vd

iTrader: (3)

Installed Girodisc 2-piece rotors 14k miles ago, initially paired with Ferodo DS2500 pads. The pads lasted 10k agressive miles of spirited and competitional driving in summer with 245/40/17 Z1*. After these 10k miles rotors showed virtually no wear at all and looked almost like new.

Next set of front pads installed 4k miles ago is CL RC6E (E stands for Endurance) - adverised characteristics include very low pad wear rate and low rotor wear rate. However, I've done only 4k very light miles (actually that was one long trip to France for skiing with most of that miles being smooth driving on the highway, tires are 235/45/17 winters now) and front rotors are in fact done - wear is such that there is no slots on them anymore and thickness decrease is significant and easily visible. Also there is extremely large amount of agressive brake pads dust on the wheels and body of the car.

Beside this, everything else is perfect - stopping power is great, bite is excellent, noise very low (less than noice from DS2500). Pads wear over that 4k miles is also very low, only rotors are damaged.

The question is - is such wear rate (4k miles until rotors are over) normal for the set of high quality 2-piece Girodisc rotors and Endurance brake pads? Any reasonable suggestions and experiences are welcome.

Note - I am really not willing to switch to other brake pads as I liked the way the car brakes with RC6E. Right now I of course will buy another set of replacement rings for Girosc 2-piece rotors, but in the future it seems strange to me to need to change brake rotors rings once in 4k miles.

98vr-4

iTrader: (2)

I had the same exact thing happen with my DBA 4000 rotors and Carbotech AX6 pads on my VR-4. Hardly any wear when racing (lapping days and autocross) but 10000 miles later on the street and my rotors are DONE. Slots are worn almost all the way down, and uneven wear, towards the edge of the rotor has worn more. I still have about half my pad thickness remaining.

I contacted Carbotech about it and sent them pictures. They dont know what the problem may be. The AX6 was also described as a rotor friendly pad. I am not dissatisfied with its performance at all, just the wear rate.

I'm in the same boat as you, I just bought a set of used 2 pc rotors and dont want to be dropping 400 dollars a year on new rings....

Try contacting your rotor manufacturer. I am going to do that next, maybe there is some kind of compatability issue with the materials of the pad and rotor.

EVOBrakes

iTrader: (67)

The CL RC6 is a full on race pad - and sintered. This means that when cold they are operating in abrasive mode and thus can wear rotors quite fast as you experienced. This is common w/ all race pads - some are just worse at it than others.

In fact - had the car been driven harder on the brakes - the rotors may have lasted longer at least as far as abrasive wear to the min thickness. (Cracking is the failure mode under track conditions)

The DS2500's are a street/light track compound. They make the switch from abrasive to adherent at a much lower temperature (around typical ambient temperatures) and thus you were primarily in adherent mode which is where your pads need to be. They do have a very wide operating range though which makes them a favorite on cars like EVO's STi's etc. Not too much bite/wear - but very hard to fade and great feel.

As far as rotors - there are differences in wear.

Materials and alloying, heat treating, tooling design etc - they all come into play. 4k of street driving is off the scale though. I wouldn't expect the rate to change w/ those pads -you need something a little more street friendly.

-Ken

Girodisc Martin

iTrader: (71)

There is the possibly that there was pad contamination on the rotor that could explain this. Every pad needs to put down a layer of pad material on the rotor so that it has good adhesion to the rotor when you apply the brakes. This is called a transfer layer. When swapping pads the new pads need to ware off the original pads transfer layer before it can put down its own transfer layer. What can occur is that the old pads transfer layer does not ware off completely and this will cause your new pads to ware incorrectly. This can cause excessive heat which can ware the pad or the rotor down extremely fast but there is no real way to tell for sure.

vd

iTrader: (3)

Thank you very much for the detailed and clear explanations. It appears that my case is exactly the one with lower than needed temperature, consequently abrasive mode operation and consequently ultrafast rotors wear.

Is there reasonable expectation the situation is relatively low dependent on the ambient temperatures? I mean it would be virtually the same in 25C outside (now it was about -5C) and key factor in determining rotors wear is type of usage (i.e. racing vs DD)?

EVOBrakes

iTrader: (67)

Certainly exteme cold will make it worse but ultimately race pads take some heat to start working properly. 2-400 degree's F is a reasonble number so of course in 80-90 deg F summer weather it will happen pretty quick while in below freezing temps it may take a few stops. In colder weather it will also be much easier for the pads to cool down well below their range.

Now in the case of DS2500's - we would give an approximate range of say 100-1100 F but another consideration is that the pads are already not nearly as abrasive so even when they are very cold the abrasive wear would not be so rapid.

Cliff notes - CL's higher end race pads are not cold temp friendly. Hawk Blues are notorious for that - I've seen slots gone in a day btw.

That was somewhat quickly typed - hope that is clear. I think the 2500's are a great pad if you have that kind of cold weather.

vd

iTrader: (3)

Got your idea, Ken! Must admit your knowledge and experience combined with willingness to share them are just awesome.

One last comment, please. Is there any brake pad with more braking power compared to DS2500 that will be as kind to the rotors as DS2500 and cost less than arm and leg? Essentially, the pads that are suitable for DD as good as DS2500 (relatively low dust, relatively low noise and ready to give bite in very different conditions) but have more braking power.

Looking through your website I've noticed following models:

1) Carbotech AX6 (marked as street pads)
2) Porterfield R4S (street as well)
3) Hawk HT-10
4) Carbotech XP8
5) CL RC5+

Could you please comment whether any of those listed above can give rotors a chance to survive reasonable mileage (more than or very close to 20k miles) if used for DD or I should just stick to DS2500 and use RC6E for racing events (this part with RC6E for racing only is now clearly accepted).

Also, from your experience, is it fine to just switch the pads from street to race before racing events and after the event changing them back. Any additional procedures are needed (taking into account we change one set of used pads that has it's contact with rotors to another set of used at that moment pads that had their contact with rotors before) or it is just as easy as regular change of the front brake pads?

Again, thanks for the information and experience - I very much appreciate knowledge sharing, especially if it comes from the person who know what he is talking about really good.

Smike

iTrader: (8)

DS2500s has a drag coeficent of .50. Satisfied and Axxis had pads that matched that. But, indeed, they don't make them anymore.

EBC RedStuff has a .50 drag. I ran a set on my SVTF. Lots of cold bite. Low rotor wear. Low dust.

Hawk HT-10, Carbotech XP8 are track pads. CL RC5+ have a .4. A little bit less bite.

I did just as you did. DD pads on all 4. Then for track days would switch over to my race set (HT-10) and drive to track gingerly on them. Race all day. Drive home gingerly again. Swap back to front DD pads.

wrcRS

That is exactly what I was thinking.

I too have had Hawk Blues eat a set of rotors in a weekend. Couldn't get enough heat in the tires or brakes that weekend.

EVOBrakes

iTrader: (67)

Ferodo's DS 2500 are not high friction pads. You should have noticed a distinct difference when going to the CL's. Two other pads in the category are Hawk HP+ and Carbotech AX6. The Hawk's just seem TOO loud at times but they have great cold bite and decent temperature headroom. Probably the best autocross pad ever made and great for entry level tracking on cars that don't kill the brakes - on an EVO or STi or similar heavy fast car they can be overheated perhaps a bit too easy.

The Carbotech's might be the right pad for you. They are a less abrasive pad in nature then Hawk's or other more metallic compounds yet the AX6 have good bite and temperature headroom. They are a bit more finicky w/ rotors though so I would suggest that swapping them w/ CL's could easily lead to bedding issues. They are basically the polar opposite - Carbotech's have less metal - and CL's being sintered are all metal.

We do have quite a few Corvette and STi/WRX users running Carbotech XP-8's on street/track but maybe not in such cold temps. I'll shoot them a note asking about that - what is your lowest ambient you might see? The XP-8's are mild race pads - but the nature of Carbotech's is that they are not so highly abrasive when cold so if you really need the high end performance it might be a better choice.

EVOBrakes

iTrader: (67)

That compound is pretty old and very ingrained into the market so it's not going anywhere. It's the exact wrong pad for an EVO - not enough for hard tracking and *not good* if used on the street. In it's defense though - when used on a car such as a specMiata race car it has ample friction and fade resistance, rarely has bedding issues and lasts a LONG time. Like 12 hours at 'hard on brakes' Summit Point on a Neon ITA I crewed for a few years back. We won that race btw - I was the gas man.

-Ken

wrcRS

Good point, I forgot to mention that this was on an ITS FC RX7.

It was raining throughout the weekend and temps were down in the 50's. I learned a lesson that weekend.

vd

iTrader: (3)

Typically in winter (November-February) we have ambient temperatures in range of 15-40F, in summer (May-September) typically temperatures are in the range of 75-95F.

EVOBrakes

iTrader: (67)

You could run XP-8's or Hawk DTC-30's without too much issue. May screech at times but that's what EVO Brembo's do w/ aggressive pads in them.

GTWORX.com

iTrader: (35)

DTC-30's would be good or Pagid Blue RS-4-2 (a bit expensive for pads but very good).

Ken knows brakes!

- drew