1. Which brake pads can be used with carbon ceramic discs.
Currently, the best option brake pads for carbon ceramic discs are organic compounds made, which are similar to be used with traditional iron brake discs but different. These are pads are more low-metal or semi-metal pads. Our carbon ceramic brake discs can be used with Pagid Racing RSC series pads, and Pagid Racing RSL29 pads. But these are not available for every shapes now. We have developed our own low-metal pads, covering any shapes of pads. These brake pad compound are speciality developed for carbon ceramic brakes.
2. What’s the advantages of CMCMAT’s carbon ceramic brakes?
Light weight, saving as much as 70% mass versus steel
Stable CoF, Coefficient of Friction
No heat fading
Shorter braking distance
No thermal shock nor expansion
Longer life-span than previous gen CCBs
3D needle- punched carbon fiber structure
Higher intensity, retain structural integrity up to 1800⁰ C
3. How do you make a 3D continuous Carbon Ceramic disc?
We made the carbon ceramic discs in 3 steps. First, the carbon fiber preform, 3D needle-punched directly with continuous carbon fibers, which ensure the strength of the discs. Second, the carbon carbon material, it is a carbon carbon ring with density 1.45 g/cm3. We use CVD (chemical vapor deposition) technology to make the carbon fiber preform become carbon carbon. Third, carbon ceramic disc. After machining the carbon carbon ring to the required application, we use RMI (reactive melting infiltration ) to make the carbon carbon to carbon ceramic.
4. What are ‘next-generation’ Carbon Ceramic brakes?
For nearly 40 years now, since the 1970s, classic traditional carbon ceramic discs havebeen made from discontinuous (chopped) carbon fibers with a mold, exactly as in the Youtube/How It is Made https://www.youtube.com/watch?v=3D9ayaGQiV4 .
But CMCMAT is making the next-generation carbon ceramic disc from continuous carbon fibers with 3D needle-punched technology. With high grade (Japanese T700 Torayca) continuous carbon fibers and 3D needle-punched technology, our discs have a lot of benefits compared with traditional carbon ceramic discs.
1). Stronger. Unlikely to crack with a 3D continuous carbon fibers structure in the discs, disintegration occurring as temperatures approach 1800C, a temperature unlikely to be encountered outside the most extreme motorsports applications.
2) Longer life span. The whole body of the disc are C/CSi material. Theoretically, it can be used as its whole life.
3). Higher heat conductivity. Faster heat releasing to ensure excellent brake performance.
4). Can be used both on track and street.
5. What is the difference between carbon carbon brakes and carbon ceramic brakes.
The matrix of carbon carbon material is carbon only. Carbon carbon brakes are always used in Formula 1 or DTM. The brake performance goes higher when the temperature goes higher. It is not so good for everyday driving. And it is even lighter weight than carbon ceramic. That’s another reason why it is chosen for Formula 1. But it is softer, and easy to be worn out. Thus he team will have to replace the discs after every race. Carbon carbon discs always work with carbon carbon pads only, like the aircraft carbon brake pairs.
The main ingredient of carbon ceramic discs are C (carbon) and CSi (ceramic). The friction of carbon ceramic discs are relatively stable, will not change much as the temperature changes. The stiffness of carbon ceramic is very high, that’s why we need to use diamond knifes to cut it when we do the balancing. And the life-span of the carbon ceramic disc is very long, almost equal to a vehicle’s life. Low-metal or semi-metal pads are proven to be the best option pads for carbon ceramic discs. But these pads are special formulated to carbon ceramic brake discs, not every pads are working effectively. There is a saying that F1 will use carbon ceramic brakes in the future. But carbon ceramic brake discs have been installed on aircraft for many years.
6. Why brake bedding is essential for carbon ceramic brakes?
Brake bedding is also called brake-in or conditioning. During the process of the bedded-in, the brake pads compound will be transferred on the friction surface of the carbon ceramic brake discs. The process mainly contains heating procedure and cooling procedure. After the process finished properly, the discs friction surface will be covered with brake pad compound homogeneously. If not, it may cause NVH issues(Noise, Vibration, Harshness). CMCMAT has developed a procedure of bedding carbon ceramic brake discs.
7. How do I bed-in my rotor and pads?
Following the pad and rotor bedding procedure should ensure that an adequate transfer of pad.
1). Initial bed-in
Speed: gentle stops from 80km/h to 30km/h
Pedal strength: ≤50%
Repetition: 20 times
Effect : rotors and pads fit
2). Heavy bed-in
Speed: heavy stops from 150km/h to 120km/h
Pedal strength: 30%→50%→80%
Repetition: 10 times
Effect: friction layer formed between rotors and pads.
3). Cool bed-in
Speed: stop from 80km/h to 30km/h
Pedal strength: ≤50%
Repetition: 20 times
When you finish all above steps, surface of rotors will be shining. Please repeat above steps if the rotors have no good effect due to the car model and road situation difference.
8. Which vehicle applications has CMCMAT developed?
We have developed carbon ceramic brake discs and special pads for mainly performance cars in the market. The following brands are already covered by us: BMW (M Performance or M), Mercedes AMG series, Audi RS series and S series, Porsche, Ferrari, Lamborghini etc. Please ask us for the application list. And we are keeping developing applications for more vehicles. Customization or OEM are available. Please let us know your project, we are able to provide you a suitable solution.
9. Can we keep our stock calipers?
We can tell after we evaluated your project. We offer play and plug in solutions for many performance cars. Customers just need to replace the original steel brake discs and original brake pads. We can supply the OE size carbon ceramic brake discs and OE shape special brake pads for you.
10. How do we measure the pad or rotor end of life?
Most CMCMAT 3D Carbon Ceramic rotors will exceed the life of the vehicle, and still be good when the ownership transfers. Potential new clients may worry if they are about to receive worn-out rotors. Our rotors are guaranteed to be delivered with a 2mm surface tolerance, and a default pre-bedded process that should ensure a headache free mating of the new pads with the brand-new rotor discs. Methods to determine that a 3d Carbon rotor is nearing end of life is to check the thickness of the rotors. When the rotors were worn to the suggested thickness, we suggest to replace the rotors.
Although the rotors should last hundreds of thousands of Kms, this is not the case with the pads. The pads are the softer of these two materials, with the right composition that ensure maximal braking characteristics, and wear against a ceramic surface that does not change. It is recommended to service and inspect the pads especially after repeat track sessions, annually or bi-annually in order to ensure that the pad surface is optimal. In the extremely rare case of a minor debris lodging on the pad, a prompt inspection is recommended to avoid that debris wearing cutting the rotor surface. As the pad nears its end of life, the owner has the option of ordering one of many CCB compatible pads. Alternatively, CMCMAT can procure a replacement according to the pad’s industrial design code and dimensions.
11. What if I develop NVH (Noise, Vibration, Harshness)?
Bedded in CMCMAT Carbon rotors are unlikely to develop any NVH or Disk Thickness Variation (DTV). However, extreme circumstances, such as intensive heat applications exceeding 1000⁰C without a cooldown, or with sudden stop, may produce some NVH. For classic CCBs, premium car service centres have been known to claim that brand new recently tracked chopped CCBs have developed DTV, and requested 10,000$ fee needed to replace them.
That is not the case with continuous CCBs, which need to reach over 1500C to commence loosing structural integrity. But things could happen, wrong pads, poor DOT fluid state. If indeed DTV was to occur, a re-bedding procedure could or should remove the extra pad material and restore the smooth contact surface. If that proves unsuccessful, CMCMAT can facilitate a return to our technical centre, and reconditioning the surface, which can be done multiple times. Surface reconditioning is an unparalleled advantage that the new 3D Continuous CCBs offer versus the 40 year older chopped technology.
12. Are they noisy, do they squeal?
All crossed-drilled rotors have a characteristic “whoooot” that some clients love, and others may dislike. On a MacLaren, a Lamborghini or a Ferrari this sound is present but often exceeded by their V8-V12 engine decibel levels. Noisier V6 or inline 6 engines (BMW M) reduce the cross-drilled sound, but it is perceptible. However, the newer generation of client vehicles, with insulated cabin acoustics and quieter engines, may indeed permit more of the cross-drilled sound entering the cabin. A BMW M Performance inline 6 cannot supress the CCB cross-drilled sound in the same way the V12 Lambo does at idle. Clients that are sure not wanting any additional sounds should opt for the non-drilled rotor versions.
Forums and videos document that classical CCBs have given their owners squeal related headaches for many years, even though most times their cars are driven in optimal weather. Some owners driving classical CCBs have been told that it is normal, “Live with it”, or lost countless service days trying replacements. In their case, squeal is caused by improperly bedded in brakes resonating, or just material vibration between their particular pads and OEM chopped fibre CCBs.
However, our 3D Continuous clients have reported no squeal during summertime torrential rain conditions, no squeal during cold morning startup, no squeal in 0C icy rain condition, no squeal as low as -30⁰C. This could be due to the material properties of 3D Continuous CCB its CoF and surface characteristics.