Dubstep Shep

I'm sure you're correct, but there's a question as to how much of each of those things it has over the AP Endurance setup. I'm all ears to hear the facts from an expert, but here's my take on some of this:

I doubt it's much lighter, especially considering the larger pads.
Bigger disks mean more rotating mass, especially if you have to go up a wheel size.
The titanium pistons could be retroactively added to the endurance setup.
The heat management is already pretty good on the AP Endurance setup. I'm not aware of anyone overheating them with a good ducting setup.
How much stiffer is the question here.
True, and I could see this being a huge benefit on an actual endurance race car like the C6R where not having to pit as often is a big advantage.

I understand they're superior, but diminishing returns plays a big part here. Those cars have custom control arms, body work, etc. that play as large as part as anything. Look at that picture of the C6R. It's ALL carbon fiber in there, with custom EVERYTHING. The AP endurance kit is probably way more brake than almost anyone except professional race teams could ever hope to need. Just my $0.02.

johnny c

we are on a subject close to my heart.





in this picture we are actually seeing is a poor heat distribution threw out a rotor. those bands are actually really bad to see. it's saying that the center of the rotor that has the most thermal capacity isn't being used as efficiently as it can be. not what you want from a $500K kit.

iberico

Are the DP cars using iron or carbon-carbon rotors? I can imagine it is a result of improper bedding or setup. Look at plenty of other red hot AP iron or carbon-carbon discs and the results speak for themselves. AP and Brembo are king of the hill with regards to braking and friction products and have the greatest use in all levels of motorsport & OE - by a long shot. I know you used to work for PFC so you may still have some vested interest there =)

0Anthony @ LGMotorsports

When you get into the hardcore race stuff, be it Brembo, AP, or Alcon you are going to see a lot of the similar stuff and similar pricing. I think the parts on the ALMS car back in 2008 were:

• $6700 ea caliper
• $985 ea rotor
• $1180 ea hat
• $1200 axle set for pads
• $150 wheel for hat / rotor hardware

That being said...with the 34mm thick pads on that car we could go almost 8 hrs green flag racing without changing a set of pads at Road Atlanta. Do you need a $35,000 brake kit to do HPDE's...no but for those that are going door to door at the limit for hrs on end...then yes you would.

Werks

You my friend need to get out of the shop a little and get some sun

0Anthony @ LGMotorsports

Hey now...I'm usually upright when at the track so I have a nice mechanic/farmer tan....only the top side where the uniform doesn't cover.

iberico

Paging Jeff Ritter! The GT/lemans/FIA spec CP6160 caliper is amazingly light at 5.5 lbs, especially considering it is much larger in size than the AP endurance 2-piece caliper with SS pistons. The 'budget' caliper weighs in at 7.49 lbs. Don't get me wrong, the endurance package is more brake than 99% of us can wish for in both street usage and track settings. You are right, those professional race teams have very high budgets and can opt for the best performance products money can buy. Basically it's "open checkbook" for those boys.

Thanks for the info

Isn't it weird how cultures differ? In Asia, people there WANT to stay fair/pale skinned. It goes back to the old days where the wealthy and elite stayed indoors while the poor villagers and laborers worked outside getting tanned and baked everyday.

iberico

Johnny, can you explain this on Schumacher's Brembo equipped Sauber C9?




Junk brakes on the Brembo equipped Ferrari FXX as well?



Same with the Brembo equipped 599XX? Honestly, I don't know nearly as much as you guys do about brakes so please edumacate me.

JRitt@essex

Hey guys,

Sorry, but that's unrealistic speculation. At any given moment it's far more common to see a disc that isn't glowing perfectly across every mm of its surface, vs. one that is. We see different pieces/bands of the disc glowing on the track, on our burnishing machine, and on our dyno. A lot of it depends on where the pad material is at any given time on the disc. The pad material migrates around the face of the disc constantly, and the pads create more friction in those areas, creating the glowing bands.
Also, maybe the pic above was taken early in the stopping event? Typically only part of the disc is glowing earlier in the stop, but as the disc gets hotter going deeper into the turn more of the disc glows.

JRitt@essex

Okay...the $20,000 question...just how much better are the absolute bleeding edge AP Racing Calipers vs. the Pro5000R. They are indeed stiffer, lighter, and have superior cooling. As mentioned however, it's a matter of diminishing returns. It's no different than the question of whether or not you need a supercomputer to surf the internet. Need? No. Want? Absolutely! Why wouldn't you want the baddest of the bad?

When millions of dollars of sponsorship money is on the line, ounces and mm count...a lot. In the elite ranks of motorsport, there are many different brake packages depending on the usage environment. In NASCAR Sprint Cup for example, they change discs and calipers like you guys change your shorts! :P Regardless of what track they're running, they always have the absolute least brake on the car that they can get away with. That means the smallest, lightest disc and caliper that will make it across the finish line. Then it can blow up on the cool-down lap. They're looking for ANY competitive advantage. Ounces here, and mm there, add up to potential wins and championships when there are hundredths of a second separating cars. Basically, everything is maxed out.

Also keep in mind that a purpose-built racecar leverages the entire system. They use an AP Racing caliper, disc, pedal box, and master cylinder. That whole chain is optimized, and the little advantages of one caliper over another become amplified. In other words, all of the tolerances are tightened up to near nothing, and the feedback the driver receives is more pure and unfiltered. Little changes are amplified.

Here's an example...two AP Racing six piston calipers below. The first is the the CP6169, which is AP's 'slimmed' Radi-CAL for GT cars. I had this one on my desk and we snapped some pics of it. It is ridiculously beautiful in person, and truly a piece of sculpture. It takes something like two weeks of machine time to cut this from a solid block of aluminum (monobloc design). It is designed to operate on a 378x32mm carbon disc...titanium pistons. It weighs 4.3 lbs.! Retail price= $7,000 per caliper.
















If you are at all mechanically inclined, or know anything about manufacturing or design, you honestly can't look at that and think anything other than, "holy. sh@t."

Now, here's our CP9668 caliper that we use in our standard, off-the-shelf Radi-CAL Competition Brake Kits for the C5, C6, and C7. It weighs 6.9 lbs., and we run it on a 372x34mm iron disc. It has ventilated stainless steel pistons. Retail price= $1399 per caliper









The above calipers are also gorgeous. They are also lighter and stiffer than anything else on the market. They are also art in my eyes, and when I first saw them I was stunned by how similar they look vs. AP's most expensive pieces (and all Radi-CAL's in between).

You have to also keep in mind that AP Racing is now on their Gen. 6 or Gen. 7 Radi-CAL designs. If you haven't read my article, "The AP Racing Radi-CAL Story," you should definitely check it out. You can see the early Radi-CAL's in that story, and then compare them to the one above. With each generation they get stiffer, lighter, and more sparse as AP evolves the design language. The Pro5000R is a current generation Radi-CAL. They look and perform every bit as wizzy, or more so, than the earliest Radi-CAL's, and it's a constantly evolving process. There's no caliper in the world that can be bought at anywhere near $1300 that is better than that caliper, period. They make competitors' calipers in that price range look incredibly primitive and antiquated.

So for the average enthusiast, are they going to find the CP6169 six to seven times better than the CP9668? No they aren't. If you were trying to secure a $20,000,000 sponsor by winning the championship this year, you'd probably take the chance that the CP6169 was superior by some magnitude if AP told you they were however. Just the 2 lbs. per caliper weight savings alone would be an enormous deciding factor in pro motorsports if all else were held equal.

For our typical enthusiast customer putting a kit on his production-based Corvette however, our Pro5000R Radi-CAL kits are all they could realistically want unless they are trying to accomplish something very specific, and were operating outside the normal conditions our customers encounter (most are literally not racing the 24 Hours of Le Mans, but we have them covered if they are).

The thing to keep in mind however is that proper platform integration is one of the toughest parts of a properly designed brake system. It's not just as simple as grabbing any pair of calipers and bolting them on the car. People who try to do that typically end up with empty pockets and some tears. If you buy a set of $14,000 brake calipers, you still need to figure out which discs to use them with. Then you need to adjust piston bores to match the OEM master, or you need a different MC. Then you need a proper bracket to mount the caliper on the car. Then you need a custom designed disc hat to orient the disc properly. Then you need to look at the rear end of the car and do the same thing. That's why our Competition Brake Kits are a tremendous value in the $2500-$4500 price range per axle. We figure all of the above out for you. It's like hitting the easy button. You get a huge % of the performance of AP's most elite hardware at a fraction of the cost.

Back to the original question...is there anything wrong with wanting the absolute best there is to offer? Heck no. If money was no object, I'd choose the brakes straight off the C7. They are better. They're stiffer, lighter, and run cooler. Actually, I'd just have Pratt & Miller build me an entire C7 and skip ahead with every other piece of the car as well. It's just a matter of how far you're willing to go, how exclusive you want your setup to be, and how much that last shred of performance is worth to you. Regardless of which route you go with AP Racing, you're still going to end up with superior brake performance than the guy next to you in the pits.

dvandentop

I have a kit for sale of some high end c6r compareable brakes

same cp6665 as was talked about earlier
Long pad life and amazing performance.

https://www.corvetteforum.com/forums...iston-kit.html

NoOne

Yes but will they stop the squealing noise everyone hates on the stock brakes?

iberico

Mr. Ritter, thank you for the very insightful post. That CP6169 is exactly why I love AP Racing so much. They are on the absolute cutting edge and way ahead of the competition with their Radi-Cal lineup. Other manufacturers caliper designs are, frankly in the industrial revolution still. Slight exaggeration but you know what I mean!

Personally, I prefer the style of the CP6160 caliper as it looks less alien-spacecraft-like and has a more refined appearance, especially with the delicious carbon duct. Not to mention, the nickel plating is a bit 'blingy' for me. How long does it take to manufacture a CP6160 caliper on the specialized CNC machines?

I would gladly hang up that CP6169 in my room, just as wall art.



That CP6665 caliper is the gold standard in DTM racing. Good luck with sale!

Mjolitor 68

Guess I'm mental enough

And yes the brakes are super strong

johnny c

i didn't say junk. just not perfect operation. Ideally we want to see heat directed toward the center of the rotor. where the rotor has the highest thermal capacity. if we are seeing heat bands on the outer and inner side of the rotor that is a read flag for me that there is an issues.




this is what we want to see in a well developed braking system. the heat even and using 100% of the rotor to gain maximum efficiency.

johnny c

it's perfectly realistic. it comes down mainly to caliper and pad design. i can achieve it with most of the cars i build.

JRitt@essex

It's not realistic, as you're making presumptions with little to no information. You're looking at a snapshot of a car in a single moment. You have no idea what conditions that car is under at that given moment. Did it complete just one lap? Is it on the tail-end of a 2 hour stint? Is it coming through a section of track in which there are 4 heavy stops back-to-back? Did the driver just apply the brakes at the beginning of a stop from 200mph, or is he at 50mph after slowing from 200mph? All of those items matter if you're going to look at a disc and determine why it's looking the way it looks at any given moment. The look of the disc is perpetually changing, and it's impossible to make conclusions about the caliper and disc design without any actual info or frame of reference. A single snapshot doesn't tell the story.

Below is a video of our dyno in action. Start watching at 1:48 into the vid. On the first brake event in that timeframe, the red bands are narrow. You can see the glowing bands change and grow as the disc becomes more and more heat soaked. There's definitely nothing wrong with the design of the caliper or disc. The calipers and discs on our dyno are the same ones that have won the NASCAR Sprint Cup championship 7 of the past 8 years. They likely have millions of miles of development on them across all teams, hundreds of wins, and lord knows how many podiums. So even if they don't emit the perfect uniform glow on the first brake application, they're obviously capable of getting the job done under the worst conditions. To say or imply that they are not 'well developed' is plain silly.

johnny c

Jeff, we got our fare shake at championships too. hell if the photo of the DP in question was from daytona 24 in 2015, 2013, 2012, 2011, 2008, 2007, 2006 then we won that race




and yes it's fully reasonable expectation that there is no "banding". it's a fully reasonable expectation. i wish i had a video from a customer at the 2012 SCCa runoofs in his prototype. he had a full carbon kit and it developed and dissipated heat perfectly. too bad that video is locked in the archives.

c5racr1

So what's the deal with all these brake parts? For sale, for envying?

GSpeed

Can you tell me bias in that pic too? Maybe corner balance and tire pressure too.