QUOTE=DZeckhausen;2461338]We’ve known for a long time that StopTech was developing a carbon ceramic rotor option for their big brake kits. Last month, the 700hp Callaway C16 Speedster was introduced at Pebble Beach and it featured the new StopTech ceramic brakes. Our turn to try these came just two weeks later, when we received a set for evaluation on a BMW E46 M3. This is a very big change in technology. Rather than using chopped carbon fibers, it’s made from a continuous fiber. This makes the StopTech rotors stronger than ceramic offerings from companies like Porsche, and less prone to oxidation - meaning they are more track friendly. We received four 355x32mm carbon ceramic rotors, mounted on billet aluminum hats and special brake pads in street and race compounds that are compatible with the exotic rotors.
First impressions out of the box? These are very strange looking rotors. They weigh only 9.6 pounds (including hats and hardware) and they don’t feel real when you hold them in your hands. They feel more like those plastic rapid prototypes that you have made on a computer controlled milling machine to see what a 3D version of your product is going to look like when it’s done. But these are the real thing and they are supposed to stop the car! Of course, the first thing we did was weigh them.
StopTech 355x32mm iron rotor and hat weigh a combined 16.8 pounds (2.2 pounds less than stock)
StopTech 355x32mm ceramic rotor and hat weigh a combined 9.6 pounds (9.4 pounds less than stock!)
The test car had already been upgraded to a 4-wheel StopTech kit a couple of years ago, so we decided to take advantage of the chance to swap the 4-piston front calipers for the new ST-60 6-piston calipers. What the heck? We were pulling the calipers off anyway and I had a few 6-piston kits in inventory.
The ST-60 calipers dwarf the ST-40 calipers
So off came the ST-40 calipers and iron rotors and on went the carbon ceramic rotors.
New brackets were required to mount the ST-60 calipers.
Then the calipers were mounted and the front brakes bled. This was not a difficult swap.
Next, it was time to swap the rear rotors.
After bleeding the brakes and putting the wheels back on, it was time to take the car out on the road. I had no idea what to expect. I thought there would be an abrasive feel between the pads and the rotors. And I thought it would make some strange noises. It did neither. Braking was completely smooth and totally silent. The initial bite for the first few stops was terrible, but it quickly improved, especially after the first bedding session. After a second bedding session, the bite was better than it had been with the Axxis Ultimate pads and the iron rotors. This is very nice.
What’s even more interesting is the effect of removing such a large amount of rotating mass. From the previous StopTech rotors, we shed more than 36 pounds of rotating mass. This is a difference you can feel in the way the car handles, accelerates, and brakes. I can’t wait to get a set of these on my SRT8 (15" StopTech BBK) and my 540i 6-Speed (14" StopTech BBK).
I waited two full weeks before posting anything, to see if there were any issues. No noises cropped up and the brakes continued to feel better as the miles racked up. Unlike the Porsche PCCB system, these don’t squeal when cold. And StopTech tells us these are better than the Porsche system at the track. We’ll see. StopTech sent us some track pads to try out, so the plan is to hit Lime Rock or Watkins Glenn in the next month or so and see how these feel at the track. I’ll report back after the track sessions.
Here’s a parting beauty shot:
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