floating rotors

[ShadowBolt]

I have wanted to change to floating rotors for awhile now but could not make myself pay $550.00 per side. Michael and Marshall have over two years on their Stoptech's. Al told me he had two years on his 12.19" Wilwood set-up before he forgot to put in new pads prior to a race (he thought he had) and tore his rotors up with metal to metal contact. To get set-up for two piece rotors Stoptech wants about $550.00 per side. The best I can find for the Wilwood set-up (rotors and hats less the hardware) is about $340.00 for 12.88" rotors (or if you can use the 12.19" like Al runs) the price goes down to $280.00 per side. After you purchase the complete set-up you are only looking at $170.00 per side for the Wilwood 12.88" race rotors rings or $110.00 per side if you can go with the 12.19" size. These are all 1.25" thick rotors and you would have to have an after market caliper (like Sam and I have) to run them. I talked to several brake engineers and I'm told the thicker rotor holds up better and the floating rotor helps some even when thinner (like the stock Mustang is 1.100") rotors are used. Running the thicker rotor and having it also be floating is what will give you the life several of the guys in CMC are seeing (Dan, Michael, Marshall, and Al to name a few) . I know Adam ran a two piece rotor with the Cobra calipers and he did not get the life these guys are seeing but I don't know if he was using the correct floating hardware to connect rotor and hat. Maybe Adam will respond. I had a two piece setup on my Lighting years ago but I used regular bolts and nuts and did not really have a true floating system (I did not understand the system). They did not last any better than a regular solid rotor.

I talked to AJ at PST about getting us a price for a Performance Friction set-up with smooth rotors. AJ says the two piece PF rotor has some advantages. Most NASCAR teams run PF systems (or at least I know they used to). I found PF kits for a Mustang for $330.00 per side but they have dempled rotors (so no soap). If AJ can get me a PF set-up for around the $330.00 mark and I can not worry about rotors breaking for two years at a time (and even then just replacing the rings) I'm going to go for it.

If any of you is interested in a floating rotor set-up please get with AJ. The more of us that want them the lower the price will be.


JJ

[GlennCMC70]

Anyone can buy, build or make there own 2 piece set-up. The key is in the quality of disc used (rings). The rings can be had from $30 each al the way past $500 each. You need to find the price point your happy w/ (failure rate vs cost per replacement). PF and some others use proprietary bolt patterns (as there are many patterns) for the ring to center hub attachment. So there is no telling what type of disc Adam was using.
So be aware that buying their 2 piece set-ups will lock you into buying rings from them only. Right now, the StopTech guys can only buy rings from StopTech. Likely not an issue as long as the disc's are available and not $500 each.
Also - PF uses a steel center hub for the OEM replacement designed rotors. I looked into this when I was looking to up my rotor size to 13" and stay w/ the OEM caliper. That turned me off at the time cause I was already having weight issues w/ the car. I also wasn’t ready to be locked into 17" wheels just yet.

Dimples....... At this point I don't see why we don't allow slots and dimples. Not sure on the holes, but I can't see any issues. Kinda dumb to allow a brake upgrade like we have and require a smooth disc. It is like saying we can't run ARP studs unless they have the unthreaded alignment tip at the end like OEM. This should have an RCR submitted for it at the end of the year.

[ShadowBolt]

Anyone can buy, build or make there own 2 piece set-up. The key is in the quality of disc used (rings). The rings can be had from $30 each al the way past $500 each. You need to find the price point your happy w/ (failure rate vs cost per replacement). PF and some others use proprietary bolt patterns (as there are many patterns) for the ring to center hub attachment. So there is no telling what type of disc Adam was using.
So be aware that buying their 2 piece set-ups will lock you into buying rings from them only. Right now, the StopTech guys can only buy rings from StopTech. Likely not an issue as long as the disc's are available and not $500 each.
Also - PF uses a steel center hub for the OEM replacement designed rotors. I looked into this when I was looking to up my rotor size to 13" and stay w/ the OEM caliper. That turned me off at the time cause I was already having weight issues w/ the car. I also wasn’t ready to be locked into 17" wheels just yet.

Dimples....... At this point I don't see why we don't allow slots and dimples. Not sure on the holes, but I can't see any issues. Kinda dumb to allow a brake upgrade like we have and require a smooth disc. It is like saying we can't run ARP studs unless they have the unthreaded alignment tip at the end like OEM. This should have an RCR submitted for it at the end of the year.

I agree that not all rotor rings are equal. Wilwood sells many different types and the money goes up as the quality does (or should). I'm impressed Al got two years out of the 12.19" rotors but I can't use them with the caliper kit I purchased from Don (it's made for a 13" rotor). I may end up with Wilwood just becase of how easy the new rings would be to get. If we could run dimples I would order a set of PF today for $330.00 each and keep my old stock rotors for a back-up since I can run either with my set-up.

JJ

[michaelmosty]

I know the big brake kits are a heated discussion point but I am very glad I bought them. Performance aside, over 2+ years I have saved probablly $500 in rotors and just a small amount in brake pads. The pads usually last 5 events vs. 3 events but are more expensive.
Just the idea of not having to check pads and rotors for spreading calipers / cracked rotors is great!!
If you can get a good set of 12.88" rotors that have the same life as the StopTech ones then you'll be in business.

I agree the dimple/slotting is a silly rule. I am not an engineer but I can't see the performance advantage, only a cost savings.

[MikeP99Z]

I am not an engineer but I ..slept at a Holiday Inn Express last night?

My first set of Stoptech rotors lasted almost 4 seasons (around 20 event weekends). The second set I put on in mid-2010 is still looking good (granted, they only have 6 events on them since then). As i recall, they are $250/ring. I've run a variety of pad compounds. My front pads typically last 2 weekends.

[Rsmith350]

Hahahaha!!!!,

[BlueFirePony]

Input for the sake of an extra data point.
I used a set of DBA 2 piece rotors (slotted and drilled) on the front from 2007-2011 right before Hallet. Got them for $500 together in 2007 - the new 5000s cost $800 a set most places. I did switch them out from time to time to test different rotors but all NASA weekends and any DEs Kyri ran himself (4 or so?) including the back-to-backs Kyri and I ran were on the DBAs.
Doing pre-weekend inspection before Hallet in 2011 we found some small cracks on most of the dimples on one front rotor and a few cracks on the other front rotor and also at that time found a sizable crack on one of the stock rear rotors so I changed out all four corners.

Until then the only issue I had was the dimples kept getting blocked with dust if my brake ducts shifted (which they tended to do...new design in the works).
New set seemed great and lasted Hallet, TWS and about 4 hours at ECR - damn brake pads :(
Got 3 weekends on most sets of pads until ECR....got around 11 laps on that set <shrug>

[RichardP]

I talked to several brake engineers and I'm told the thicker rotor holds up better and the floating rotor helps some even when thinner (like the stock Mustang is 1.100") rotors are used. Running the thicker rotor and having it also be floating is what will give you the life several of the guys in CMC are seeing (Dan, Michael, Marshall, and Al to name a few).

The key is in the quality of disc used (rings).

Thicker/heavier rings and the quality of the materials/manufacturing of the rings are the primary factors in rotor life. A floating setup has something to do with it but I believe it to be a secondary effect.




I know Adam ran a two piece rotor with the Cobra calipers and he did not get the life these guys are seeing but I don't know if he was using the correct floating hardware to connect rotor and hat.

Adam was using Coleman Racing rotors on TCE hats. It allowed him to use 12” rotors with Cobra calipers under 16” wheels (max CMC legal at the time). He had the slimmer Cobra rotor thickness and the rotors were fixed. A floating rotor setup wasn’t warranted because he was still using a floating caliper. He didn’t get spectacular rotor life but I didn’t think it was too bad. The reality is that the max CMC allowed brake setup at that point wasn’t the significant over kill that the currently allowed brake setups are.




So be aware that buying their 2 piece set-ups will lock you into buying rings from them only. Right now, the StopTech guys can only buy rings from StopTech. Likely not an issue as long as the disc's are available and not $500 each.

That’s not quite true. Coleman has several different rotor blanks that they can machine to whatever diameter/thickness/bolt pattern you want. The cool thing about the Coleman stuff is that the rotors are available in different weights. If you wanted to spend money on a CMC legal performance benefit, you could use the heavy Stop Tech rotors for hard braking tracks like Hallett or Eagles and swap on a much lighter rotor for tracks that aren’t too hard on brakes.




Dimples....... At this point I don't see why we don't allow slots and dimples.

Oh no. More rules creep. It will start with dimples. Then someone will step it up with an engraved bear claw or teddy bears. Next thing you know, people will think they can’t be competitive without their car number or that naked lady you see on mud flaps engraved into their rotors. Where will it stop? It’s just like allowing an extra stitch weld here or there is a clear step towards full tube frame cars…

Actually, I welcome allowing some sort of pattern on the rotor surfaces. Since Dan has CNC mills, I fired up Pro-E and came up with a trick pattern to machine on the inside rotor surface that will propel the car forward when the air from the brake duct is blown on it. And this is power that won’t show up on the dyno when the front wheels are static. I had to make some assumptions on flow, restrictions, efficiencies, etc. but doing the math, along with some computational fluid flow modeling, I found that this could be a real benefit. Granted, I need to refine my analysis a bit. Doing some energy in/energy out balance equations I’ve apparently created a perpetual motion machine which is possibly not realistic. But I’m pretty sure I’ve come up with a can’t lose setup. I just need the rules makers to allow it…


Richard P.

[ShadowBolt]

Thicker/heavier rings and the quality of the materials/manufacturing of the rings are the primary factors in rotor life. A floating setup has something to do with it but I believe it to be a secondary effect.
Richard,







Adam was using Coleman Racing rotors on TCE hats. It allowed him to use 12” rotors with Cobra calipers under 16” wheels (max CMC legal at the time). He had the slimmer Cobra rotor thickness and the rotors were fixed. A floating rotor setup wasn’t warranted because he was still using a floating caliper. He didn’t get spectacular rotor life but I didn’t think it was too bad. The reality is that the max CMC allowed brake setup at that point wasn’t the significant over kill that the currently allowed brake setups are.





That’s not quite true. Coleman has several different rotor blanks that they can machine to whatever diameter/thickness/bolt pattern you want. The cool thing about the Coleman stuff is that the rotors are available in different weights. If you wanted to spend money on a CMC legal performance benefit, you could use the heavy Stop Tech rotors for hard braking tracks like Hallett or Eagles and swap on a much lighter rotor for tracks that aren’t too hard on brakes.





Oh no. More rules creep. It will start with dimples. Then someone will step it up with an engraved bear claw or teddy bears. Next thing you know, people will think they can’t be competitive without their car number or that naked lady you see on mud flaps engraved into their rotors. Where will it stop? It’s just like allowing an extra stitch weld here or there is a clear step towards full tube frame cars…

Actually, I welcome allowing some sort of pattern on the rotor surfaces. Since Dan has CNC mills, I fired up Pro-E and came up with a trick pattern to machine on the inside rotor surface that will propel the car forward when the air from the brake duct is blown on it. And this is power that won’t show up on the dyno when the front wheels are static. I had to make some assumptions on flow, restrictions, efficiencies, etc. but doing the math, along with some computational fluid flow modeling, I found that this could be a real benefit. Granted, I need to refine my analysis a bit. Doing some energy in/energy out balance equations I’ve apparently created a perpetual motion machine which is possibly not realistic. But I’m pretty sure I’ve come up with a can’t lose setup. I just need the rules makers to allow it…


Richard P.

The brake guys said the thicker rotor would hold up better but the floating rotor shoud not crack all the way through as easy since it can grow and shrink with less stress on it than a stock type one piece rotor. I usually have three or four rotors brake all the way through during cooldown per season. When I ran the TCE set-up on the Lightning I used bolts and nuts and tightened it all up so it could not contract and expand like the good floating rotor hardware does. Either way I'm trying to get what Dan and Michael have (rotor life wise) for half the money.

JJ

[GlennCMC70]

Thanks Richard - I didn't know Coleman did that w/ the rings. Good to know.

[AI#97]

Thanks Richard - I didn't know Coleman did that w/ the rings. Good to know.

Racingbrake.com also sells the 13" stoptech rings for $412/pr....however, they have slots, unsure if you can order plain.

Only thing I can offer about the coleman stuff is the experience I had with them. They are too light. If you go too light there isn't enough heat sink capacity...remember my glowing rotors from Miller! The coleman rotors are also a much lower grade materials than what comes with the stoptech kits. Keep in mind that Coleman usually requires 7-10 days at a minimum to cut rings for you. Zeckhausen and others keep stoptech rings in stock. Brembo rings are also same dimensions and bolt pattern as stoptech...and some Alcon kits use the same rotors as stoptech.

Point of interest on my car....I used to run the 13"x1.1" coleman 2pc setup and the rings weighed 11.2 lbs each. I had to run EVERY bit of ducting I could to keep them cool even running SRF fluid. I switched to my custom Alcon/Stoptech setup in 14"x1.25" that weigh 14.2lbs each....I no longer run brake ducts but haven't been to hallett or other brake eating tracks and have switched back to ATE fluid saving a lot of money.

Jerry, my advice is to call david donovan and order the stoptech hats and rings (not slotted) and don't look back. the PFC stuff is nice but it's DAMN hard to get quickly if needed and it's friggin' expensive. It's really nice stuff but not needed. You may have to make a new caliper bracket or shim it, but you will be dollars and availability ahead. The wilwood stuff isn't bad as you can get it at Jegs/summit, but after seeing misty's kit she had on the camaro, the walls of the rotors were too damn thin and couldn't hold heat.

[ShadowBolt]

Racingbrake.com also sells the 13" stoptech rings for $412/pr....however, they have slots, unsure if you can order plain.

Only thing I can offer about the coleman stuff is the experience I had with them. They are too light. If you go too light there isn't enough heat sink capacity...remember my glowing rotors from Miller! The coleman rotors are also a much lower grade materials than what comes with the stoptech kits. Keep in mind that Coleman usually requires 7-10 days at a minimum to cut rings for you. Zeckhausen and others keep stoptech rings in stock. Brembo rings are also same dimensions and bolt pattern as stoptech...and some Alcon kits use the same rotors as stoptech.

Point of interest on my car....I used to run the 13"x1.1" coleman 2pc setup and the rings weighed 11.2 lbs each. I had to run EVERY bit of ducting I could to keep them cool even running SRF fluid. I switched to my custom Alcon/Stoptech setup in 14"x1.25" that weigh 14.2lbs each....I no longer run brake ducts but haven't been to hallett or other brake eating tracks and have switched back to ATE fluid saving a lot of money.

Jerry, my advice is to call david donovan and order the stoptech hats and rings (not slotted) and don't look back. the PFC stuff is nice but it's DAMN hard to get quickly if needed and it's friggin' expensive. It's really nice stuff but not needed. You may have to make a new caliper bracket or shim it, but you will be dollars and availability ahead. The wilwood stuff isn't bad as you can get it at Jegs/summit, but after seeing misty's kit she had on the camaro, the walls of the rotors were too damn thin and couldn't hold heat.

PF is $330.00 Stoptech $550.00. Al got two years out of the Wilwood set-up and was only running 12.19" rotors. I may regret it but I'm not spending the money for the Stoptechs. $650.00 is bad enough but I'm not spending $1100.00. Wilwood mades a lot of different grade rotor rings. I don't know if there best is even clost to Stoptech pr PF.

JJ

[RichardP]

Only thing I can offer about the coleman stuff is the experience I had with them. They are too light. If you go too light there isn't enough heat sink capacity...remember my glowing rotors from Miller! The coleman rotors are also a much lower grade materials than what comes with the stoptech kits. Keep in mind that Coleman usually requires 7-10 days at a minimum to cut rings for you.
Point of interest on my car....I used to run the 13"x1.1" coleman 2pc setup and the rings weighed 11.2 lbs each. I had to run EVERY bit of ducting I could to keep them cool even running SRF fluid. I switched to my custom Alcon/Stoptech setup in 14"x1.25" that weigh 14.2lbs each....I no longer run brake ducts but haven't been to hallett or other brake eating tracks and have switched back to ATE fluid saving a lot of money.


OK, did you really just say that the Coleman stuff is too light and made out of crappy material because your 13 x 1.1” – 11.2# rotors didn’t hold up as well at Hallett, even with brake ducts and fancy fluid, as do your 14 x 1.25” – 14.2# rotors at say TWS???

I will say that a 13 x 1.1” setup would easily be considered insufficient on a hard run AI car on a heavy braking track, regardless of what name is on the parts. It’s equally reasonable to say that a 14 x 1.25” setup would likely be sufficient on an AI car for most tracks.

The real question is whether the 14 x 1.25” Stop Tech rotors on your car are better than equivalent Coleman rotors in the same size? I don’t have the answer to that question. Based on my experience with Stop Tech, I wouldn’t bother trying the Coleman rotors. I’m glad Jerry is planning on trying the PF rotors. I want to see how they do. If it was my money, I wouldn’t risk it just to save a couple bucks.

As far as shipping time, it’s my direct experience that Coleman will have a completely custom rotor machined to your specs at your door quicker than Stop Tech can have a blank, non dimpled ring to you.


Saying the Coleman rotors are too light is just absurd. They make anything from a ¼” thick non-vented rotor to a 16” x 1.5” rotor or, if you are limited to a realistic wheel diameter and need even more thickness, a 13.5” x 1.625” rotor. More relevant to the thread, in the nominal 13 x 1.25” CMC legal size they have options of internal air gap widths of .625”, .650”, or .720”. The smaller the internal air gap, the thicker the walls of the rotor are and the heavier it ends up being. For those that like to push things to limits, the CMC rules actually state a rotor size of 13.1” x 1.31”. You can get a Coleman rotor to exactly those sizes and the increased wall thickness will give you more weight, heat capability, and rotor life.

If your goal is to have a rotor that lasts through five years of hard racing and absolutely cannot fade no matter what you do to it, that is fine. Just be aware that you will pay a small performance penalty for that extra weight every time you accelerate or hit a bump.

Richard P.

[Rsmith350]

Anyone with the c5 brake upgrade found good rotors to use? Would Stoptech make ones that would fit?

[RichardP]

Anyone with the c5 brake upgrade found good rotors to use? Would Stoptech make ones that would fit?

StopTech doesn't make anything that doesn't specifically fit with their brake kits. It probably wouldn't take much to make a caliper mount for a C5 caliper to grab a StopTech rotor, though.


Richard P.