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Anybody know anything about european floating rotors as an alternative to the pricey big brake kits by Brembo and Stop Tech for mostly street use? I'm told they are a big improvement over stock for a guy who doesn't track his car much. Where can I get them?
 

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Texas said:
Anybody know anything about european floating rotors as an alternative to the pricey big brake kits by Brembo and Stop Tech for mostly street use? I'm told they are a big improvement over stock for a guy who doesn't track his car much. Where can I get them?
The Euro floating rotors aren't going to "feel" any different or change the way your car brakes. The big advantage to them is that they are about 1.5 pounds lighter per rotor in front and slightly less in back. That's helpful for improving ride and handling. And during severe driving conditions (i.e. track events) the rotor will be less prone to distortion since it can expand in all directions unconstrained. That leads to less tapered pad wear and firmer pedal feel during track conditions. It does nothing on the street at legal speeds.

I think you can get them from EvoSport - another board sponsor.

If you want to improve your pedal feel without buying an expensive big brake kit, you would be better off looking at more agressive pads, such as Axxis Ultimate. Look into changing your brakelines for some stainless braided lines. And make sure you've bled your brakes properly. A good bleed done properly can improve the pedal feel of a brand new car as delivered from the factory. See: http://www.zeckhausen.com/bleeding_brakes.htm
 

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This subject has been discussed at various points in the past. The concensus is, if I recall correctly, that the "Euro" floating front rotors provide only a small heat capacity increase over the stock U.S., one-piece rotors and thus are not the solution for track use. The U.S. rotors, with proper choice of pads, fluid, etc. per Dave Z. instructions, are entirely adequate for street use.

Aftermarket Brembo/StopTech front end BBK is needed for serious track use.

All of the above having been said, I did add the Euro 2-piece rotors in the rear of my car to get a little more heat capacity.

Regards, Dick Roberts
 

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The Euro rotors also have had some issues with causing vibrations and pad deposits if I remember correctly. Many European M5s are now running the US spec one peice rotor as it is more reliable for everyday use.
 

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RRoberts said:
All of the above having been said, I did add the Euro 2-piece rotors in the rear of my car to get a little more heat capacity.
At the risk of sounding picky, let's discuss the "heat capacity" of the Euro floating rotors. If you use the traditional definition of heat capacity, meaning how much heat can it absorb before you run into fade problems, then it actually has LESS heat capacity than the 1-piece American rotors. The aluminum center hub, isolated by 12 steel pins, means the iron friction ring has less mass to hold rhe same amount of thermal energy. Thus, for any given stop, the Euro rotor will be hotter than the American rotor. Bottom line - the American rotor is a bigger heat sink. As far as SHEDDING heat, the two rotors should be very similar.

Now let's take a looser definition of "heat capacity" where it can mean the ability of the Euro rotor to get really really hot and still not have some of the problems that would affect performance on the 1-piece rotor. The fact that the Euro rotor actually floats on those 12 pins, means that it won't distort at high temperature. (This is called coning.) So you end up with a firmer pedal under race conditions since the rotor remains flat.



Unless you also change pads to a higher performance compound and flush your brake fluid with something like Motul 600, the Euro rotors will not help you avoid fluid fade or pad fade. In fact, they may aggravate an existing condition.
 

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I take it by there being less heat transfer (than a solid once piece design) there's also less chance of grease being boiled out of the wheel bearing (leading to its failure) with the floating disc ? or is that even an issue nowadays, its just something my mechanic brought up while lambasting about glowing-red-wheel-disc syndrome :7:
 

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Úbermensch said:
I take it by there being less heat transfer (than a solid once piece design) there's also less chance of grease being boiled out of the wheel bearing (leading to its failure) with the floating disc ? or is that even an issue nowadays, its just something my mechanic brought up while lambasting about glowing-red-wheel-disc syndrome :7:
You are correct. The steel pins isolate the aluminum hat from the iron friction ring, resulting in less heat transfer to the wheel bearings.
 

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Just my 5 cents (euro cents...)

I've had no problems at all, either during track or normal driving with my euro brakes. However, the pads wear out very quickly, but that doesn't have anything to do with the disk, for all I know.

Only thing i've noticed, it that there is some vibration during break-in of new pads, but that goes away after a short peroid. I've used 3 sets of pads, and 1 set of discs this summer, so i've testet it a bit :) (During 7(?) track days)

During one event, we were flagged to a complete stop in the middle of a "race" (stupid organizers) and that didn't hurt my brakes at all, while a lot of people had problems after that stop. (Standing still with red hot brakes are NOT good)

On the same subject, normal pads worked better for me on track than Red and Yellow stuff from EBC (waste of money imo)

Not noticed any conciderable fade either. And the disk has been VERY hot.... (Ever tried using your discs as side lights on your car during night ? :) )

I don't know about the US spec discs, but for normal driving, to moderate track use (using normal tires) I have no problem recomendig original eurospec. For serious trackdriving (with r-rated tires) you need stoptech or similar setup...
 

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My 2 cents. I've had EFRs on the front for about 83,000 miles. Got 87,000 on the car. Used to track at DEs and had both the solid and floating on the car.

Dave is really correct. There is very significantly LESS heat transfer to the hub/tire area. Not measured by gauge, but by my hand. I couldn't touch the wheel/tire before mounting the EFRs. I could put my hand on both after the installation.

That was my main advantage and desire. Never had any fade and on a good day I could routinely run 2.23-2.25 at WGI. Never had warpage or pad build up either. I did drive around on the infield for at least five minutes after a cool down lap, however. That is a real cool down.

They (the fronts) are to the point of replacement now. I have already replaced the solid rears with EFRs though that is really nothing more then for looks. The rears were never an issue before! I'm putting Stainless lines on the front also, when I do the change.
 

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DZeckhausen said:
Now let's take a looser definition of "heat capacity" where it can mean the ability of the Euro rotor to get really really hot and still not have some of the problems that would affect performance on the 1-piece rotor. The fact that the Euro rotor actually floats on those 12 pins, means that it won't distort at high temperature. (This is called coning.) So you end up with a firmer pedal under race conditions since the rotor remains flat. Unless you also change pads to a higher performance compound and flush your brake fluid with something like Motul 600, the Euro rotors will not help you avoid fluid fade or pad fade. In fact, they may aggravate an existing condition.
Dave:

You may recall our past discussions where I found that the Pagid Orange pad on the StopTech front BBK was producing very heavy deposition and fast pad recession under track use (Road America). I was clearly exceeding the max. pad temperature limit of the Pagids. I never have had any brake fluid issues with either Motul 600 or ATE Typ 200 (or Blue) fluids, and run with open cooling ducts (such as they are). Moving to PF01 pads with StopTech titanium heat shields completely eliminated deposition and premature wear issues, and significantly upgraded braking performance. I decided to upgrade the rear as well at this time, going to Porterfield R4 pads and the 2-piece Euro rotors, as I expected the front upgrades would allow lower lap times and maybe produce higher loading in the rear. I had previously had no big issues with the Axxis Ultimate/stock rotors at the rear other than noticeable pad wear rate. The rear upgrades may be overkill, but that's the kind of person I am.

Regards, Dick Roberts
 

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At the risk of sounding picky, let's discuss the "heat capacity" of the Euro floating rotors.
Dave,

After reading your response a few times, I'm still not sure I completely understand it. From your writing, it seems to me the Euro rotor does nothing better other than weigh less, and "feel" better under hard braking conditions. Although it may feel better, it actually doesn't have better stopping/heat shedding abilities. Is this an accurate statement?

Travis
 

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Not to answer for Dave Z., but his answer says:

1. The brake part of the 2 rotor designs is the same, so the braking performance should be expected to be the same (assuming same pads, fluid, etc. The main difference would be less heat transferred to the hub/bearing/wheel, plus it's a little lighter.

2. The pinned rotor disc is completely free to grow in an axial direction, so as it is heated by brake pad friction it will stay flat. By comparison, the U.S. one-piece rotor will try to assume a "dished" shape as the friction surface gets hot and the hub stays a little cooler (due to heat transfer to the wheel and bearing). Thus, if we are talking about ultimate braking performance - with race pads, race fluid, and race tires - the 2-piece design will do a better job of keeping the pads in full contact with the rotor friction surface. The outcome will be somewhat improved ultimate braking performance vs. the stock rotor.

Also implied: aftermarket big brake kits are capable of much better performance than the above given the right pads, fluid, cooling ducts, etc.

Regards, Dick Roberts
 

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RRoberts said:
Not to answer for Dave Z., but his answer says:

1. The brake part ... blah blah blah [stuff deleted]
I couldn't have put it better! Thanks for saving me some typing. :cheers:

It's nice to know this forum runs itself when I'm busy doing a 4-wheel BBK installation! Takes the pressure off. ;)

By the way, if you're juggling the economics of Euro rotors vs a big brake upgrade, I've sweetened things up a bit for the latter. The StopTech 4-wheel big brake kit is $1,000 off for forum members between now and Thanksgiving. And I've bought up StopTech's inventory of these, so they are sitting in stock in New Jersey and ready to ship. Those of you in California who were dreading sales tax can now save another $330 on your purchase. And shipping is free. See: http://www.m5board.com/vbulletin/showthread.php?t=46952
 
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