mikymu

Back in 2009 I did a post about converting my 2007 Porsche GT3 RS ceramic rotors to GT3 Cup steel rotors - http://forums.rennlist.com/rennforum...onversion.html - because Porsche ceramic rotors did not stop my RS well on the track despite using the most aggressive Pagid motorsports racing pads.

When I was shopping for a Z06 carbon edition I was intrigue again by the ginormous brembo ceramic composite rotors that are basically the same one fitted on Ferrari 430 and 458 Challenge. I decided to give it another try. Here is video describing how these ceramic rotors are made ... trust me, with track use, ceramic does not last 60X longer than steel rotor as the video indicated lol



So, if it works on Ferrari challenge then it should be much better than the one found on my 7.1 GT3 RS right .... well, not really. After driving my Z06 hard for the past 1.5 years this is what I found out:

Street driving: brake really well and much improved initial bite than my 7.1 GT3 RS ceramic rotors. It's super quite and overall very happy with it. Replacement rotors are about $1400 each if you shop around which is a knock out bargain compare with what Porsche and Ferrari charge. Replacement OEM pads are still very expensive - about $1K a set made by textar which is basically a "mild" pagid brake pad



Track use: Again it is much improved from my 7.1 GT3 RS ceramic rotors. Instead of feeling like I am going to blow through the brake zone every time there are actually some decent bite - still not great. When I come to a high speed brake zone there are few milliseconds of absolutely nothing when I step on the brake then all of a sudden you feel the brake bite but still not enough then you REALLY have to apply tremendous amount of brake force to slow down the car and once you let go of the brake there are not much modulation as steel rotors.

I was not happy with my Z06 ceramic rotors but not horribly bad like the Porsche ceramic rotors so I decide to stick with it. Every brake zone with the Z06 is an adventure and one thing I noticed is that when you have two brake zones back to back in a short distance the brake pedal become solid HARD!? You had to literally stand on the brakes for the car to slow down - perfect example is between T10-T11 at Thunderhill. I always make sure to keep healthy distance when I approach another car through this section of the track just in case if I can't stop in time.

After mucking with OEM pads for 7-8 track events I had enough and decided to try endless ME20 compounds. It brake slightly better but all the flaws remains.

I decided to switch to some sort of steel rotors after I almost lost the car coming into high speed braking zone at Thunderhill - when I mistakenly try to modulate the brakes as if it was steel rotors and the car just barrel ahead. The perfect analogy to describe ceramic rotors on the track is like trying to operate a defective ON/Off light switch. You had to toggle the switch back and fourth hard then it will turn on where as steel rotors are like a dimmer switch. You can modulate the brakes and control it with brake pedal force. Imagine your basketball shoes behave like ceramic rotors - you will be sliding all over the court and worst fumble your dribble and fall flat on your face when your shoes make you stop abruptly and let go without warning

OK, after much research comparing cost and rotor material I decided to try RB performance brakes . Warren from RB was very helpful in explaining their two piece rotors manufacture process which include heat treated iron rotors that are suited for track use with unique bolt pattern that ensure even distribution of force on both sides of the rotors back by warranty - I have seen some other after market manufacturer not backing their product when their rotors crack with track use.

Here are some description of their unique two piece rotor technology ... I like anything with technology
http://www.racingbrake.com/v/main/technology.asp


The conversion was just fantastic! It was easy to swap the rotors and everything fit like OEM and OMG ... I actually got real brake modulation back again as demonstrated by video below

I use the same endless ME20 brake pads ( with very little pad material left) so I get a clear comparison and the only variable is the rotor material. I feel brake bite the very moment my foot touch the brake pedal and I can modulate the brakes and the brake pedal remain responsive even between short brake zones like T10-T11 at Thunderhill.

Conclusion: Ceramic composite rotors is a great technology and we can all use less rotational mass for better performance. Where it stand now the technology is OK for street use but it still has alot of catch up to do for track use. The cost is coming down but not to the point that we can use crazy abrasive brake pads like F1 or prototype to achieve adequate brake modulation



Here is a detail DIY for reference

Massive OEM brembo 394 mm front and 380 rear ceramic rotors





RB two piece open slot iron rotors



front side





back side





quick check on the attachment bolts and every single one is securely torque from factory



Couple close up shots of their unique design and bolt pattern





you need to remove the brake calipers by first remove the retaining pins - just tap them out





pretty worn out front endless ME20 brake pads and did not last much longer than OEM - these have about 7-8 track events





compare with OEM with same amount of track use





removal of the two large caliper bolts - I think they were 21mm and thread lock on the bolts from factory really made it hard!





torque spec - 129 lb ft! to secure the bolts



off goes the caliper and make sure to support it



front rotors side by side comparison - RB steel rotors is 390x36mm compare with OEM 394x36mm





back side



ceramic rotor weigh 5880g (12.96 lbs) which exceed the minimum weigh etch on the hat - 5830g



vs RB steel rotor 28.05 lbs - 15 lbs weight gain ... it's worth it



Thickness is also good and exceed minimum thickness



clean up the wheel hub to receive the RB steel rotor and install the caliper



perfect fit





we got real brakes!!



Now the rear rotors - pretty much the same procedure as front - same large 21mm bolts secure brake caliper that calls for 129 lb ft to tighten the bolts





rear brake pads are still pretty thick





much like OEM after about 7-8 track events





rear wheel hub with parking brake pads



rear rotors have the same same diameter 380 mm but steel rotor is 2 mm thinner - 32 vs 34 mm





rear ceramic rotor weigh 7325g (16.15 lbs) which is way above minimum weigh



vs RB steel rear rotor 22.09 lbs - about 6 lbs weight gain.



you have to reduce the rear parking brake pads diameter to fit the RB steel rotor by rotating the brake pad adjuster - you may need to press down on the spring retainer at the teeth to make rotating the adjuster easier





install RB rotor and brake caliper





All set front and back - now we got functional rotors that will deliver on the track!



Confidence at the braking zones is priceless - especially short brake zones between T10-T11 at Thunderhill shown below

with practice I will be able to properly modulate the brakes and gain valuable time at each brake zones

mirage2991

still expensive as hell... compared to what they offer for the z06... I suppose it is an cheaper alternative for track cars since replacement rings are (still) 475 a pop. I am quite intrigued by your issues with the ccb rotors though as others have no problems and have recorded more track time with ccb than steal before having to replace them.
I know over the P camps track guys have switched to iron rotors from their ccb due to the outrageous cost of those rotors (20k for 4 i think ?). I also know racing teams are not using ccb but I think it is because of regulations (?).
So perhaps ccb will only become a street car thing...Now you got me wondering, thanks to you I need to go do research on that... thanks alot! lol j/k
good write up too!

mirage2991

by the way, what type of brake fluid are you running and what if any extra cooling of the ccb brakes have you tried? ccb do not absorb as much heat so it all get transfered through the pad to the caliper... perhaps you were having a cooling issue?

mikymu

I use Motul brake fluid and works well. Stock ZR1 cooling is very good. You need alot of heat for these ceramic rotors to generate necessary brake torque. As it stand now, these ceramic rotors are only good for street use

racerns

I think there are a few guys on here that will disagree with you on that, as they have been very sucessful tracking the stock rotors. I am sure they will chime in soon. I have only done a few events up to this point so my experience is somewhat limited but I have had no issues thus far.

mikymu

Yes, that is true ... to an extend. It all depends on what is acceptable for the driver. I am speaking from my personal experience driving near race speed. People may be happy with lack of modulation (many don't truly appreciate what good brake modulation feel like) and make up the time loss at brake zone with horse power. I see that alot here where ZR1 blast through the straight then crawl through braking zones.

There are Porsche owners that are very happy with their ceramic rotors with occasional track use but they are not fast drivers. All the fast GT3 guys switch to steel rotors for better brake modulation

The fact that I stay with the ceramic rotors for more than a year speak to the improvement of these rotors compare with my GT3 ceramic rotors but it's still no where close to the proper brake performance and modulation delivery by steel rotors

This is a video of my recent outing with ceramic rotors. You can hear the tires squeal with ABS kicking in at brake zones because I had poor brake modulation and need to apply constant hard brake pressure to stop the car - which is not good for lap times

racerns

Some of the guys I am talking about are very fast drivers and do compete time trials. QUIKAG is running his car in TT1 and has been able to come very close to the track record for that class. I have not heard him complain about modulation issues. It could also be track dependent.

While my ZR1 track experience is limited to a few track days I have been doing open tracking, time trials, and instructing for many years. I plan on doing many more track days and time trial events next year with the ZR1 so I will be on the lookout for the issue you have described.

mikymu

sounds good.

our ZR1/Z06 can put down some impressive laps if driven well as you have mentioned. It all comes down to driver preference when we talk about brakes. I like to be able to modulate the brake force instead of the on/off characteristic of the ceramic. It's always a shock driving my Z06 after coming off driving my GT3 Cup or civic racer with steel rotors.

K B Vettin

great write u, thansk for the info i'm doing my second track day in my zr1 next month and will look out for braking issues.

on another note, what size wheels and tires are you running?

mikymu

sure thing

These are 18" foregeline GA3R and I typically run 295/30/18 front and 345/35/18 rear Hoosier R6 size

Lasco001

[QUOTE=mikymu;1585477862]Yes, that is true ... to an extend. It all depends on what is acceptable for the driver. I am speaking from my personal experience driving near race speed. People may be happy with lack of modulation (many don't truly appreciate what good brake modulation feel like) and make up the time loss at brake zone with horse power. I see that alot here where ZR1 blast through the straight then crawl through braking zones.

There are Porsche owners that are very happy with their ceramic rotors with occasional track use but they are not fast drivers. All the fast GT3 guys switch to steel rotors for better brake modulation

The fact that I stay with the ceramic rotors for more than a year speak to the improvement of these rotors compare with my GT3 ceramic rotors but it's still no where close to the proper brake performance and modulation delivery by steel rotors[]

@mikymuRight, I'm exactly the same opinion.
I did that as well already written a couple of times.

Carbon is good for road and comfortable on the track.
For very fast guys steel brake is the best.

Here are two ZR1 with steel brake
The white is my friend and the black I drive itself

@miymu good report

mikymu

[QUOTE=Lasco001;1585479507]Thanks for sharing your video. That look like a really fun track! 172 mph ... WOW

Good to hear you had positive experience with your steel rotors.

vette ruminator

This is all good info. I enjoy tracking my ZR1 about 12 days a year and I have been considering the steel option for some time (mostly due to cost of replacement). I had steel rotors on my 08 ZO6 and still remember good feel with Cobalt pads and steel rotors. Clearly I need more seat time to develop my skills (I may just be one of those guys that isn't fast enough in the corners but tries to make up for it with the go pedal). I have been satisfied with the stock setup as a street/track combo but I have been considering an aftermarket steel setup if it is engineered well enough. I'd be interested to know how your system compares re cost per track day and longevity.

Nice DIY notes. Wish my calipers were as clean as yours!

mikymu

Thanks, these calipers are consider dirty and pretty beat up and have a new set standing by

These steel rotors should last a long long time. I did the switch not so much for cost saving but more for better braking performance. After 1.5 years I am done with the awful on/off feel of the ceramic rotors

oversteer

Excellent write-up. You Sir get a 10 out of 10

If the RB rotors don't crack or wear out after ten track days on your car I will buy a set! Please keep us updated on their durability.

Fretka

Really need to see a brake dyno comparison to quantify the differences. On my Ducati factory race bike I use full floating rotors as opposed to semi floaters on street bikes (mine rattle like hell). Do car brakes do the same?

Brembo found some time ago that individual pads (1 pad per piston) allowed the construction of a much stiffer caliper which made a substantial difference as to both outright braking and modulation. Looking at the calipers you are using makes me think that they would flex substantially giving a sort of non-linear braking as the initial fluid movement needs to force the flex out of the system first.
You say you are using Motul fluid so I assume your boiling point is 625 degrees or more, yes?
Lastly, I wonder if using steel braided hose in place of the stock flex hose would benefit you. I kinda think that a more rigid caliper design would payoff.

Thanx for the write up, very enlightening.

Bruce

Al3x_666

How much for steel rotors ?

mikymu

Thanks

Will update as time go on. I was glad to be able to get one last track session in before wet winter set in

Sure thing Bruce. No issue with caliper flexing and that's with both GT3 cup and Z06. No brake fluid boiling either and I had the same Motul fluid for past 1.5 years.

I decided to stay with rubber hose since I did not notice brake fade. My GT3 Cup use rubber hose and it has great brake feel ... so I stay with rubber end hose with my Z06.

Here you go

http://www.racingbrake.com/ProductDe...ductCode=ZR1-P

Fretka

Something that finally filtered thru my thick skull is that (I assume) most of these cars still use iron calipers. I would tend to think that caliper flex would not be much of an issue then. The small amount of rubber lines in your car would probably not show much diff when switched to rubber/steel braid lines.

I come from performance motorcycle world where these things are mandatory due to use of aluminum calipers and rotor carriers.

So scratch most of what I said above! (I would still like to see individual pads/pistons tho).

chuntington101

milkmu, is there any way to reduce the weight if the iron disks at all? Is there any weight that could be removed from the bell?