05-21-2019, 03:17 PM | #1 |
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I have some 8 track days on the OEM rotors and both the front rotors are starting to show these micro cracks. I run PFC12s.
I don't think this an issue (yet), but it should be monitored. Thoughts? |
05-21-2019, 08:11 PM | #4 |
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Those look pretty good! You should only be concerned once cracks start connecting to the holes.
It’s technically not covered under warranty, especially if you have discolored calipers (the dealer will know you’ve tracked the car), but if your dealer likes you, they’ll get one set passed BMW for warranty and goodwill another for you. That’s if you’re lucky! |
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05-22-2019, 06:08 AM | #7 |
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My AP rotors always had the same small cracks after a couple of trackdays...just keep an eye on the edges of the rotors and the holes (with the OEM rotors).
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05-22-2019, 08:35 AM | #8 |
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Completely normal.
This is a great article about the M Sport brakes from a BMW engineer - https://www.bmwblog.com/2014/04/13/n...-brake-system/ Last edited by M2joey; 05-22-2019 at 08:53 AM.. |
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05-22-2019, 08:49 AM | #9 |
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Same as Franzino my AP rotors have small cracks all over them. I only have 10 days on them, and suspect the rings will need to be changed close to 15-20-days.
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05-22-2019, 08:55 AM | #10 | |
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05-22-2019, 09:03 AM | #11 |
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Yeah, I’m the guy that not only does the slow down cool off lap at the end of a session, but also drives out of the paddock onto the access roads to cool down my rotors further!
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05-22-2019, 10:35 AM | #12 |
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Same here. Last time I stopped right after cools down to talk w my instructor (Pitt Race), the wheel weights' glue melted off the wheels and the weights started to fall off. I try to do al least 5 more minutes of cool down after the cool off lap.
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05-24-2019, 07:10 PM | #13 |
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Shouldn't be a concern. Those micro cracks are completely normal.
Looks like you are getting good use of your brakes. I would measure the thickness of the rotor to be certain you are still way above the min. thickness before your next track day. |
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05-24-2019, 07:22 PM | #14 |
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I did. Was at 13.2 mm.
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05-24-2019, 09:02 PM | #15 | |
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So, the engineer reckons ceramic brakes are the way to go Out of curiosity does anyone know how much the M carbon ceramics cost? |
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05-26-2019, 06:34 AM | #16 | |
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https://www.bimmerworld.com/Brakes/B...112358378.html This will be one thing I investigate when I attend a One-day M school in Spartanburg later this year. The same amount of money would certainly cover the cost of A LOT of replacement rotors and pads for the latest M2 Sport brakes (2HN). https://f87.bimmerpost.com/forums/sh....php?t=1497066
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05-28-2019, 12:30 PM | #17 |
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Not to mention you literally have to baby the carbon ceramics - they chip extremely easily (have to replace the rotor) and you can't measure the life left with a caliper, you have to weigh it.
I've also heard they don't last the "lifetime" of the car under heavy use on the track, so unless you really need the performance benefit you're better off just buying 4+ sets of steel rotors/pads. |
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05-28-2019, 03:29 PM | #18 | |
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http://www.brrperformance.com/blog/?p=3127 |
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05-29-2019, 07:43 AM | #19 | |
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I have heard that most in the Porsche community do not opt for the carbon brakes if the car will see regular track use. If money were no object would they be the best, possibly. Look at the brakes kits the come on most supercars. Although, when it comes to most race cars they use steel brakes. Very interesting topic.
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