RCF is Faster than the M4 and Audi RS5 on a Closed Track
11-15-14, 07:22 PM
#61
What we know about CCB rotors is that they dissipate heat very quickly so brake parts don't get deformed with high temperature during repeated hard stops which in turn provide consistent performance.
Steel brakes took longer to cool down from the same temperature, so they faded on repeated hard stops because they could not recover. If given enough time in between hard stops, steel brakes should not fade at all.
11-15-14, 08:21 PM
#62
Can you provide backup to the bold part? What kind of temperature are we talking about?
What we know about CCB rotors is that they dissipate heat very quickly so brake parts don't get deformed with high temperature during repeated hard stops which in turn provide consistent performance.
Steel brakes took longer to cool down from the same temperature, so they faded on repeated hard stops because they could not recover. If given enough time in between hard stops, steel brakes should not fade at all.
What we know about CCB rotors is that they dissipate heat very quickly so brake parts don't get deformed with high temperature during repeated hard stops which in turn provide consistent performance.
Steel brakes took longer to cool down from the same temperature, so they faded on repeated hard stops because they could not recover. If given enough time in between hard stops, steel brakes should not fade at all.
Last edited by PatrickISF; 11-15-14 at 08:30 PM.
11-15-14, 08:40 PM
#63
Marketing over science and engineering. Nice pick.
Here's a great primer written by a guy who has forgot more than the sum of Club Lexus knows about braking systems. He wrote it in 1991 for Grassroots Motorsports Magazine, but it is timeless.
http://www.scirocco.org/faq/brakes/p...n/pfpage1.html
Here's a great primer written by a guy who has forgot more than the sum of Club Lexus knows about braking systems. He wrote it in 1991 for Grassroots Motorsports Magazine, but it is timeless.
http://www.scirocco.org/faq/brakes/p...n/pfpage1.html
4) Compliance: Any changes that you can make to your braking system to reduce compliance will increase the overall efficiency of the system--improving pedal feel, wear, and stop-to-stop consistency. Think of it as balancing and blueprinting your braking system. Brake system modifications have their place to help make your ride more consistent, predictable, and user-friendly;
When this happens, the driver can confidently apply the brakes later, and this has nothing to do with shorter stopping distance.
11-15-14, 08:44 PM
#64
Tech Info Resource
iTrader: (2)
This video illustrates it best.
LFA on cold brakes with ceramic brakes accelerated quicker, but braked 2 feet longer than the R8 V10 with steel brakes.
Then on the second run, LFA's brake now with some heat in them stopped shorter than its first run while R8 V10 with steel brakes stopped 17 feet longer than its first run.
Pro race car drivers also explaining why LFA was getting better on second run with carbon ceramics and why R8 V10 was getting worse with steel brakes suffering fade after just one run.
Irrefutable real world proof of how carbon ceramic brakes get better and better as they heat up while steel brakes (even as huge as the one's on the R8 V10) rapidly fade.
LFA on cold brakes with ceramic brakes accelerated quicker, but braked 2 feet longer than the R8 V10 with steel brakes.
Then on the second run, LFA's brake now with some heat in them stopped shorter than its first run while R8 V10 with steel brakes stopped 17 feet longer than its first run.
Pro race car drivers also explaining why LFA was getting better on second run with carbon ceramics and why R8 V10 was getting worse with steel brakes suffering fade after just one run.
Irrefutable real world proof of how carbon ceramic brakes get better and better as they heat up while steel brakes (even as huge as the one's on the R8 V10) rapidly fade.
Carbon brakes have a higher Cf when hot. Current carbon brakes are able to lock the wheels on the first stop when cold. If they could not, then no manufacturer could put them on a street car. Carbon carbon brakes have been in racing since the 80's. They have only recently made it to street use for this exact reason.
But of course, we can assume the tires maintained the exact same traction for all stops despite them gaining heat and air pressure with each successive stop.
Please stop making claims about things you have not experienced or actually understand. Read the information from real engineers who design and build braking ans stability systems for the OEMs. It will help you stop making silly statements about the features of the brakes actually impacting stopping distance.
11-16-14, 02:49 AM
#65
Forum Administrator
iTrader: (2)
Guys need for you to keep this conversation respectful or stop posting in this thread. No more "silly" and "irrefutable"; this topic has a lot of variables, perspectives and no clear answers other than the unsprung weight advantage.
Quick google of BMW forums have a 300+ post thread debating the same thing, here is a really good post with a excellent quote of an earlier summary of points in that thread and an interesting link to a C&d test I hadnt seen before http://f80.bimmerpost.com/forums/sho...&postcount=245
Again, keep this thread mature if you choose to reply, knock off the personal comments.
Quick google of BMW forums have a 300+ post thread debating the same thing, here is a really good post with a excellent quote of an earlier summary of points in that thread and an interesting link to a C&d test I hadnt seen before http://f80.bimmerpost.com/forums/sho...&postcount=245
Again, keep this thread mature if you choose to reply, knock off the personal comments.
11-16-14, 03:35 PM
#66
Lexus Champion
Thread Starter
Guys need for you to keep this conversation respectful or stop posting in this thread. No more "silly" and "irrefutable"; this topic has a lot of variables, perspectives and no clear answers other than the unsprung weight advantage.
Quick google of BMW forums have a 300+ post thread debating the same thing, here is a really good post with a excellent quote of an earlier summary of points in that thread and an interesting link to a C&d test I hadnt seen before http://f80.bimmerpost.com/forums/sho...&postcount=245
Again, keep this thread mature if you choose to reply, knock off the personal comments.
Quick google of BMW forums have a 300+ post thread debating the same thing, here is a really good post with a excellent quote of an earlier summary of points in that thread and an interesting link to a C&d test I hadnt seen before http://f80.bimmerpost.com/forums/sho...&postcount=245
Again, keep this thread mature if you choose to reply, knock off the personal comments.
This competitive spirit is actually great for the industry as it continues to force Yaguchi and the Germans to produce even better racers.
It's all good.
Last edited by ISF001; 11-16-14 at 03:39 PM.
11-17-14, 06:23 AM
#68
Lead Lap
Yes, I can believe what I want and definitely they make a substantial difference. It is not a debate of which brake make the cars stop shorter. It is a debate of which brake works best on the race track. Tons of experts and race car drivers say the something. It is indeed based on science and engineering of how carbon ceramics brake better and better as they get hotter as opposed to steel brakes fading as they got hot.
Not only resistance to brake fade due to carbon ceramics, in the case of M4, if you think clamping force of 6 pistons front and 6 pistons back does not make a difference compared to 4 pistons front and 2 pistons back then that is laughably ridiculous.
I will leave it at that.
Not only resistance to brake fade due to carbon ceramics, in the case of M4, if you think clamping force of 6 pistons front and 6 pistons back does not make a difference compared to 4 pistons front and 2 pistons back then that is laughably ridiculous.
I will leave it at that.
The only advantage of CCB in this situation is weight saving IMO.
11-17-14, 02:31 PM
#71
Rotational weight is saving is worth much more than static weight. Rays Engineering, according to their testing, stated that 1kg of rotational/unsprung weight can worth AS MUCH AS 15kg in static weight. So the 60lbs lighter in rotors is a major different.
11-17-14, 08:38 PM
#73
Yes, but it the drivetrain doens't have to rotate the weight of the calipers. More power is delivered to the ground when you lighten rotational weight, 60 lbs is huge. Look at what the Evo did with just 9.3 lbs reduction. I would like to believe that with lighter rotors, it would be easier for the car slowdown/stop too
Quite a few of you have been following Shawna's Evo and the Tests we have been using it for. Last week she told me it was in need of brakes.
A while back we opened an account with Baer while they were still selling their two piece Evo rotors (two years ago). When we did that we purchased what we were told was the last of them. While I knew that's what I wanted to use for this project, they were simply not available any more. Long story short a quick phone call to Baer got us a few sets of rotors at our door a couple days later. They never put them back into production but "found" a few more rotors and decided to make hats for them.
Today we decided to test them, just as David did before. I remember a bunch of people not believing his tests before so we decided to do it again! This is what we found.
We strapped the car down and did a pull with the stock rotors: 313 TQ / 327 HP
Then actually jacked the car up ON THE DYNO and changed the rotors and ended up at 339 HP / 319 TQ. That's +12 HP and +7 TQ.
Weight:
Baer Front Rotor: 15.8 vs stock 17.75 = 1.95 each
Baer Rear Rotor: 11.75 vs stock 14.45 = 2.70 each
9.3 pounds of rotational weight savings going from a half worn set of stock rotors to these.
http://www.evolutionm.net/forums/evo...ht-rotors.html
A while back we opened an account with Baer while they were still selling their two piece Evo rotors (two years ago). When we did that we purchased what we were told was the last of them. While I knew that's what I wanted to use for this project, they were simply not available any more. Long story short a quick phone call to Baer got us a few sets of rotors at our door a couple days later. They never put them back into production but "found" a few more rotors and decided to make hats for them.
Today we decided to test them, just as David did before. I remember a bunch of people not believing his tests before so we decided to do it again! This is what we found.
We strapped the car down and did a pull with the stock rotors: 313 TQ / 327 HP
Then actually jacked the car up ON THE DYNO and changed the rotors and ended up at 339 HP / 319 TQ. That's +12 HP and +7 TQ.
Weight:
Baer Front Rotor: 15.8 vs stock 17.75 = 1.95 each
Baer Rear Rotor: 11.75 vs stock 14.45 = 2.70 each
9.3 pounds of rotational weight savings going from a half worn set of stock rotors to these.
http://www.evolutionm.net/forums/evo...ht-rotors.html
Test:
Davenport Motorsports (www.davenportmotorsports.com) of Canada, wanted to see the dyno effects of running different wheels on cars. They took a factory 2012 Camaro SS and ran 3 dyno runs. They ran the first run with a set of aftermarket wheels, the 2nd run with a set of stock factory wheels and the 3rd run with a set of HRE P45S wheels, all in 20” sizes.
These results highlight the effects of rotational inertia on drive-train losses (the hp lost between the engine crank and the ground). Wheels and tires contribute to drive-train losses as energy is used to spin up the wheels (and decelerate the wheels under braking). From the dyno chart you can see the effect of replacing factory wheels with lighter HRE wheels and see the negative effects of installing heavier aftermarket wheels.
Results:
1. (Blue curve) Factory wheels: 20”x9.0” with Pirelli 275/40-20 tires weighing 68 lbs combined per rear wheel. – Max hp: 371 hp, Max Torque: 375 ftlbs - (Baseline)
2. (Red curve) Aftermarket wheels: 20”x9.0” with Pirelli 275/40-20 tires weighing 72 lbs combined per rear wheel – Max hp: 369 hp, Max Torque: 373 ftlbs - (A [-] loss of 2 hp and 2 ftlbs)
3. (Green curve) HRE wheels: 20”x11.0” with Nitto 315/35-20 tires weighing 60 lbs combined per rear wheel – Max hp: 380hp, Max Torque: 384 ftlbs - (A [+] gain of 8 hp and 9 ftlbs and that is running a 2” wider wheel/tire combo)
Conclusion:
The engine obviously still cranks out the same amount of hp and torque, the lighter HREs simply waste less of it before it gets to the ground. Also interesting to note is that the gains are not just peak gains, but gains across the entire rev range. If they had done a braking test, we would have seen similar results as the rotational inertia effects also have a significant effect on how much energy is used to stop the wheel/tire combo vs. stopping the car. We talk about these effects all the time and focus on designing lightweight wheels with low rotational inertia, but it isn’t every day that you get to see real hard data showing the true effects.
Read more: http://mbworld.org/forums/c63-amg-w2...#ixzz3JOJzwcTN
http://mbworld.org/forums/c63-amg-w2...orsepower.html
Davenport Motorsports (www.davenportmotorsports.com) of Canada, wanted to see the dyno effects of running different wheels on cars. They took a factory 2012 Camaro SS and ran 3 dyno runs. They ran the first run with a set of aftermarket wheels, the 2nd run with a set of stock factory wheels and the 3rd run with a set of HRE P45S wheels, all in 20” sizes.
These results highlight the effects of rotational inertia on drive-train losses (the hp lost between the engine crank and the ground). Wheels and tires contribute to drive-train losses as energy is used to spin up the wheels (and decelerate the wheels under braking). From the dyno chart you can see the effect of replacing factory wheels with lighter HRE wheels and see the negative effects of installing heavier aftermarket wheels.
Results:
1. (Blue curve) Factory wheels: 20”x9.0” with Pirelli 275/40-20 tires weighing 68 lbs combined per rear wheel. – Max hp: 371 hp, Max Torque: 375 ftlbs - (Baseline)
2. (Red curve) Aftermarket wheels: 20”x9.0” with Pirelli 275/40-20 tires weighing 72 lbs combined per rear wheel – Max hp: 369 hp, Max Torque: 373 ftlbs - (A [-] loss of 2 hp and 2 ftlbs)
3. (Green curve) HRE wheels: 20”x11.0” with Nitto 315/35-20 tires weighing 60 lbs combined per rear wheel – Max hp: 380hp, Max Torque: 384 ftlbs - (A [+] gain of 8 hp and 9 ftlbs and that is running a 2” wider wheel/tire combo)
Conclusion:
The engine obviously still cranks out the same amount of hp and torque, the lighter HREs simply waste less of it before it gets to the ground. Also interesting to note is that the gains are not just peak gains, but gains across the entire rev range. If they had done a braking test, we would have seen similar results as the rotational inertia effects also have a significant effect on how much energy is used to stop the wheel/tire combo vs. stopping the car. We talk about these effects all the time and focus on designing lightweight wheels with low rotational inertia, but it isn’t every day that you get to see real hard data showing the true effects.
Read more: http://mbworld.org/forums/c63-amg-w2...#ixzz3JOJzwcTN
http://mbworld.org/forums/c63-amg-w2...orsepower.html
11-21-14, 05:21 PM
#74
Lexus Champion
Thread Starter
Here is the AMCI testing between RCF, M4 and RS5
Lexus RCF AMCI Final Master ProResHQ Brightcove Youtube - YouTube
Lexus RCF AMCI Final Master ProResHQ Brightcove Youtube - YouTube
11-21-14, 07:47 PM
#75
Lexus Test Driver
