Feb 24, 2006 11:24:31 AM
- Avantgarde
- Senior
-
- Loc: City State
- Posts: 708, Gallery
- Registered on: Apr 6, 2005
Porsche Ceramic Carbon Brakes - Boon or bane?
Not sure if this is the right place to post this but here it goes.....extracted from another forum.
"Ok, lets nut it out once and for all...
I say that we would ALL feel the benefit of using carbon ceramics, some for their longevity and low dust/dust free use, some for appearance, and some for performance..." - ferrarifixer
"There's a very common misconception that upgrading brakes will automatically *reduce braking distances*. Nope. The car's ability to stop is a result of a variety of factors, the two biggest, by far, are the car's weight and the car's TIRES. A Ford Crown Victoria on racing slicks with stock brakes will outbrake the same car with giant brakes on street tires.
Heck, a Crown Vic with racing slicks and stock brakes will outbrake a Lotus Elise with giant brakes on snow tires!
Race cars have big brakes not because they're needed for the shortest possible braking distance, but rather to handle and dissipate heat and take the abuse of being used constantly. Take a 355 for example. With cold brakes, you'll get EQUAL braking distances with stock brakes versus big Challenge brakes or 8 piston Brembos (yes, you'll get different "bite" and "feel", but the distance will be the same).
After all, when you hit your brakes hard, you can lock up the tires (assuming no ABS). So the LIMIT isn't at the BRAKE, but rather at the TIRE.
If your brakes are strong enough to lock up the tires, then making your brakes bigger or upgrading them to ceramics will NOT decrease your stopping distance. Analogy: you've got a weight suspended by a cable tied to a wire tied to a string tied to a rafter. No matter how strong you make the cable, or the wire, the total weight that can be supported is always going to be limited by the string.
Now, having said that... where ceramic brakes - and bigger brakes, for that matter - do have beneficial effect is handling FADE. (and lighter brakes is also good, for handling, especially as it's unsprung weight, but that's not what we're discussing here; we're assuming that the car weighs the same, though if the ceramic brakes make the whole car lighter, it would theoretically create a shorter stopping distance, but I seriously doubt it would be a material amount.) Back to fade. On the street, if you have modern brakes on something smaller than a Freightliner, you're NOT going to have brake fade. Ok, ok, if you're coming down a mountain and ride the brakes the entire way down, you might get brake fade. But, realistically, on a modern car, the brakes are so good, you won't have any problems.
As for track use - sure, ceramic brakes might be an improvement, but that depends on how hard you're driving, how good you are, and what your setup is. For a 355 Challenge, with the massive rotors and decent ducting, it takes a LOT of use before you generate enough heat to worry about fade. Now, keep in mind, a less-skilled driver CAN easily cook brakes at the track. I've had students in even track-prepared cars boil fluid in just a handful of laps, simply because they're using the brakes incorrectly - braking too early, braking too long/extending the braking zone, failing to let the brakes cool, riding the brakes all the way to the apex, etc.
If anyone really is looking to improve braking performance, the best bang-for-the-buck way to do it is in this order (aside from learning how to drive):
1. Tires.
2. Better (fresh) fluid.
3. Better pads
4. Increased ducting.
5. Then and only then, upgrading the hardware." - Dennis aka BIGHEAD
http://www.ferrarichat.com/forum/showthread.php?t=94054&highlight=Ceramic
http://www.starfiresystems.com/news/...der_May_05.pdf
http://www.engineeringtalk.com/news/sur/sur114.html
Hope to hear more objective responses and discussions at Rennteam.
"Ok, lets nut it out once and for all...
I say that we would ALL feel the benefit of using carbon ceramics, some for their longevity and low dust/dust free use, some for appearance, and some for performance..." - ferrarifixer
"There's a very common misconception that upgrading brakes will automatically *reduce braking distances*. Nope. The car's ability to stop is a result of a variety of factors, the two biggest, by far, are the car's weight and the car's TIRES. A Ford Crown Victoria on racing slicks with stock brakes will outbrake the same car with giant brakes on street tires.
Heck, a Crown Vic with racing slicks and stock brakes will outbrake a Lotus Elise with giant brakes on snow tires!
Race cars have big brakes not because they're needed for the shortest possible braking distance, but rather to handle and dissipate heat and take the abuse of being used constantly. Take a 355 for example. With cold brakes, you'll get EQUAL braking distances with stock brakes versus big Challenge brakes or 8 piston Brembos (yes, you'll get different "bite" and "feel", but the distance will be the same).
After all, when you hit your brakes hard, you can lock up the tires (assuming no ABS). So the LIMIT isn't at the BRAKE, but rather at the TIRE.
If your brakes are strong enough to lock up the tires, then making your brakes bigger or upgrading them to ceramics will NOT decrease your stopping distance. Analogy: you've got a weight suspended by a cable tied to a wire tied to a string tied to a rafter. No matter how strong you make the cable, or the wire, the total weight that can be supported is always going to be limited by the string.
Now, having said that... where ceramic brakes - and bigger brakes, for that matter - do have beneficial effect is handling FADE. (and lighter brakes is also good, for handling, especially as it's unsprung weight, but that's not what we're discussing here; we're assuming that the car weighs the same, though if the ceramic brakes make the whole car lighter, it would theoretically create a shorter stopping distance, but I seriously doubt it would be a material amount.) Back to fade. On the street, if you have modern brakes on something smaller than a Freightliner, you're NOT going to have brake fade. Ok, ok, if you're coming down a mountain and ride the brakes the entire way down, you might get brake fade. But, realistically, on a modern car, the brakes are so good, you won't have any problems.
As for track use - sure, ceramic brakes might be an improvement, but that depends on how hard you're driving, how good you are, and what your setup is. For a 355 Challenge, with the massive rotors and decent ducting, it takes a LOT of use before you generate enough heat to worry about fade. Now, keep in mind, a less-skilled driver CAN easily cook brakes at the track. I've had students in even track-prepared cars boil fluid in just a handful of laps, simply because they're using the brakes incorrectly - braking too early, braking too long/extending the braking zone, failing to let the brakes cool, riding the brakes all the way to the apex, etc.
If anyone really is looking to improve braking performance, the best bang-for-the-buck way to do it is in this order (aside from learning how to drive):
1. Tires.
2. Better (fresh) fluid.
3. Better pads
4. Increased ducting.
5. Then and only then, upgrading the hardware." - Dennis aka BIGHEAD
http://www.ferrarichat.com/forum/showthread.php?t=94054&highlight=Ceramic
http://www.starfiresystems.com/news/...der_May_05.pdf
http://www.engineeringtalk.com/news/sur/sur114.html
Hope to hear more objective responses and discussions at Rennteam.
Thanks
And may I add something: being able to brake very very late actually makes you faster.
Personally, I see it as buying Insurance. 
