ACR CCBs - How have they performed after 5 track days?

[VENOM V]

Hi all,

Prepare yourselves- this post may go against conventional wisdom and rub you the wrong way

The hardest decision when ordering my ACR was whether to go with steel or carbon ceramic brakes, because of the widely varying opinions on the subject. After three years of tracking my 2013 GTS, I had pretty much outgrown the 4-piston steel brakes. I was in the process of trying to fab cooling ducts for the front brakes, after one shop gave up. Even with TA rotors and Carbotech track pads, my front pads were less than 1/2 thickness after just one day at Buttonwillow. Stock pads of course were much worse- I went all the way to the backing plate on the third session at Laguna Seca. So it was either go for a 6-piston big brake steel kit, or try the CCBs on the ACR Extreme. I chose the CCBs, with the back-up plan of converting to steel if I didn't like them. So how did they perform and hold up?

Break-in: Make sure you burnish these brakes per the ACR manual or they will wear out prematurely. I followed the procedure. Hard to find a place to brake from 90mph-20mph a bunch of times unless you are at the race track, haha.

Performance: All I can say is, wow. First time I tracked the ACR Extreme at Laguna Seca, I was utterly blown away at how much later I could brake before turn 2 (downhill hairpin, breaking at between 135 and 140mph). The lap times spoke for themselves. I ran a number of low 1:34s with a best of 1:34.1. I am still trying to find the limits of the ACR, I believe I can improve on that time. If I attempted to brake that hard and late at Laguna Seca with the steel brakes of my GTS, I would have overheated the pads within 3 or 4 laps. The lap times have a lot to do with the ability to brake late and hard, lap after lap without issue. CCBs FTW. I can't imagine going back to steel for this reason alone.

http://driveviper.com/forums/threads...he-Extreme-ACR

Pad Longevity: New pads are 10mm thick in the front, and 9mm in the rear. After 4 hard track days- 1 at Laguna Seca, 2 at Chuckwalla and 1 at Sonoma- front brakes were down to 4-6mm, and rears were down to 6-7mm. I replaced the front pads and burnished them before going to my 5th day at Thunderhill, but left the rears alone. Two things struck me. The first, that these pads were lasting 4 times longer than my track pads on steel rotors. Second, that the rears were wearing out faster than I expected. This was a surprise, as with my GTS the rears last 3-4 front sets. The culprit may be that I was running the ACR in Track Mode, whereas I tracked the GTS with stability control Full Off. On many cars such as the C7 Corvettes, you can wear out your rear brake pads in one day due to stability control using them often. On my 5th track day, I ran with it Full Off and found the car handles more to my liking. If the car steps out, I can drive through it and it behaves predictably. No drama, just a fantastic car at the limit. Rears have barely worn in that day, fronts are looking good.

Rotor longevity: My biggest concern was not pad life, but rotor life. The pads are fairly reasonable in price, more on that later. The rotors however, are pricey. After talking with one of the SRT engineers, I learned that the rotors last a very very long time (leaving that vague on purpose). The engineers chose a pad compound that is rotor-friendly, so they don't eat CCB rotors like some of the early CCBs on other makes. I spoke with a local hot shoe and mechanic that runs a C7 Z06. He said that they are converting many of their most serious track rats' cars to CCBs that originally had steel. He raved about them, and said his rotors last pretty much forever as well.

IMG_1353 by solomontodd 4mm brake pad thickness gage

IMG_1354 by solomontodd New Vs. Old Pads

Cost comparison to steel: So far, one set of front pads. I won't disclose the price but I got them for MUCH less than list price. And the rotors- I got quotes on them as well. MUCH less than list price. Less expensive than Porsche CCBs rotors/pads, about the same price as ZR1/Z06 CCB rotors/pads on eBay. My front pads are about twice as expensive as the Carbotechs I ran previously, but last 4 times as long. And with iron rotors, I periodically had to deal with uneven pad build-up. At times I turned my rotors, but a couple times I had to replace my front rotors because they got hard spots under the pad build up and were not able to be turned. At this point, I believe total cost to run CCBs will be less than steel. Proof will be when I finally do need to replace rotors, then I will know for sure.

Road and Track: This part is huge. With the GTS, I had two sets of brakes- TA rotors and Carbotech pads for the track, and Stoptech rotors and stock pads for the street. I would swap between them before and after every track event. Talk about a time-consuming pain in the ass! But with the CCBs, they work well everywhere. No loud squealing on the street, no issues with cold stops, no pad build-up, they perform uniformly well hot or cold. And get this- almost no dust! Wheels stay clean and nice a lot longer.

It should be said that steel rotors will be fine for most anyone until they become advanced drivers and are turning fast lap times. Initially my stock brakes were more than adequate, but now I needed something more.

Much of the above was not true of CCBs just a few years ago, but this latest generation is a home run. So far, they win over steel on all fronts- performance clearly, longevity, road and track compatibility, and I think that they will be more cost effective. Brakes are like religion, and I don't want to talk anyone out of their preference. However after fighting with brakes on every other track car, this is a huge advancement to me. Aint never going back to steel brakes.

[CLS]

Great info, thanks.

[Dfunk]

Great write up! I to noticed the low dust. I drove mine 1100 miles home after taking delivery and was very surprised by how clean the wheels were.

[Bruce H.]

Excellent review!

[dkarg]

Very good info, thanks a lot.

[sharmut]

Hi all,
IMG_1353 by solomontodd

That yellow piece next to the rotor appears to be something that prevents debris from entering the calipers, is that a factory item?

[VENOM V]

That yellow piece next to the rotor appears to be something that prevents debris from entering the calipers, is that a factory item?

That's a brake pad thickness gage that was in my hand, 4mm. I should have explained

[Jabba954]

To you point about no squealing - this is because you properly burnished them. If you'd just gone out and done a track day without burnishing, they'd be squeaking like mad now...

[FLATOUT]

Great thread! Thanks for posting.

[ViperJon]

And if I may add another benefit, how great is it to take a 100 mile ride and there is zero brake dust. ZERO.
These are definitely not your daddy's CCB's.

[greygt3]

This is the 5th car I've owned with ceramics and all of them have been great. The ACR brakes are the best yet. Can't even imagine better brakes than these, crazy good!

[ACR Steve]

Great write up ........... Care to share where we can buy the pads for a decent price PM me if you want

Tracking my car for the first time Monday cant wait

Thanks

[Andi]

Do we know yet if these are the same rotors and pads that GM specs for the ZR1 & Z07?

[ViperPete]

That was a great read!

Thanks for the writeup

[VENOM V]

Do we know yet if these are the same rotors and pads that GM specs for the ZR1 & Z07?

They are not the same, not the same compound either. Supposedly they will fit. However in my opinion, no reason to get the Vette pads and mess with success unless ACR pads are unavailable. Pricing is close enough if you shop around. If it works and works well, don't fix it.

I've ordered them three times from three different vendors, everyone has had them in stock so far. My dealer keeps them in stock. The main thing is to get them in advance to when you need them so you don't get caught with your pants down

[Racingbrake]

This is a great evaluation in favor on CCM brake (vs. conventional iron brakes) evidenced by track experience which interests me the most. In rennlist (Porsche) forum you typically see Porsche owners ordered pccb option but put them on shelf and replace them with iron brakes.

So it's a community that's not easy to change their mind, although it could well be due to the prior knowledge of improper set up on earlier pccb (rotor and pad were too small), and the rotor material was not so good comparing to the modern set up today, so we offer both (pccb replacement and iron conversion) for their choice.

Here is one of our typical replies:
http://rennlist.com/forums/gt4/91373...l#post12952845

Either pccb or iron brake has it's own ground / merits from each individual's prospective, and the debate/argument will never end even after hundreds of threads were discussed.

The good news is RacingBrake (RB) has a solution for you; no matter what you have now, or intend to make a brake swap (pccb to iron or iron to pccb) in the future.

If you have pccb (yellow calipers), RB has iron rotor replacement.

http://www.racingbrake.com/RB-Iron-R...por-irk-03.htm
Iron rotors are made with our patented designs (center mount and open slots) with a casting know how accumulated in our 30 years' experience in brake business.

If you have standard brake (red caliper), RB has CCM rotors upgrade:

http://www.racingbrake.com/RB-CCM-Ro...por-crk-07.htm
CCM rotors are made by Surface Transforms with RB design, rotor hat and hardware.

Replacement rotors are made for direct swap without requiring any modification.

We have recently released a series of standard RB-CCM brake kits; Using ZR1/Z28's 394/390 CCM discs and pads with RB 6/4 calipers for 991/997/996/993 so a testimonial like this may help them to consider in deciding for such a change.

Complete RB CCM Brake Kit for 991 GT3
http://rennlist.com/forums/991-gt3-g...r-991-gt3.html

Warren-RB