AP Racing brake systems in development

[GTB/ZR-1]

^^^

Good to know that the popular pads are available.

I may go w/ AX6s for my streetie/AutoX setup.

Thx

[D1cker]

I bought mine with some ferodo ds2500 for the street

[OrbitalEllipses]

GTB/D1cker, those are great compounds but I found both to be rather dusty. That's just the trade off for higher Cf street pads.

[Dave-ROR]

Originally Posted by Paragon

Does anyone run the C300 pads on the street? Are they very noisy?

Extremely. Do not use the C300s on the street.

[Dave-ROR]

Here's some current pics of mine, with rotor temp paint and caliper temp strips...

This past weekend I was at Sebring, saturday running AP C300s up front and Sunday running CL RC6E's up front.

First four pics are from saturday, so post 2 hours of usage on the track with AP C300s up front.

Driver side rotor temp paint/rotor:


Driver side caliper temp strip:


Pass side rotor temp paint/rotor:



Pass side caliper temp strip:


The next four pics of from this morning, about 1.5 hours on the track Sunday with CL RC6E plus street driving on CL RC6E pads. I haven't taken the wheels back off yet so I'll update with better pics when I swap back to AP S100 street pads.

Driver side rotor temp paint/rotor:



Driver side caliper temp strip:



Pass side rotor:




Pass side caliper temp strip:


I was late braking more with the CL's to try to overheat them. I failed. I did get the calipers a bit more toasty though I didn't really bed them in much either, didn't have time.

Oh and as a bonus a buddy of mine and myself picked pit spots right next to @JRitt's father in law. Jeff, he still wants a nice Essex hat, not just an AP hat

He has an AWESOME car and is a good guy We can thank him for Jeff's involvement in motorsports it seems like.

[JRitt]

Nice Dave...beat 'em up! :happy0180: You definitely got them good and toasty with the CL's. The CL's do tend to run a little hotter anyway, since they are sintered metal.

That's so funny about my father-in-law. He is a fantastic guy, and his daughter didn't fall too far from the tree. She actually used to autoX the original car that engine was in...a black '89 Carrera road car...she taught me how to drive stick my freshman year of college in her Mazda 323. I fell in love quickly. Back in '99 he took me out on Watkins Glen when he was up there for a club race. After that I went bat-sh*t goofy into motorsports, changing my career, my life, etc. I think I bought my Integra Type-R within a month of that ride.

[celica73]

Originally Posted by Dave-ROR

Here's some current pics of mine, with rotor temp paint and caliper temp strips...

This past weekend I was at Sebring, saturday running AP C300s up front and Sunday running CL RC6E's up front.

First four pics are from saturday, so post 2 hours of usage on the track with AP C300s up front.

Driver side rotor temp paint/rotor:

Dave can you outline the usage of the temperature paint? Is each segment applied before a particular session? I assume it is the Genesis Technologies stuff?

[Dave-ROR]

Originally Posted by celica73

Dave can you outline the usage of the temperature paint? Is each segment applied before a particular session? I assume it is the Genesis Technologies stuff?

http://www.essexparts.com/brake-disc-thermal-paint.html

I'm using AP Racing thermal paint. This was applied before the weekend, I didn't care so much about each session vs the max I could reach over the weekend. I hit 1,130°F on the outside facing rotor face within one real session. Not sure if the inners hit it or not, last check they didn't but I was harder on the brakes Sunday and I haven't pulled the wheels off to check yet.

[JRitt]

Hello Gents,
I wanted to check in and notify everyone of a new policy we are going to implement with our Competition Brake Systems. Moving forward, brake pads will NOT be included as part of the kit. We were including a set of AP Racing C300 Endurance pads, but we will not be anymore.

Why are we doing this you ask? Because everyone...and I do mean everyone...wants a different pad compound! Just about every customer I talk with wants a different flavor. In an attempt to keep the masses happy, we're going to allow our customers to choose any of the pads below that we offer, and add them on to their brake kit purchase for a $25 flat rate. Again, if you buy a Sprint or Endurance kit, you simply look at the list below, pick what fits you best, and pay $25 for one set. Any additional pad sets will be at regular retail price.

To be honest, this is a major pain in the you-know-what for us. We have to keep more inventory, and we can't keep fully built kits sealed on the shelf. We think it's worth it to give our customers what they want/need however.

If you don't want any of the pads we offer, and want to buy something different somewhere else (there are loads of other options on the market), that is fine also.

That said, there are a lot of really great pad varieties here, and something for everyone.:happy0180:

Please note:

• Sprint Kit uses D39,41, and 43 radial depth pads
  
• Endurance Kit is the only one that can use pads marked as D50 radial depth! At this time, only Ferodo and AP Racing are the only brands we sell offering the D50 size
• In other words, the Endurance Kit can use any of the pads in the list below, while the Sprint Kit can use any of the pads below except for the ones specifically designated as being D50

Thanks!

AP Racing S100 (D41 radial depth)
AP Racing C300 (D41 radial depth)
AP Racing S100 (D50 radial depth)
AP Racing C300 (D50 radial depth)
CL Brakes RC8
CL Brakes RC6
Ferodo DS2500 (D50, tall radial depth for more pad volume)
Ferodo DS3000 (D50, tall radial depth for more pad volume)
Ferodo DS1.11 (D50, tall radial depth for more pad volume)
Ferodo DSUno (D50, tall radial depth for more pad volume)
Ferodo DS2500 (D41 radial depth)
Ferodo DS3000 (D41 radial depth)
Ferodo DS1.11 (D41 radial depth)
Ferodo DSUno (D41 radial depth)
Hawk DTC-05
Hawk DTC-70
Hawk DTC-60
Hawk DTC-30
Hawk HT-10
Hawk HP+
Hawk Black
Hawk MT-4
Hawk HPS

[Huehuecoyotl]

Ok so i am back here, still looking to upgrade the brakes, now that I got my car back last week.

Well yesterday I squared up with Essex on the OE pad setup they sold me(and even shipped it without billing me by mistake), now its a race to wear out these pads asap

Why? cause next on my list is the Endurance upgrade, tho I am finding myself trying to talk myself out of it back towards the sprint. I was really hoping to find an objective review of someone who has driven both the sprint and endurance on similarly setup cars
... not that Jeff isnt objectove in his posts, but I just wanted to get a better idea of how they feel or perform different at the track, and , at the limits.
Does the endurance out break the sprint to the point of loosening the rear?
Does one lend itself to be more delicately modulated at the limits?
Is pedal feedback different between the two?

Feed me details, anyone who owns these, and sure, I'd love to hear more on these questions from Jeff

[Hanakuso]

Originally Posted by Huehuecoyotl

Ok so i am back here, still looking to upgrade the brakes, now that I got my car back last week.

Well yesterday I squared up with Essex on the OE pad setup they sold me(and even shipped it without billing me by mistake), now its a race to wear out these pads asap

Why? cause next on my list is the Endurance upgrade, tho I am finding myself trying to talk myself out of it back towards the sprint. I was really hoping to find an objective review of someone who has driven both the sprint and endurance on similarly setup cars
... not that Jeff isnt objectove in his posts, but I just wanted to get a better idea of how they feel or perform different at the track, and , at the limits.
Does the endurance out break the sprint to the point of loosening the rear?
Does one lend itself to be more delicately modulated at the limits?
Is pedal feedback different between the two?

Feed me details, anyone who owns these, and sure, I'd love to hear more on these questions from Jeff

Good point and i'm also interested. I haven't heard of any "feel" difference between the two. I always just looked at the specs, which the Endurance seems to handle cooling better which the additional vanes, size, integrated duct.

[JRitt]

Originally Posted by Huehuecoyotl

Ok so i am back here, still looking to upgrade the brakes, now that I got my car back last week.

Well yesterday I squared up with Essex on the OE pad setup they sold me(and even shipped it without billing me by mistake), now its a race to wear out these pads asap

Why? cause next on my list is the Endurance upgrade, tho I am finding myself trying to talk myself out of it back towards the sprint. I was really hoping to find an objective review of someone who has driven both the sprint and endurance on similarly setup cars
... not that Jeff isnt objectove in his posts, but I just wanted to get a better idea of how they feel or perform different at the track, and , at the limits.
Does the endurance out break the sprint to the point of loosening the rear?
Does one lend itself to be more delicately modulated at the limits?
Is pedal feedback different between the two?

Feed me details, anyone who owns these, and sure, I'd love to hear more on these questions from Jeff

Okay...here's my non-objective opinion.

Stopping Distance
The difference between the Sprint and Endurance kits is not a matter of one out-braking the other. If the systems are designed properly, and they both are, they should show nearly identical performance in terms of stopping distance (until they are both heat soaked). In other words, if we measured the stopping distance on a car with the same tires using both systems, they should stop in roughly the same distance. This is exactly what we did in our testing. Tires are what stop the car. Brakes are about managing heat!

Heat Capacity/Energy Conversion

Ultimately, the Endurance system has greater heat capacity. That is literally the only thing you gain with the Endurance system. It has larger discs, which can absorb more heat. It also has the built-in provision to attach a brake duct hose, which allows for cooling air and temperature reductions. The discs are floating in the Endurance system, meaning that when they do get hot, they can expand with less strain on the disc at the point where it attaches to the hat. Again, those are all related to heat. So, in a certain range of temperatures...from ice cold to fairly hot, performance between the Sprint and Endurance kits will be identical. Only when a massive amount of heat is introduced to the system will any differences between the two kits become evident.

So what happens when a massive amount of heat is introduced, and how would the two kits react differently? At some point, any brake system will run out of heat capacity. Brakes convert kinetic energy (a spinning disc) into thermal energy (the brake pads rub against the disc and generates friction). Energy is converted, not created. Depending on the disc size, pad volume, caliper design, cooling, etc., the conversion of energy happens at a certain rate, and the brake system has limitations on the rate at which it can convert energy. Here are the primary things that would push a brake system towards its limits of being able to adequately convert motion into heat.

• An increase in speed- Kinetic energy = mass x velocity (squared). As the car travels faster, the disc spins faster, and there is more energy that needs to be converted to heat. Since speed is squared in that equation, an increase in speed has the most dramatic impact on the amount of kinetic energy generated. In other words, if you add 200hp horsepower to your car, it will be have a far greater impact on your brake requirements than if you add a 200lb. passenger...and it will push your system towards its maximum heat capacity much more quickly.
• An increase in mass- Things in motion are harder to stop as their mass increases. The amount of leverage, torque, etc. to slow a heavy object is greater than what is required for light one. A freight train requires a very different brake system vs. a Lotus Elise.
• An increase in friction- The friction between the object in motion vs. what it is moving against makes a big difference as well. If you slide a book across a table, it slides easily. If you slide a book across a rubber mat, it won't go anywhere. The friction between the two objects is much greater. If you mash your brakes on race slicks, you have greater friction with the road vs. mashing the brakes on stock tires, which are far less sticky. With the race slicks and higher grip, you have a much greater capacity/ability to turn your motion into heat quickly.

So what does that all mean? It means that every car can find the limits of a certain brake system if it is made faster or heavier, or it is given more grip. Let's look at an example:

Little Timmy got his FR-S for Christmas. His paper route isn't earning him much chedda, so he has to leave his car stock. He goes to the track. It turns out Timmy is the next Kimi. He is super talented and fast. He is hitting high top speeds into the brake zones, and changing a lot of kinetic energy into heat. Since his stock pads aren't really designed for that, they melt (they're made to be quiet and work well cold). As they are melting, they smear all over his discs, giving him vibration and judder every time he hits the brakes. His discs are in the same boat...they don't move much air through them, and they are overwhelmed by the heat. They are cycling between extremely hot and cool, and they develop huge cracks. Since the pads and discs are not efficient at handling heat (they weren't made for that specifically), they are heat soaked. All of that heat has to go somewhere.

1. It radiates into the air around the brakes, sits in the wheels, etc.
2. It conducts- it transmit through the actual hard parts and metal. The wheel bearings get hotter, etc.
3. It soaks into the brake fluid through the caliper via convection

All of that pad and disc heat wears on the other parts around the brakes, and it soaks into the brake fluid making it boil. When it boils, air bubbles are produced. Since air bubbles can compress...the brake pedal is no longer rock hard as it should be.

So Timmy has some problems. His pads are melted, he has judder since they smeared all over his discs, his discs are cracking, and his brake pedal is soft because his fluid boiled. Timmy needs some help. He needs some brake components designed to handle high temperatures.

Timmy buys a Sprint Kit and a pyrometer to take disc temperatures, because he wants to learn more about vehicle dynamics, and he wants to get faster. He leaves everything else on the car stock, and goes out to Willow Springs raceway (a relatively easy braking track). The day goes great and he has a blast as he starts to realize that track driving is addictive. His discs were hitting 950F consistently, but he had no brake problems. The pads didn't fade, and his pedal remained firm all day. Timmy wants to go faster though, because all of the Corvettes were passing him all day. He goes out and buys some race slicks before his next event at Buttonwillow.

Timmy heads out to Buttonwillow. The race slicks allow him to get through the corners much more quickly, exit turns faster, and hit a higher speed at the end of the straights. He now has to go from a higher speed down to reach his corner entry speed, which transfers a lot more energy into heat. His driving skill is also steadily improving as he gets more experience. He's getting through the turns faster, and getting closer to his tires' ideal slip angle. He still can't catch the Z06 vettes, but he passed a couple of M3's and 911's. His brakes worked great all day, but when he was checking temps, he noticed that he was hitting 1200F consistently on his discs. He also saw a few spider cracks develop on the discs. By the last session of the day on Sunday, a lot of people had already gone home. He was out there with very little traffic in his run group, and he actually did 40 minutes straight instead of the usual 20 mins. At the very end of that last session, he started to feel a little softness in his brake pedal. When he went home and bled his brakes he noticed that a couple of air bubbles came out.

At this point, Timmy goes a little apesh*t. He decides that he is going to make the Z06's feel silly when they're passed by a lowly FT86. He installs a turbo kit that adds 150 whp. He goes back to Big Willow for his next event. Something similar to the last event happens, and they get the chance to run for an hour straight at the end of the day. He runs the car a full hour flat out, but doesn't have any brake troubles at all...no soft pedal, nothing. He doesn't see any air bubbles when he bleeds the brakes. He sets the fastest time of the day, passing a Gallardo down the front straight.

Back to Buttonwillow next time. Because he is so fast, Timmy runs in the fastest group. He goes out and tears it up in the first session. By the end of 20 mins. though, he's having some brake issues. At first he notices that even though his pedal is hard when he brakes, the car isn't slowing down like it's supposed to (brake pad fade). Uh oh. A few laps later, his pedal starts to get lower and lower going into brake zones...double uh oh. Timmy pulls into the hot pits and his friend zaps the front disc with the pyrometer. 1350F...ouch! Timmy wisely decides to go back out for a couple of cool down laps before the session ends, to get some air flowing through the brakes.

So what happened during Timmy's journey? He found the limits of his stock system quickly, as they were simply not designed for what he intended to do to them. Then he increased his car's ability to generate brake heat by adding better tires. He also improved his driving ability, allowing him to increase his speeds at the end of straights and pour even more heat into the system as he slowed from higher speeds. To offset those things, he installed a brake system specifically designed to handle the heat of heavy track use.
Ultimately though, he threw a bunch of HP at the car with his turbo, and radically changed the amount of energy being transferred from motion to heat. When he did so, he found the limits of the upgraded brakes.

Timmy sold his Sprint kit to his friend who didn't have any plans for forced induction. He ordered and installed an Endurance kit. Now he had larger heat sinks in the form of bigger discs. They could absorb more heat before transmitting it to other components. He also hooked up some brake ducting to the caliper brackets, allowing for more cooling air to get into the center of the disc, and pump air through them. Since the discs could now swallow and dissipate more heat, and his cooling ducts were bringing in a nice stream of cool air, his pads never got as hot...nor did his calipers...nor did his brake fluid. He went out to Buttonwillow and didn't have any problems at all.

A couple of points to note:

1. Every driver and track are different. What works well one place, may not be enough somewhere else, or with someone different driving.
2. Any brake system can find its limit with enough speed. It's just a matter of finding where that point is.

Choosing between the Sprint and Endurance kits is simply a matter of determining where you lie on Timmy's journey. At the time I write this, I have yet to hear of a single report of anyone running into any pad or fluid fade, premature disc cracking, etc. with the Sprint kit. That includes several forced induction cars, and loads of very fast drivers on tracks that are tough on brakes. Nobody has yet run into Timmy's problem with the Sprint Kit. It has been enough. That said, eventually, someone is going to take it too far due to too much power, too much speed, too much skill, too tough a braking track...you get the picture.



This is all leading up to my next post on brake feel.

[Huehuecoyotl]

...


And you say the Endurance kit is still 5lbs lighter than OE?

Moral of the story, Timmy got FI. Timmy exceeding most 'stage1' specs.

Timmy goes as fast as he can into turns, Timmy a noob who may overbrake.

Timmy want Endurance!

Timmy gonna call and place order, Timmy thinks, wow, Timmy see's the light...

Jeff, thank you. And thanks to Timmy, too.

[Hanakuso]

Originally Posted by Huehuecoyotl

...


And you say the Endurance kit is still 5lbs lighter than OE?

Moral of the story, Timmy got FI. Timmy exceeding most 'stage1' specs.

Timmy goes as fas as he can into turns, Timmy a noob who may overbrake.

Timmy want Endurance!

Timmy gonna call and place order, Timmy thinks, wow, Timmy see's the light...

Jeff, thank you. And thanks to Timmy, too.

I think it's 10lbs total for both sides