benefits.

Disc Burnishing / Bedding Service

• Neglecting proper preparation before taking your brake discs on the track can lead to issues such as juddering, vibration, and cracking. However, conducting the necessary preparations at the circuit can be challenging, as it consumes valuable practice time and can pose hazards to other drivers in close proximity. Additionally, on-track preparations lack consistency due to external factors like changing weather conditions or traffic, which can hinder the repeatability required for optimal bedding and consistent performance.
• To address these concerns, Essex now offers a professional burnishing service to all customers. Originally reserved for their racing clientele, this service allows individuals to have select Competition Brake Kits pre-burnished at Essex’s facility. With years of experience servicing discs for elite teams, Essex’s skilled technicians use 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 burnish the discs in the pad compound of your choice, ensuring the benefits of the procedure while using the pads provided in your kit.

Features

• Saves 25+ unsprung lbs. from nose of the car vs. OEM brakes, despite being considerably larger than stock.
• As large as possible while still fitting inside popular 18″ wheels.
• Features AP Racing CP9660 Radi-CAL calipers.
• Jewel-like ENP caliper finish is incredibly durable and easy to clean.
• 372x34mm, 72 vane AP Racing J Hook 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 OEM rear brakes or their AP Racing by Essex Rear Brake Kit.

What’s In The Box

• One pair AP Racing CP9660 Radi-CAL Pro5000R six piston calipers in ENP Finish (Electroless Nickel Plated).
• One pair 372x34mm AP Racing CP7177, 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.
  • Choosing the right racing brake pads is a personal decision. While some manufacturers include low-quality pads with their brake kits, Essex takes a different approach. Instead of including pads that may not meet your preferences, they have removed the cost of pads from their system. This allows customers to select the brake pads that best suit their specific needs and desires. When purchasing this kit, you have the opportunity to choose one set of front pads at a significant discount compared to the retail price. This ensures that you can tailor your brake setup to your liking without any unnecessary expenses.
  • DS1.11 – The DS1.11 brake pad is known for its moderate performance in endurance racing compounds. It offers a lower mu (friction coefficient) compared to the 3-12 pad, requiring more pedal pressure. However, as temperatures rise, the DS1.11 provides drivers with declining torque, allowing for better control with street tires. While it may not last as long due to its less aggressive interaction with discs, it still offers impressive maximum temperature resistance. Its reputation is largely based on the sensation it provides, with good fade resistance in endurance racing conditions.
  • DS2500 – For track performance, dedicated race pads tend to offer superior results. However, the DS2500 brake pad is an exceptional hybrid option suitable for both street and track use. It provides moderate bite and good resistance against fading, while also offering manageable levels of dusting and noise compared to other street pads. In some cases, there may be some squealing with certain 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 hard to beat.
  • DS3.12 – Released in 2019, the DS3.12 is the latest addition to Ferodo’s impressive DS line of brake pads. Designed to meet the high demands of modern sports cars with increased horsepower and aerodynamics, it was created from the ground up. The DS3.12 provides exceptional performance for heavier cars that require stickier tires. Testing has shown that it offers a remarkably flat torque curve across a wider range of temperatures compared to other pad compounds from various manufacturers. This means that braking remains consistent even in high-temperature conditions, reducing wear rates without excessively damaging discs. It also has higher mu properties, requiring less pedal pressure for consistent unfaded performance in hotter temperatures. With its revolutionary design, the DS3.12 sets a new standard and is likely to be considered the gold standard after thorough testing.
  • DSUNO – If you appreciate the effectiveness of the DS1.11 brake pads but desire increased stopping power, the DSUNO pads are worth considering. While these pads may not provide the same longevity as 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 included in this system offer a significant advantage: they are designed to accommodate brake pads from various manufacturers. Each manufacturer has its own specifications, resulting in slight differences in pad dimensions. Consequently, pads from different manufacturers or even different batches may not fit the calipers in the exact same manner. Some pads may fit snugly, while others may have more movement and produce noise. To address this issue, Essex has developed the Essex Designed Pad Tension Kit, which is specifically designed to reduce pad movement inside the caliper and minimize associated noise. This kit effectively addresses the problem of pad rattling and ensures a quieter braking experience. It is important to note that each caliper requires one Pad Tension Kit, with two kits needed for a complete set.

Applications

• 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.