Essex AP Racing Radi-CAL Competition CP9660/355mm Front Brake Kit Subaru WRX STI 2004-2021

Radi-CAL is a blanket term used to describe AP Racing's patented asymmetrical brake caliper design. Radi-Cal technology is grounded in Computer Aided Design (CAD) and Finite Element Analysis (FEA), and allows for organic, alien-looking designs that are a radical departure from conventional caliper designs of the past. Radi-CAL's are widely considered the pinnacle of current brake caliper technology. Since their inception in 2007, these revolutionary calipers have amassed a lengthy string of race victories at all levels of professional motorsport, while redefining brake performance expectations. For more details on the design concept and what these calipers have achieved in professional racing.

It has taken eight years, numerous generations of the design concept, and advancements in manufacturing techniques, but the Radi-CAL has finally evolved into a viable solution for racers and enthusiasts of all levels and budgets. While many products are supposedly born in racing, there can be no doubt about the Pro5000R pedigree. These calipers are direct descendants of the current crop of F1 and Sprint Cup calipers. They don't look ordinary, because they're not ordinary. They're the epitome of pure racing design: elegant, sparse, and brutally effective. And while they embody and employ the Radi-CAL design philosophy of the past, they also add some outstanding new features that enhance their practicality, convenience, and appeal. Quite simply, they are the lightest, stiffest, and most technologically advanced brake calipers that have ever been within the average enthusiast's grasp.

These intricate calipers have traditionally been machined from proprietary aluminum alloy billets. As one can imagine, machining away all of that material to achieve the final form is both time-consuming and costly. As a result, the price of these calipers has historically been prohibitive for the average club racer, time-trialer, or HPDE participant. Fortunately, the Pro5000R calipers use a new drop-forging technique that has dramatically lowered the manufacturing cost and the resulting price of entry, bringing this incredible technology to the masses.

Kit Includes:

• One pair AP Racing CP9660 Radi-CAL Pro5000R racing calipers
• One pair 355x32mm AP Racing CP5773, 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

• Features AP Racing CP9660 Radi-CAL six piston calipers
• 355x32mm, 72 vane AP Racing disc
• Eliminates approximately 10 lbs. of unsprung weight from the car's nose
• 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

• Brake pads are NOT included with our system. Racing brake pads are a highly personal choice. Many manufacturers include a set of inexpensive, low quality pads with their brake kits. Rather than artificially inflating the price of our system with a set of pads you probably don't want anyway, we've decided to remove the cost from our system and allow our customers to choose the pads that best suit their needs/wants. When purchasing our kit, you are able to choose one set of front pads at a substantial discount vs. the retail price. Please use the drop-down menu to select your pads.
• Pad Tension Clips (frequently referred to as anti-rattle clips) are NOT included with our Competition Kits, but we do offer them as an option if you're concerned about NVH. One of the great benefits of the AP Racing calipers in our system is that they are designed to accommodate pads from a wide range of manufacturers. Each manufacturer builds their pads with specifications that are slightly different. As such, pads from different manufacturers, or even from different batches, won't always fit in the calipers in exactly the same manner. Some pads are a snug fit, while others may rattle around and produce noise. The Essex Designed Pad Tension Kit is designed to dramatically reduce pad movement inside the caliper, along with just about all resulting noise. Click here to add the pad tension kits for the CP9660 calipers in this brake kit to your shopping cart. Please note that each caliper requires one Pad Tension Kit. If you need enough tension blocks for both of your calipers, you need to order two of these kits!