Tags Posts tagged with "Brakes"



AP Racing World Radi-CAL II Calipers

Where do they come from?

These brakes may look alien but they come from the master minds in the engineering department at AP Racing.  In 2007 AP Racing revealed the original World Radi-Cal brake calipers to the world at Watkins Glen on Tony Stewart’s NASCAR race car.  He went on to win the race crediting his brakes with giving him the upper hand over his competition.

In fact, they were so dominant that NASCAR actually outlawed the brakes until all of the other teams were able to have equal access to them!  Since then the race spec calipers have become the spec calipers used on DTM touring cars, Aussie V8 super cars as well as filling out most of the Formula One field and sports cars around the world including LMP1.

When AP Racing were thinking of developing a new caliper they decided to take a very unusual approach… They started with a blank sheet of paper.  They did not want to rely on “what they knew” and instead they wanted to test themselves, their finite element analysis software and challenge themselves to reinvent what a brake caliper is.


During their testing and development they used an FEA analysis software that is common in the engineering world.  However, they quickly realized that FEA analysis software is designed to introduce a static load and the intense environment of a braking system is far from static.  The heat generated, the RPM of the rotor, the modulation of the brake pedal, all of these factors and more equate to a very dynamic environment that can’t be treated like a traditional mechanical part.

AP Racing knew that the only way to move forward was to develop their own proprietary FEA analysis software.  AP Racing began working on developing a software that could replicate the incredibly diverse and ever changing environment that is a braking system.

During their initial testing the AP Racing engineers recognized that the friction between the brake pads and rotors was literally trying to rip the caliper from its mounts.  In a static environment the only way to test the rigidity of a caliper is to introduce a pressure and measure the amount of flex in the caliper.  This flex is basically how much the caliper expands horizontally.

During their dynamic testing they noticed that the caliper was actually twisting diagonally due to the forces created by the RPM and mass of the rotor interacting with the friction created by the application of the brake pads.  The solution was to reinforce and stiffen the caliper in key locations to counteract this force.  In turn, AP Racing realized that they could remove material that was unaffected by these forces.  The end result is an asymetrical design that is incredibly stiff yet also lightweight.  To further improve the rigidity of the caliper AP Racing implemented their patented “stiffening bands” which wrap around the caliper to form a “chassis” of sorts which ties all points together offering an even stiffer design.


AP Racing knew that the World Radi-CAL brake technology was the way of the future and that they needed to find a way to bring this technology to the road car market.  While race calipers offer a no compromise solution, they also mean higher prices and more regular service intervals.  AP Racing leaned on their expertise in developing a road car brakes for the Bugatti Veyron and Chiron as well as McLaren, Lotus, Holden, and more.  By applying their OEM manufacturing standards and test procedures AP Racing was able to launch the World Radi-CAL I road car calipers with STILLEN at the 2014 SEMA show.

These road car calipers employ all of the features of the race calipers but also add other features that make them suitable for daily driving as well as high performance environments.  Road car calipers are manufactured out of pressure forged aluminum.  This manufacturing process is less expensive than a Monobloc caliper which makes these fantastic brakes accessible to the average road car enthusiast.

Additionally, these calipers are equipped with dust seals which prevent road debris and dust from entering the hydraulic circuit or caliper pressure seal over time.  Road car calipers also feature anti-rattle clips to prevent any issues with pad knock back or residual noises.


Never ones to settle, AP Racing again went back to the drawing board to develop a range of calipers that would take even more from the racing world.  Enter, World Radi-Cal II.  World Radi-Cal II calipers offer the unique look and style that is associated with the Radi-Cal race brakes.  The goals for Radi-Cal II were simple: Make the caliper stiffer, lighter and look even more aggressive.  We are excited to say that each of those goals was achieved with unbelievable results.  The Radi-Cal II calipers also feature the superior stiffening bridge that not only ties the caliper together horizontally but also vertically by connecting the top and bottom of the caliper.  Even with this incredible rigid structure the design still allows for quick pad swaps that do not require removal of the caliper.


Further improvements were made to the calipers by removing additional material and pocketing around the calipers and non-structural areas of the caliper.  One of the benefits of removing this material is not only the weight savings but also the improvements with the unobstructed airflow around and through the caliper.  This airflow improves cooling and reduces overall operating temperatures.

Not only is World Radi-CAL II the most technologically advanced caliper ever made.  The aggressive design also makes it the best looking caliper available today.  World Radi-CAL II calipers are sure to draw attention with their unique futuristic styling and their performance numbers to back it up.

AP Racing World Radi-CAL II Big Brake Kit

  • AP Racing patented asymmetrical, forged aluminum WR2 6 piston brake calipers
  • 6061-T6 aluminum high strength bracket and billet aluminum rotor hats
  • DOT Compliant stainless steel braided brake lines
  • Designed to work with OEM brake master cylinder and ABS system
  • Unique scannable QR code for authenticity
  • 6 piston calipers are 150g lighter and 33% stiffer than Radi-CAL I calipers
  • 4 piston calipers are 100g lighter and 28% stiffer than Radi-CAL I calipers
  • Engineered to fit most 18 inch wheels (370mm rotor applications)
  • Toughest testing standards in the industry
  • Engineered for compatibility with OEM brake master cylinder and ABS systems
  • Finished in OEM quality red or black anti-corrosion finish

In 2014 STILLEN introduced AP Racing World Radi-CAL road car brakes at SEMA show which very quickly became recognized as the best aftermarket big brake kits available.  For the past 3 years our customers have been reporting back that the STILLEN AP Racing brakes are adding improved looks and style to the car as well as reducing lap times when used at high performance driving days!


AP Racing World Radi-Cal road car calipers take the features of the asymmetrical design, reinforced stiffening bands and pair them with a cost effective, strong and lightweight pressure forged aluminum manufacturing process to deliver superior results for the road car market.

Following on from the success of motorsports Radi-CAL™ brake systems, AP Racing has brought the same design philosophy to the road performance market in the form of the new World Radi-CAL II calipers.  These new pressure forged aluminum 4 and 6 piston calipers incorporate AP Racing’s patented technology allowing the road user to experience the superior performance that World Radi-CAL™ offers.

05_Header_3_Calipers_v2World Radi-Cal II calipers incorporate all the features demanded by the road performance market including boot type dirt seals, advanced anti-corrosion attractive paint finish and noise abatement solutionsCompared to WR1 calipers, WR2 calipers are stiffer (6-piston: 33% stiffer, 4-piston 28% stiffer) and lighter (6-piston: 150g lighter, 4-piston 100g lighter). Utilizing the latest FEA (finite element) analysis software and brake dynamometer testing, it was designed to implement the latest technologies learned through 40+ years of highly successful motorsports participation and an unparalleled 700+ F1 Grand Prix victories.

AP Racing pressure forged aluminum caliper bodies are tested at over 500,000 cycles of pressure and torque to meet AP Racing’s stringent OE and high performance road use validation testing to ensure maximum stiffness and durability required for use on road registered vehicles. The forged aluminum process was chosen as it offers a 25% stronger and lighter caliper than similarly sized units using a casting process. These larger, lightweight AP Racing calipers replace the typical heavy cast iron OE calipers that are designed for low cost and little regard to high performance driving.


The opposed piston design guarantees maximum stiffness for better pedal feel, modulation and immediate braking action from the drivers input. Four piston and six piston designs allow a larger pad area to be used which decreases heat at the friction point between the pad material and disc surface while maintaining the same brake torque. This single detail increases both rotor and pad service life. Additionally, a larger caliper aids in braking performance by acting as a more efficient lever on the rotor. This in turn applies more torque to the rotor thus increasing the force applied to the rotor.

The asymmetrical design achieves improved stiffness while also reducing weight by removing material where there is little dynamic load and relocating that material to areas that need additional reinforcement due to the dynamic forces that occur during high performance driving.  This revolutionary caliper design guarantees maximum stiffness for better pedal feel, modulation and immediate braking action from the drivers input.  Additionally, AP Racing WR2 calipers offer the largest pad possible.  The larger pad decreases heat by distributing the kinetic energy generated during braking across a larger surface area thus better controlling the thermal dynamics of your braking system.  Additionally, this larger piston/pad surface area applies superior clamping force to the rotor.  Furthermore, the larger diameter rotor allows us to move the caliper further out thus increasing the brake torque applied to the rotor assembly.


By controlling the operating temperature caused by the friction between the pads and rotor we are able to better manage the performance of the big brake kit. Controlling the temperature in a braking system is one of the biggest goals when engineering a system. A vehicle will create the same amount of heat when stopped from the same speed, the brake component choices will control how that heat is managed. Both pads and rotors have optimum operational temperature ranges. For a street car, we must make sure the brakes work flawlessly at sub-zero temperatures but still offer excellent performance when being pushed in a high performance environment and being pushed to their limits. All calipers are double sealed to protect piston bores and pressure seals from road debris. High temperature seal material is used to ensure safety at high temperature use. These seals are designed to minimize off brake pad drag on the disc which will increase pad and disc life.


Light weight, improved rigidity and better cooling characteristics than other competitions’ conventional brake caliper designs.  AP Racing World Radi-CAL™ concept represents a major innovation in braking technology.



The AP Racing discs in the Radi-CAL big brake kits are directionally curve vane vented for maximum air flow through the disc. AP Racing’s unique curve vaned discs are Dyno and race proven as the best designed rotors for optimized cooling. The curve vane rotor acts as an air pump pulling air into the center of the rotor and blowing it through the veins and out of the top of the rotor. This act allows the rotor to be self-cooling and work extremely efficiently.01_Header_Rotor_v1

AP Racing’s Wide Disc Technology (WDT) is used for the most efficient way to transfer heat to from the disc. Designs using wider discs with larger air gaps increase air flow rates within the discs as proven by AP Racing’s FEA, CFD and TSA testing. This goal was achieved while also  decreasing disc weight and  disc stress as well as  decreasing disc temperatures by up to 300 degrees F.


Larger two piece rotors allow for greater thermal capacity with an eye on weight by using aluminum center bells (hats) that minimize the unsprung weight of the overall disc assembly. This means greater heat management without increasing corner weight. It also increases the effective radius (leverage point) of the brake system which creates more brake torque with same braking effort.

Floating rotor assembly hardware is used to allow the brake disc and bell (hat) to move freely radially and axially to allow the disc to expand and contract under thermal stress without  binding or cupping. This allows the disc to stay centered to the caliper and reduces pad knock back. STILLEN utilizes McLaren tension springs on all floating assemblies to reduce any noises or rattles and to meet our NVH standards.


Lightweight billet aluminum bells (hats) are made vehicle specific to match the OE bell (hat design) for a perfect match to the OE hub. For the AP Racing Radi-CAL brakes STILLEN has selected an aircraft grade 6061-T6 billet aluminum. This is the same material used by AP Racing in their aluminum hats.   6061-T6 aluminum is considered the standard aluminum used in all aerospace applications and offers excellent strength and durability along with excellent longevity and service life.  Caliper and rotor location is optimized during the hat and bracket engineering phase by moving the caliper and rotor as far inboard to the wheel well as possible.  This ensures that AP Racing by STILLEN big brake kits fit the widest range of wheels possible.


“Industry standard” is to use a 10 point bolt pattern to connect the rotor and hat assemblies.  AP Racing and STILLEN have chosen to go with a 12 point bolt pattern configuration.  This means that the stresses and loads put on the braking system is distributed more evenly across both the rotor and the hat thus reducing the stress and fatigue placed on the system components.

  • All kits feature 2 piece full floating rotors for lightweight and high durability
  • All rotors are available in either J hook or cross drilled slotted patterns
  • Rotors feature AP Racing wide disc technology to allow for better cooling and longer service life
  • Directional vanes are used in every rotor to allow optimal airflow and cooling efficiency

Performance Brake Pads

The friction material used in the brake system is a key factor for the overall performance of the system. There are many variables to consider including pad material heat range, dust, NVH (noise, vibration and harshness) issues and of course performance characteristics. Most OE and aftermarket brake pad materials concentrate on low dust and NVH issues while sacrificing performance levels. AP Racing and STILLEN consider all four points in the selection of the supplied brake pad material.


The result is a material that produces a high, linear mu level for high initial bite and consistent grab through a wide heat range. These low dust brake pads are equipped with noise abutment shims that control NVH issues. Unlike carbon pads or ceramic pads, our high performance pad material is also environmentally complaint to the upcoming California and Washington legislation (pending in other states) that requires the elimination of copper and other harmful pollutant byproducts in brake dust that eventually make their way into our water systems.

STILLEN has also worked hard to ensure a wide range of pads are available for this caliper.  All kits come with the standard brake pad optimized for low dust, NVH and performance driving however race pads are available upon request.

  • Performance street brake pads included (various pad compounds available)
  • Standard pads feature low dust composition with performance street driving in mind
  • Optional brake pads for enthusiasts looking to take their driving to the next level

Stainless Steel Brake Lines


This is an often overlooked component in performance braking. Brake lines used in the AP Racing Radi-CAL kits are built using extruded PTFE hose that is wrapped in corrosion and fire resistant stainless steel braided hose and then covered with a clear plastic coat for additional protection. Each brake line design goes through rigorous testing and must pass the whip test, where the line is whipped through thousands of cycles, before being approved for production.

The result is the most efficient delivery of fluid pressure to the brake caliper, bringing a solid feel to the brake pedal sure to inspire confidence at every brake zone. By reducing the factory rubber lines ability to swell or expand means a quicker response, firmer more consistent pedal feel that allows for great brake modulation.


All AP Racing by STILLEN brake lines are provided by Goodridge.  Goodridge is the leading brake line supplier in the industry and one of the only companies to achieve DOT compliance.


Who is AP Racing

For over 50 years AP Racing has been recognized as the leader in motorsport friction technology.  In 2016 alone AP Racing supplied brakes and/or clutches to over 30 champions across multiple disciplines of motorsport.  AP Racing is the primary brake component supplier to NASCAR, WRC and other major forms of motorsport around the world as well as the spec clutch supplier for Formula One while also supplying half the field with racing brake components.  To date AP Racing has won over 700 Formula one Grands Prix.

There is no other friction manufacturer that has the experience, or track record to match AP Racing.



In 1990 STILLEN company founder Steve Millen was testing at Mosport International Motorsport Park only one day after joining his team in a successful campaign at the 24 hours of Le Mans.  The purpose of the test was to develop a new braking system for the world famous IMSA 300ZX twin turbo race car which Steve would later take to victories at Daytona, Le Mans, Sebring and multiple world championships.  During the test Steve discussed his passion for tuning high performance roads cars and that he was looking for a solution to improve the brakes.  He was making the cars more powerful, handle better and as an experienced racer knew that this improvement in speed needed to be matched with an improvement in braking.  Since this initial conversation in 1990 STILLEN has continued developing high performance big brake kits for all makes and models of cars, trucks and SUVs.

Best Brake Upgrades 101: Rotors & Pads

By Richard Fong

Best Brake System 101: Rotors Pads stillen_u_banner_v1

There’s no point in being able to go if you can’t stop. While an engine provides locomotion to a car, the braking system is what brings your vehicle to a stop. The average automotive brake system is hydraulic and typically consists of the pedal assembly, vacuum booster, master cylinder, hydraulic lines, calipers, rotors and pads – and of course, on nearly all modern vehicles, an Anti-Lock Brake System module and pressure tank.


The braking system is not only a CRITICAL performance element, it’s also imperative for safety and the safe operation of a vehicle. That’s why STILLEN offers Brake Upgrades for a variety of vehicles, from big brake kits to performance replacement parts.

OE Replacement Brake Discs and Pads

As is often the case, many standard vehicle components are designed as a compromise – balancing quality versus price, versus Noise Vibration Harshness (NVH) concerns – the end result being a pad that isn’t well suited for trackday performance. This means that in all likelihood, your OEM brake pads probably don’t do very well in ‘high performance’ conditions.


Brake Pad Construction

Brake pads are composed of a backing plate and a friction compound that creates friction when placed in contact with the brake rotors, enabling a vehicle to stop. The way your brakes work is kind of like how the brakes of a bicycle work. Pushing the pedal causes the calipers to squeeze the pads against the spinning wheel hub/rotor, slowing its rotation, much like your bike’s rubber brake pads grab the edge of the wheel of your bicycle to bring you to a stop.


Before moving on, we need to remind you that a high performance pad is going to be noisier and dustier – those are the facts. If you’re wanting a pad that offers extreme performance without dust or noise, know that it just doesn’t exist, at any price. Sorry, but if you want performance from your brake system, you’re going to have to deal with brake dust.

Your Stock Brakes Probably Aren’t As Good As You Think

With the exception of premium performance-oriented vehicles that include performance brake components from the factory, most vehicles are equipped with braking systems that are best described as “Adequate”. If you take the average stock vehicle to the track or even on a spirited drive, and you’ll quickly learn its shortcomings. The sad thing is, many car’s brake systems can start to get overwhelmed after just a few aggressive corners.

Stillen Brake Pads Metal Matrix


What happens if my brakes can’t deal with the demands of performance driving?

To understand the importance of a good brake compound and just how big a role it plays, let’s do a quick thought exercise.

Imagine accelerating down a stretch of canyon road, you’re accelerating hard on the straights, and then braking just before engaging a turn, or series of switchback curves. The first time you hit the brake pedal, everything works as it should, shaving speed and allowing you to hit the apex of the turn with ease. However, a few corners (or hotlaps) later, suddenly, the pedal gets all mushy, and instead of slowing and allowing you to adjust your line, the car just plows ahead, because the brakes don’t have any bite. You desperately stomp on the brakes in hopes you can still adjust your speed, correct and make the turn– but your efforts are in vain. Before you realize it, you’re way past the apex and are either off line or off track, or even worse, into the guardrail or Armco barriers. This is the biggest problem of an insufficient brake system rearing its ugly head. This is the beast known as Brake Fade.

Brake Fade Graphic

What is Brake Fade, exactly?

Brake fade is the enemy of safe and reliable braking and it’s not your friend. Brake fade occurs when the friction efficiency and/or heat capacity of the brake pads or rotors is exceeded, and as a result, the ability of the brake system to slow or stop the vehicle becomes compromised. Whether it’s on a twisty mountain pass or on a racetrack, when you discover the limits of your vehicle’s braking performance firsthand, it leaves much to be desired in terms of performance. Fortunately, the aftermarket could be the answer to your problems, because chances are, someone offers a solution for your application. There are a few ways to mitigate brake fade.

Best Brake System 101: Rotors Pads HawkCleaned

Bring Back the Friction

One of the best performance mods for your car and most straight-forward upgrades you can make is a set of Brake Pads. Brake pads, like rotors and fluid, are wear items that can be replaced with upgraded versions of replacement parts. Most factory brake pads are designed to be as quiet as possible with as little dust as possible. These characteristics require compromises that take away from the performance of your brake pads.

Can You Put Race Pads On And Drive On The Street?

The demands of racing versus stop and go traffic are very different, OEM street pads don’t perform their best under race conditions, and outright RACE brake pads won’t perform well if used for street driving conditions. Logically, one might think, pads designed for “RACE” performance must be overkill for the needs of street driving, right? Frankly, no.

Way back in the good ol’ days of 2002, Popular Mechanics compared Jeff Gordon’s #24 NASCAR Monte Carlo against a fresh-off-the-line FWD Monte Carlo SS to get an idea how the race car performed relative to its streetcar namesake. One would think that the race car’s massive brakes would make it the obvious winner, right? Both cars were tested as is standard practice for a head-to-head – cold, like your car is when you first start driving after being parked for a while.  Can you guess what happened?
(ref: Popular Mechanics, November 2002, A Tale of Two Chevys)

Well, the street car Monte Carlo outperformed the #24 NASCAR racecar’s gargantuan race brakes and the street car stopped much shorter – the polar opposite of what ‘common sense’ would suggest. That generation of Monte Carlo wasn’t exactly a performer either, making its victory over the racecar that much more shocking.

Why? Because of the temperature the brakes were designed to work at. The NASCAR race car’s brakes are designed to be used HARD, over and over again when hot, braking from speeds well over 100… to get that kind of performance when the brakes are that hot, the engineers had to sacrifice performance when cold.


This chart from HAWK Performance offers a great visual for the temperature ranges that brake pads are designed to operate in. As you can see, pads that perform well cold do not perform well past 700*f or so, and conversely, pads that perform well when hot don’t start to grab until 200-300* f.

The Right Pad for the Right Purpose

Each pad type and compound is optimized depending on your vehicle’s intended purpose. There are a plethora of High Performance OE Replacement Brake pads available from STILLEN, DBA Brakes and Hawk Performance to name a few, and these pads are offered in a variety of friction compounds ranging from organic and ceramic to semi-metallic to suit a variety of different driving demands.

The other thing to note here is that sometimes, a car is factory-equipped with high performance brake pads, but the generic replacement available from the local auto parts store might perform terribly by contrast. So, despite every part of the system working properly, underperforming brake pads mean it suddenly takes much more distance to stop than it used to- and if you’re used to the car’s original stopping distance, this increased in stopping distance could cause an accident, so be sure that the replacement pads you’re installing are able to handle the way you plan to use them, before you buy.
Pro-Tip: If the brake pad has “Quiet” in the name, it’s a safe bet that pad won’t do well on a track.

Let’s take a look at some of the pros and cons of different brake pad compounds so you can better determine what might be best for your needs.

Picking The Right Brake Pad Compound for the Way YOU Drive

Brake Pads Graphic

Organic (Common OEM Material)

Pros: Less aggressive rotor wear, decent initial bite, manageable brake dust generation

Cons: Mediocre braking performance, tends to wear quickly, prone to brake fade

Organic pads offer good initial bite (initiation of friction and slowing of the vehicle) and modulation for daily driven vehicles, but generally suffer rapid wear and fade when subjected to aggressive driving.

Best Brake System 101: Rotors Pads HawkFrontPads

Ceramic (Common OEM Material, Aftermarket Upgrade)

Pros: Moderate rotor wear, good wear characteristics, less prone to brake fade, moderate dust production, ideal for rotors lacking slots or cross drilling, the middle ground between organic and semi-metallic pads

Cons: Higher cost, limited compound options, less aggressive friction traits, not ideal for the track

Ceramic pads cost more but take the best traits of organic pads and can add longevity as well as reduced brake dust production. However, these pads suffer accelerated wear under heavy loads and are not ideal for track or heavy-duty braking situations.

Mintex Brake Pads NASCAR

Semi-metallic (Common Aftermarket Material, Aftermarket Upgrade)

Pros: Broad selection of available compounds, improved resistance to fade, improved heat rejection when used on slotted or cross-drilled rotors, permits tailoring of braking performance traits depending on driving conditions by changing compounds

Cons: Potentially aggressive rotor wear, excessive dust, noise (brake squeal)

Semi-metallic pads tend to resist fade better and offer superior heat capacity and dissipation compared to organic or ceramic pads. They are offered in a variety of compositions enabling the end user to choose the braking characteristics desired of their vehicle. When choosing a semi-metallic pad, aggressive initial bite could be desirable in the case of a vehicle driven hard for short intervals.

The counterpoint is that this pad could eventually suffer from fade with prolonged aggressive driving. By comparison, a semi-metallic pad formulated for endurance offers increased heat capacity for longer driving intervals, but will likely lack initial bite when cold and suffer reduced braking performance until brought up to optimal operating temperatures. This is not ideal for short driving intervals or street driving since the ideal temperatures are much higher and might not be reached under these conditions.

In other words, semi metallic endurance RACING brake pads will be unable to perform for “street use” because they will not be at their intended operating temperature a vast majority of the time – meaning it’s not smart to drive from your house to the race track on your ‘trackday’ brake pads. It won’t be fun when you roll right past that first stop sign or can’t slow down as you get off the freeway because the RACE COMPOUND brake pads are too cold.

As the only USA Distributor of AP Racing products, we’ve got a huge selection of replacement and performance replacement brake pads for a variety of applications here at STILLEN in stock and or readily available to suit your needs from the most trusted manufacturers in performance brakes. Whether it’s a daily driver or a track rat, we likely have a solution available – talk to our team today to see what we have for your application.

STILLEN J-Hook 2pc Rotors Set of 2

Release the Heat

Another common brake system improvement involves upgrading the surface that the brake pads apply friction to, the Brake Rotors. Brake rotors are not only a friction surface, they also serve another important function – they are also heat sinks. This means that they must draw away and dissipate the heat produced by the friction of the pads efficiently to stave off brake fade and ensure consistent braking performance. Factory brake rotors are typically made of iron, because it’s inexpensive and offers longevity and enough heat capacity for the average everyday driver. Trick is, the way the “average driver” drives a car is nothing like the ‘Spirited Drives’ you and I enjoy.

Not all iron is created equal, and STILLEN rotors are produced using an alloy that offers more efficient thermal transfer characteristics and features bigger, better flowing cooling vanes to create a rotor with superior cooling characteristics, but these added features and the use of more expensive materials does increase cost. As a result of cost-saving concerns, typical factory rotors do not benefit from the design elements and use less expensive alloys that lack the heat dissipation characteristics found in STILLEN brake rotors, making a set of Performance Replacement Brake Rotors an especially effective upgrade.

STILLEN J-Hook 2pc Rotors Detail pair

Fighting Fade With Improved Brake Rotors

Aftermarket brake rotors, like those offered by STILLEN, AP Racing and DBA (for example) feature a variety of benefits, thanks to engineering innovations like improved vane design (in the case of vented rotors) as well as cross drilling, slotting and other surface treatments. Many people mistakenly believe that rotors suck air in through the vanes, but it’s actually the opposite. Think about what happens when you have a dirt bike’s rear tire caked in mud, and then blip the throttle. The wheel spins, flinging mud OUTWARDS off the wheel and away. Same idea applies to how air flows through your rotor. Brake rotors draw in air from the center of the hub and the spinning of the rotor flings the hot brake gases outwards through the vanes, cooling the rotor.


It works like this, when your brake rotor turns, it acts as an air pump, drawing in cooler air at the hub and forces that air out, carrying away hot brake gases out through the vents, so it’s worth saying that a rotor’s internal design can play a huge role in its effectiveness.

Best Brake System 101: Rotors Pads IMG_5988 Best Brake System 101: Rotors Pads IMG_5959

In the search for improved methods of heat dissipation, some manufacturers of vented rotors have implemented proprietary vane designs to facilitate improved airflow for better cooling of the rotors.


As an added measure of cooling, some have turned to cross-drilling the rotor surface, which provides additional pathways for hot brake gases to escape, thereby enhancing cooling.


Another brake rotor type is the slotted rotor. Most commonly, simple slots are cut into the rotor surface help to optimize the friction surface area while helping to release the gasses that build up between the friction material of the pad and the rotor surface. However, the downside of this rotor type is accelerated wear on the pads, meaning slotted rotors shorten the typical service life of the pads used with them.


Some enthusiasts choose to go with both of these features and opt for Drilled & Slotted rotors, and still others go for the polar opposite and get “blank” rotors for an OEM appearance.

Step Up and Stop Better

Best Brake System 101: Rotors Pads IMG_8172

With a better grasp of the basics of brake upgrades and the first steps toward better braking for both performance and safety, contact us to order your upgrade today! Do you have more questions about what would be right for your application? Reach out to us at 866-250-5542, at sales@stillen.com or by live chat on our website stillen.com to help you select the product that best suits your needs.

In our next installment of STILLEN University, we’re going to explore brake system upgrades in greater detail and dig into Torque Friction Surface Area in Stillen U, Brakes 301! Check back with us soon!

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You might be wondering… When it’s time to replace your brake rotors, should you upgrade your brake rotors or just replace them with identical OEM rotors? One tip the STILLEN brake experts offer: consider how you use your car.

Is it a daily driver used for commuting and errands? Are you an enthusiast who lives for the open road and canyon carving? Or maybe you participate in autocross or track days.

Regardless, there are many choices in rotors, and one way to shop for replacement brake rotors, as well as brake pads and brake fluid is with a Good- Better – Best approach.

For more info about this approach, check out this how-to video from STILLEN expert Mark.


Brake Rotor Upgrade Level: GOOD

Drivers seeking a good rotor that offers a performance and durability upgrade from OEM rotors should consider upgrading to STILLEN OEM replacement brake rotors.  They are well suited for aggressive driving and the occasional track day.

Features include straight cut vanes, zinc coating, chamfered slots and precision ground friction surfaces.  Multiple machining options are available, from slotted to cross drilled to the popular hook slot hybrid finish.

Available for virtually any passenger vehicle on the road today, STILLEN sport rotors are proudly Made in USA.

Brake Rotor Upgrade Level: BETTER

For hard core enthusiasts and track day fans concerned with high temperature heat management, a better option might be the DBA 4000 series brake rotors. These discs offer more sophisticated metallurgy for longer life.

They also feature DBA Kangaroo Paw vane technology. These vanes are multi-directional, meaning they draw cooling air in from any direction.

This improves heat dissipation and also permits the rotors to be mounted on both driver and passenger side hubs. Another stylish touch is the available gold rotor vanes and hats.

Brake Rotor Upgrade Level:  BEST

The ultimate brake rotor upgrade could be the DBA 5000 series.  Suitable for frequent track use, these rotors offer the Kangaroo paw vane technology and improved metallurgy of the 4000 series, but add a two piece design.

The rotor hat is a separate assembly that is bolted to the brake rotor. This helps isolate the wheel hub bearings from excess heat, reduces brake vibration caused by rotor warping under heavy use, and offers weight savings as well.

One indicator the DBA 5000 series are meant for serious drivers is the brake temperature paint applied to the rotor edges. These indicators help drivers ascertain the temperature range their brake system is operating in.

This in turn helps determine proper brake pad and brake fluid selection for track use.

Brake Pad Replacement and Upgrades

It’s always advisable to replace brake pads when mounting new rotors. STILLEN Metal Matrix brake pads offer a nice blend of bite and power along with reduced dust and noise. This makes them ideal for street and occasional track use.

Other brake pads might be better suited for full-on track use, such as the Hawk HPS 5.0s or Ferodo DS2500 HP.

Brake Fluid Replacement

When you’re considering brake system upgrades, it’s essential to include brake fluid replacement in the thought process.

One popular opinion is that it’s best to upgrade to racing brake fluid.

As STILLEN brake expert and all-around good guy Mark explains, this is a common misconception.

While your OEM brake fluid does have a limited heat capacity, so does your OEM brake system. Upgrading your rotors and pads does give you a higher threshold, but your calipers still have a limit.

If you upgrade your brake fluid past what the calipers can handle, you could exceed your brake systems operating envelope without knowing it. Should it occur, brake fluid boiling is an indicator that your brake system is overheating.

Going with a little bit of an upgrade is fine, but you don’t need to go with a full-on race brake fluid.

While shooting the how to video for brake upgrades, Mark installed the DBA 4000 series rotors and STILLEN Metal Matrix brake pads on his Subaru BRZ and had the following to report:

“After we finished the install on the brakes, we moved onto the bed-in procedure then onto our test drive and you could really feel the difference. Our stopping distances were much shorter, our initial bite was much better and brake fade was much less apparent as the brakes heated up so this is an awesome upgrade for the BRZ or for any vehicle. You can really improve your driving experience.”

Questions About Brake Rotors?

Our brake experts are standing by and will stop at nothing to help you in quest for better braking. Take a brake from whatever you’re doing and call them at 866-250-5542!

It’s that time of year again.. thousands are burning up the 30+ miles worth of carpeted aisles at the infamous SEMA Show in Las Vegas!  The STILLEN Team is no exception, with a big booth introducing the world to the new AP Racing Radi-CAL line of calipers used in the STILLEN-engineered Big Brake Kits.

AP Racing Radi-CAL Brake Caliper Launch at SEMA with STILLEN

These new Radi-CAL road calipers get there heritage from the racing Radi-CAL high performance calipers launched in motorsports in 2007, which have been dominating the likes of F1, F3, NASCAR and countless others.  This new caliper design features a 2-piece aluminum body with H-structure, and a non-symmetrical design developed to have a large reduction in mass yet improved resistance to braking torque.  Another benefit is increased caliper cooling surface without decreasing structural rigidity.

AP Racing Radi-Cal By STILLEN with Black Caliper

STILLEN has developed applications for many popular setups, which are listed below, and have plans to continue to grow the line.

We will be releasing much more information as we return from SEMA, and the response has already been overwhelming at it’s introduction!

When nothing but the best will do, serious customers look to AP Racing and STILLEN.

STILLEN / AP Racing Booth at SEMA 2013

STILLEN / AP Racing Booth at SEMA 2013

Radi-CAL in red


Radi-CAL in black

GTR Brakes

STILLEN Announces CCM-X – The next generation of Carbon-Ceramic Matrix Brakes for the Nissan R35 GT-R

The STILLEN R&D team continues to develop industry-leading performance products with long-standing technical partner AP Racing. Their hard work has resulted in the release of the next generation in Carbon-Ceramic Matrix (CCM-X) brakes for the Nissan GTR. This kit utilizes a new High Thermal Capacity (HTC) process which helps pull the heat from the CCM disc surface deeper into the 3D core to allow the discs to operate cooler through more efficient use of internal venting and air flow.

We have also homologated a new Pagid RSX1 pad material designed specifically for our new CCM-X discs for easier bedding and higher performance, these pads are ideal for use on the street and for track days.

The CCM-X disc assembly hardware has now been updated to include anti-rattle springs that still allow the full benefit of a floating disc, yet eliminates the “noise” associated with this style of disc.

During extreme performance testing at Auto Club Raceway in Fontana, CA, performing back-to-back repetitive testing runs pushing the limits of brake temperatures, the new combination of HTC CCM-X discs and Pagid RSX1 pad material reduced disc temperatures from an average of 1488F to 1346F, that’s 142 degrees cooler than the previous generation CCM. These real-world tests confirmed the results of our brake dyno testing at AP Racings lab in Coventry, England.

Once found only on the world’s most expensive supercars, Carbon-Ceramic Matrix (CCM) brakes have been developed for the first specifically-tuned aftermarket application – the Nissan R35 GT-R. These 400mm disc assemblies are larger than the standard OE iron discs, yet reduce weight by nearly half. This is rotating and unsprung weight, leading to improvements in all performance categories: acceleration, handling and braking.

After three decades of using carbon-carbon brakes on racing vehicles (even longer on fighter jets), AP Racing CCM discs are the next technological platform. Advancements in materials, process technologies and nanoparticle technology make it possible to use a special carbon fiber precursor along with new, patented process techniques. The unidirectional precursor is needled into a 3-Dimensional, continuous carbon fiber preform. This differs from lower cost technologies that use loose, chopped strand fibers and thin woven face plies bonded on as a friction surface. A true 3D matrix is stronger, more robust and provides longer life than the more brittle alternative. As a comparison, think quality hardwood versus particle board or MDF with a veneer.

Converting the 3D preform to carbon-carbon is done under high heat and pressure via methane cracking during a special carbon vapor infiltration (CVI) process. After initial machine work, a final conversion process results in a full matrix carbon-silicon carbide (CSiC). We call it Carbon-Ceramic Matrix, or CCM for short. The discs are then sent through the final machining, grinding, and balancing. Of course, the CCM discs are now so hard that only special diamond tooling can be used!

Who uses these ultimate CCM discs? The most up-to-date version is found on the Koenigsegg CCX and McLaren MP4-12C. And now – STILLEN and AP Racing have optimized a specific set for your R35 GT-R and its factory brake calipers.

The STILLEN-AP Racing CCM-X brake upgrade kit includes:

  • Front & Rear CCM-X brake disc/hat assemblies
  • Front & Rear Pagid RSX1 street & track use brake pads
  • Caliper spacers
  • Active brake cooling package required by Track Users (Not Shown – Sold separately and can also be used with Iron Rotors)

Note: Due to the dramatic reduction in overall mass, brake temperatures will run higher than the O.E. iron disc system given the same usage. STILLEN strongly recommends using AP Racing PRF brake fluid, one of the best high temperature fluids available. PRF is used in the most demanding Motorsports applications around the world.

Photos from Testing at Auto Club Speedway in Fontana, CA:

GT-R doing a fly-by past STILLEN R&D Testing Equipment

GT-R doing a fly-by past STILLEN R&D Testing Equipment

Under the extreme conditions that the Carbon Ceramic kits are tested, rotors can glow bright orange

Under the extreme conditions that the Carbon Ceramic kits are tested, rotors can glow bright orange

STILLEN R&D Logging Equipment

STILLEN R&D Logging Equipment

To get the best results, brake changes from old CCM to the new CCM-X were done at the track so outside conditions wouldn't be a big factor in test results

To get the best results, brake changes from old CCM to the new CCM-X were done at the track so outside conditions wouldn’t be a big factor in test results

CCM Kit Under stock 2012 R35 GT-R wheels

CCM Kit Under stock 2012 R35 GT-R wheels

STILLEN CEO Steve Millen under hard braking past a waypoint cone

STILLEN CEO Steve Millen under hard braking past a waypoint cone

Steve Millen, Kyle Millen and other members of the STILLEN R&D team discussing the difference in brake performance

Steve Millen, Kyle Millen and other members of the STILLEN R&D team discussing the difference in brake performance

One of the more popular products we make for the Nissan GT-R has been the polyurethane Protective Skid Plate, and with the changes to the new 2012 GT-R’s front lip, this required a new skid plate to be designed. Proud to announce we are in final development of the new version for the new model!

Here’s a sneak peek inside the STILLEN modeling shop located in Costa Mesa, CA, and shows the final piece test fitted on the car before we sent it into mold preparation.  The final production part will be black urethane, sprayed with a black matte paint, and can also easily be painted to match any specific color if desired.

The skid plate is designed to protect the extremely expensive front fascia from scrapes and light bumps. It follows the specific contours of the car, and installs in just minutes with everything needed supplied.

We are in full swing with the 2012 Nissan GT-R, and are also nearly finished with the Front Lip Spoiler, as well as the Aerodynamic Side Skirts which are also available for the 2009-2011 GT-R.  Look for more information soon.

We’ve also been doing product fitment on other STILLEN items, such as our Cat-Back Exhaust System, Secondary Cat-Delete Y-Pipes, Stainless Steel Brake Lines, AP Racing rotor upgrades and much more!

Last month we brought you the information on the new high end Goodridge Phantom Gstop Brakelines, and as these are arriving soon, we wanted to get the word out, and get these in the hands of our customers, so we’re giving away 2 sets for free!

Simply head over to the STILLEN Facebook page, give us a ‘Like’ and you’ll have access to the entry form on the Sweepstakes tab, just pop in your information and you’ll be entered to win.  We’ll be picking a winner on April 15th, and again on April 30th!

The Phantom Brakelines are new from Goodridge, and are designed to replace the factory rubber brake lines on your car, improving safety, reducing stopping distances and deliver a much better brake pedal feel, just like the popular Goodridge Gstop Brakeline kits.  The Phantom series upgrades the hardware and fittings to stainless steel, features a black coating on the stainless steel lines, a beautiful upgrade, and we couldn’t encourage our customers more to consider upgrading your brake lines if you haven’t already, it’s an inexpensive upgrade that has huge benefits.

Good luck!  You can read the full giveaway rules here.

Goodridge has released information on their new limited edition Phantom Gstop Brakeline kits available for popular selected applications. For the ultimate brake line upgrade, look no further!

Upgraded stainless steel brake lines are one of the easiest modifications to make and get tangible results from.  Installing Goodridge G-Stop SS lines will dramatically improve brake pedal feel, eliminate the soft spongy feeling, and improve braking performance and reducing stopping distances.

The Phantom G-Stop kits take that performance and kick it up a notch, utilizing stainless hose ends, banjos and bolts, as well as feature black poly-coating to the stainless steel hoses.  Even the brackets and hardware are protective coated, creating a superior appearance, and ensuring durability.

All of the benefits of the best brakeline manufacturer, Goodridge, with upgraded hardware and coatings makes this a great modification for any enthusiast!


Initial Phantom Brakeline Applications Include:

  • 2010-2011 Chevrolet Camaro SS
  • 1997-2004 Chevrolet Corvette (Including Z06)
  • 2005-2011 Chevrolet Corvette C6 (Except Z06)
  • 2006-2011 Chevrolet Corvette Z06
  • 2003-2007 Infiniti G35 Coupe (Including Brembo)
  • 2003-2006 Infiniti G35 Sedan (Including Brembo – Excluding AWD)
  • 2003-2007 Nissan 350Z (Including Brembo)
  • 2009-2011 Nissan GT-R R35
  • 1997-2004 Porsche 911/996 (Including Turbo)
  • 2005-2008 Porsche 911/997 C2, C4, C4S
  • 1997-2004 Porsche Boxster/986 (All Models)
  • 2003-2006 Subaru Outback
  • 2002-2007 Subaru Impreza Wagon, WRX & STi
  • 2008-2011 Subaru Impreza WRX (Except STi)
  • 2006-2011 BMW 128i (E82/88)
  • 2006-2011 BMW 135i (E82/88)
  • 2007-2011 BMW 328i exc. Xi (E90/91/92/93)
  • 2006-2006 BMW 330i exc. Xi (E90/91/92/93)
  • 2007-2011 BMW 335i exc. Xi (E90/91/92/93)
  • 2005-2011 Ford Mustang GT (Including 5.0)
  • 2007-2011 Shelby GT500
  • 2005-2011 Ford Mustang V6 (with ABS)
  • Various 1998-2007 Mercedes C-Class / E-Class / SLK

News Release
For Immediate Release

FOR 2000-2010 GM 2500/3500 TRUCKS

Costa Mesa, Calif.– STILLEN announces the availability of a new front and rear big brake system for the 2000-2010 Chevrolet Silverado 2500/3500 and GMC Sierra 2500/3500 (including Dual Rear Wheel models). This rugged, state-of-the-art brake upgrade is based on AP Racing brake technology, the number one choice for a wide range of professional race teams that compete at the highest levels (i.e. NASCAR, FORMULA 1).

Available from the STILLEN brake product division, these GM Truck brake upgrades are compatible with OE ABS, traction control and stability systems as well as the original master cylinder to provide the ultimate in towing and big load capacity.

The front Big Brake System (AP2320) features AP Racing’s new, oversized 6-piston Heavy Duty caliper (CP8510) matched with the largest available aftermarket (16.1” diameter) 2-piece floating cross-drilled and slotted rotors. Slotted-only rotors are a no-cost option. This STILLEN brake system also includes high-performance Ferodo DS2500 brake pads along with Goodridge stainless steel brake lines, brackets and all necessary mounting hardware for immediate bolt-on.

For the matching and balanced rear Big Brake system (AP6950), STILLEN specified a special version of AP Racing’s Heavy Duty 4-piston caliper (CP5328) clamping on 15″ diameter 2-piece cross-drilled and slotted rotors, also available in slotted-only. The rear upgrade also includes Ferodo DS2500 brake pads and all necessary hardware.

This powerful brake system requires 20” or larger wheels with adequate spoke clearance. To ensure proper fitment, customers should visit www.stillen.com to download an easy-to-use brake profile template to check wheel fitment for both the front and rear brake kits before ordering. When ordering custom wheels, consult with STILLEN in advance to ensure compatibility.

To learn more about AP Racing Big Brake upgrade kits for the 2000-2010 Chevrolet Silverado 2500/3500 and GMC Sierra 2500/3500 and other pickup trucks, visit www.stillen.com, e-mail pr@stillen.com , or call (866) 250-5542.

# # #

Developed by enthusiasts for enthusiasts, STILLEN is a manufacturer and distributor of premium high performance products for late model import and domestic vehicles. Founded in 1986 by renowned professional driver and race car builder Steve Millen, STILLEN incorporates cutting-edge race proven technology and advanced aerodynamic designs into the company’s proprietary performance and appearance product lines. Millen is known worldwide for achieving the greatest number of wins in IMSA GT history during the course of an impressive 30-year racing career. Family owned and operated, STILLEN branded products include exhaust systems and components, superchargers, fuel systems and components, brake kits and components and urethane body styling products. In addition, STILLEN is an online reseller of many high performance products for late model cars and trucks, import and domestic, and creator of unique, one-of-a-kind performance project vehicles. For more information, visit www.STILLEN.com.

After months of testing and road racing, STILLEN is proud to announce the availability of the first Active Brake Cooling Package made specifically for the R35 Nissan GT-R.  This kit has been shown to reduce rotor temperature on the AP Racing Carbon Ceramic Brake Upgrade by over 200 degrees F, and is also extremely effective for those running standard OEM Iron, or the AP Racing Curved Vane Rotor Upgrades.

GT-R Front Active Brake Cooling System

The front cooling kit consists of weather resistant electric fans, polyurethane air diversion splitter, all appropriate mounting brackets, and includes a wiring kit as well as a switch.

GT-R Rear Brake Cooling System

The rear cooling kit utilizes polyurethane air scoops which work in conjunction with the factory NACA ducts in the belly pan to route air to the braking system, and also features polyurethane air funnels, accordian tube and all necessary mounting bracketry.

For detailed information on the design and testing of the STILLEN Active Brake Cooling Package, please visit the STILLEN website for much more information.