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I keep hearing this but it hasn't been my experience nor a few friends that I saw go from noobs to turning in pretty good laptimes. we all went from aggressive street pads holding up ok when we were starting out and had long gradual brake zones to them fading in a lap or 2 as braking got harder and brake zones got shorter...
now that I looked at your link:
it supports what I'm saying. there is a difference between case 1 and 2, but its tiny.. the harder braking does get a little cooler, but not what, 5-10 degree's, maybe 15? thats not enough to make a difference in fade over the course of a lap, I mean maybe like a small section of your next brake zone. But you'll still start seeing fade maybe like 3 seconds later based on the temp vs time and distance charts... and it'll be just a hair less fade, definitely not the difference between bad brake fade and 0 brake fade .
I'm not really understanding what case 3 is meant to represent... the description below the graph doesn't really match what the graph is showing.
don't get me wrong, I'm not saying hard braking is bad or the slow way around the track or anything... I just always thought the whole "brake harder for less fade" thing was BS, and I honestly can't believe you didn't come to the same conclusion after doing that test.
I think you missed an important piece of info: lap time. Case 2 is faster than Case 1. Case 3 is equal to Case 1 in lap time, but uses the harder and shorter braking which results in lower rotor temps. The first two sentences in my conclusion paragraph:
The lesson here is that harder braking is better. Either you end up going faster and have basically the same rotor temps, or you go the same speed with lower rotor temps as compared to being too light on the brakes.
It sounds like from you and your friends' experiences as noobs, y'all were going relatively quite slow. Then your speed picked up/lap times dropped significantly, picked up enough speed that you had to shed way more kinetic energy than the brakes could handle. Drive any car slow enough and the brakes won't fade and that sounds like your noob experience. That was my noob experience. I've instructed a handful of beginner level guys and all of them drove slow enough that stock brakes and pads held up. My little model didn't have that great of a lap time difference between between Cases 1 and 2, like around 4 seconds over 60 second lap. Say 60 seconds represents a fast driver. Then 64 seconds is still pretty quick. A noob time would be like 75 seconds and in this case, the brake temps would be way low even with dragged out braking lengths.
I think you missed an important piece of info: lap time. Case 2 is faster than Case 1. Case 3 is equal to Case 1 in lap time, but uses the harder and shorter braking which results in lower rotor temps. The first two sentences in my conclusion paragraph:
The lesson here is that harder braking is better. Either you end up going faster and have basically the same rotor temps, or you go the same speed with lower rotor temps as compared to being too light on the brakes.
It sounds like from you and your friends' experiences as noobs, y'all were going relatively quite slow. Then your speed picked up/lap times dropped significantly, picked up enough speed that you had to shed way more kinetic energy than the brakes could handle. Drive any car slow enough and the brakes won't fade and that sounds like your noob experience. That was my noob experience. I've instructed a handful of beginner level guys and all of them drove slow enough that stock brakes and pads held up. My little model didn't have that great of a lap time difference between between Cases 1 and 2, like around 4 seconds over 60 second lap. Say 60 seconds represents a fast driver. Then 64 seconds is still pretty quick. A noob time would be like 75 seconds and in this case, the brake temps would be way low even with dragged out braking lengths.
oh, so you're comparing the case 1 and 3 temps, not 1 and 2?
On Case 3, it goes up to 55 m/s like the other two cases, but then drops to the speed required to match the time of Case 1
you say "drops to the speed required to match the time of Case 1" but case 1 stays at 55 and case 3 drops to 50, how is that the same? of course the brakes are gonna stay cooler if you start braking from a lower speed... or am I reading something wrong?
Case 1 and 2 have about the same temps, but Case 2 is a faster time, about 60 vs 64 seconds. Case 3 achieves the same time as Case 1 in the hypothetical lap, but manages to do it with lower rotor temps by braking later and harder.
Yea I want to get an AP racing break kit from URGE or Sakebomb but price is insane. Maybe in a year or two I will pick one up if I still have car.
I now have the full Urge/AP kit. However, you don't have to go that far, or to that much expense to address the issues described in this thread. Try this simple setup:
1. Girodisc 2 piece rotors, sized same as OEM, fit OEM calipers
2. New/rebuilt OEM Calipers
3. Inexpensive rear blanks
4. Cobalt XR2/XR4 pads
5. Brake ducts thru bumper to front rotors
6. Castrol SRF
I have won races, time trials and championships on this simple setup. No fade, very good pedal feel, no rotor cracking.
The pads are personal preference, but the Cobalts give excellent initial bite, and will teach hard initial application, which will lead you to learn early progressive brake release. They stand up exremely well to heat. I've run Cobalt, Carbotech, Hawk, PFC, and GLOC, and always go back to Cobalt. The less aggressive rear compound will help from overheating the rears, and minimizing heat transfer to the wheel bearings. The Girodisc's with brake ducts lasted me basically a full race season without cracking. They stand up to heat, and shed it well.
Replace/rebuild your calipers every other or every third year, depending on how much you're tracking. Simply, the heat wears on the seals. Eliminate this as a place where you could be losing brake power/feel.
Bleed the SRF well. I use a pump bleeder and the old fashioned method of pumping the pedal, both work. Given this, SRF is phenomenal. We use it in our endurance car too, and it lasts a rediculously long time (whole season in the s2k) with no fade or mushiness.
None of the above will ever make the system as rock hard as a fixed caliper setup. However, it'll be very close for a lot less money, and is more than enough to win races with.
Lastly, when draining the fluid, or replacing calipers, you will never get the ABS system fully bled. The solution is to go out and engage ABS multiple times (in a safe place on the track), in multiple sessions. It seems to take about 5 full 20-30 minute sessions to fully clear the ABS, and before I have confidence that I won't hit a stray air bubble in the system. Check fluid, and bleed once or twice during those initial sessions.
Last edited by BlueBarchetta; 01-04-2018 at 05:43 PM.
Case 1 and 2 have about the same temps, but Case 2 is a faster time, about 60 vs 64 seconds. Case 3 achieves the same time as Case 1 in the hypothetical lap, but manages to do it with lower rotor temps by braking later and harder.
How is 1 and 3 doing the same hypothetical laptime if 3 is going slower? the 55m/s vs 50m/s?
I'm surprised so many people are happy with the motul rbf600. I thought pedal feel was terrible after just a single track day, I prefer ATE over the rbf600
How is 1 and 3 doing the same hypothetical laptime if 3 is going slower? the 55m/s vs 50m/s?
I did have Case 3 go up to 55m/s on the acceleration just to make my simple model more simple, but then basically instantly drop to 50m/s. Where Case 3 makes up ground on Case 1 is under braking. I used my crazy MS snipping skills to draw in the area under the curve where Case 3 is going faster than Case 1 because it carried the speed deeper before braking. This also shows the classic over-taking maneuver under braking of course.
I did have Case 3 go up to 55m/s on the acceleration just to make my simple model more simple, but then basically instantly drop to 50m/s. Where Case 3 makes up ground on Case 1 is under braking. I used my crazy MS snipping skills to draw in the area under the curve where Case 3 is going faster than Case 1 because it carried the speed deeper before braking. This also shows the classic over-taking maneuver under braking of course.
well then one can argue the lower temps are more from braking from a lower speed and not so much from braking harder. besides, the goal is case 2 anyway, the faster lap...
The quicker your lap times the faster you are at the braking zones all around the course. Brake energy absorbed isn't linear with speed. K = 1/2mv^2 where K is kinetic energy, m is mass in kilograms, and v is velocity in meters per second and that's "velocity squared" not velocity * 2. As you get faster you generate a crap-ton more brake heat.
Your cooling times also are reduced as you get quicker. If you're not recording lap times you don't know how slow you are
I have the same problem for MY05. stop tech rotors stock calipers with hawk hp+ on the fronts... its not consistent but I do from time to time get that fade.
01-04-2018, 11:48 AM
