RX7Club.com - Mazda RX7 Forum - Carbon Ceramic Brakes

Hi Guys,

This was originally posted in the brakes section but I figured there'd be more interest here so I've taken the information and condensed it here.

I've been looking to see if I could get a carbon ceramic brakes developed for the FD. I currently work as an aerospace engineer and we've been using them in aircraft landing gear (carbon-carbon discs) for a while. Long story short, I've been in touch with the manufacturer (J&C of Korea) of the carbon-carbon brakes for our landing gear and it turns out they also are the suppleirs for brembo (who supplies ferrari, porsche, and corvette zr-1) for carbon ceramic brakes.

After looking at some designs I was quoted $2200 :shocking: per rotor. Now I know that sounds ridiculous but considering that OEM from porsche/ferrari is $8000 per rotor, this is a huge cost savings.

If we get large quantities (unlikely) the price is going to look as follows:

Quote:

I would like to suggest you as below.
1. $2,100.00 for 100
2. $2,000.00 101-200
3. At the above price for 320-360mm, but
$2,300.00 for more than 380mm.
By the way, for the caliper that we have developed already, it shall be $250.00/each.

Here are the advantages of carbon ceramic brakes:

During an aggressive application of the brakes, the rotor temperature may rise to 1000-degrees C (1800-degrees F) before stabilizing in the 500-750-degrees C (900-1400-degrees F) range. The host vehicle must be carefully developed to route vast amounts of heat away from the spinning CCM rotors.

CCM has 85 percent higher thermal capacity than iron and more than twice the thermal radiance. But since it has less than one-third of iron's density and only 40-percent of iron's conductivity, the heat accumulation in a CCM rotor is far lower, a boon to braking efficiency. In essence, CCM heats up and cools off much faster than iron. Thermal and fluid mechanical analyses are used to configure a CCM rotor's radial and lateral vent channels.

CCM rotors provide higher heat (fade) resistance, greater stopping torques, and significantly longer life than cast iron brake rotors. Their friction coefficient doesn't change much with temperature. They are also about half the weight of iron rotors, a characteristic with three-fold benefits: Acceleration is enhanced because of CCM's lower rotating inertia and because the car's total mass is reduced. The lighter unsprung weight with CCM rotors yields handling gains.

CCM rotors do not corrode and their normal service life is nearly 100,000 miles according to Brembo. In racing use-such as Ferrari Challenge-their useful life is shorter but still more than a 1000 miles of flat-out running.
Here is a litte more information on CCB's (taken from edmunds):
First, carbon fibers are blended with a resin containing carbon and silicon. The compound is then pressed into a mold to create the basic disc shape, including its internal cooling vents. Next, using carefully controlled heat (up to 3,000 degrees Fahrenheit), the resin in the disc is converted to silicon carbide, a material nearly as hard as diamond. This is the "ceramic" in "carbon ceramic." Finally, the center section of the brake rotor — typically made of stainless steel or aluminum — is pinned or bolted to the ceramic composite disc.

Specially formulated brake pads are used in combination with the ceramic composite discs. This is an important point: Whether we're talking about CCB or "conventional" brakes, the pads and the rotors work together to do the braking.

The benefits of CCB begin with the fact that they're lightweight — the discs being approximately 50 percent lighter than those made of cast iron. In the case of the Boxster S, checking the PCCB option drops the overall vehicle weight by 34.4 pounds.

Well, when it comes to vehicle dynamics, not all weight is created equal. The brakes — like the wheels and tires, the spindles and approximately half the weight of the suspension components — are unsprung weight, the portion of the vehicle's weight that isn't supported by its suspension.

Lightweight CCBs also improve a vehicle's acceleration, but the relationship is not straightforward. Because the brake rotors are, well, rotating, they require more energy to accelerate and decelerate than a non-rotating element of equivalent weight

Ceramic composite rotors are extremely durable. In fact, manufacturers claim that they'll never need replacement — at least with "normal" driving. They're also resistant to the kind of warping that leads to pedal pulsation — merely an annoyance in the "real world," but a noticeable performance issue on the track.

The single greatest benefit of CCBs, however, is their resistance to brake fade. With repeated use — especially at high speeds — brake temperatures can rise dramatically, causing performance to drop off. This is a common occurrence during racing, but can also occur if you ride your brakes down a long mountain grade rather than downshifting to take advantage of engine braking. In either case, the consequences can be disastrous. Unlike conventional brakes, CCBs are designed for outstanding performance at very high temperatures

An SAE white paper on carbon ceramic brakes cooling efficiency:
http://www.sae.org/events/bce/presen...6wuellner3.pdf

Anyone else interested in getting a set for the track? :egrin: