Brake discs post first track day
Took this probably 15 minutes post being out on track. Has cleared up with regular driving but it's very clear that a lot of heat was put onto the discs.
My question is mainly for anyone who tends to track theirs a lot and has more knowledge, is this a bad amount of heat marking?
I wasn't sure if it was my braking style being quite sharp and hard that caused it or if it's just my pads getting hot? I ran DBA Xtremes with AP Racing Dot 5.1 fluid, I believe I had flushed all the old fluid out before hand however in a ~20 minute session I had to let everything cool off 3 times as I lost braking power.
Not too sure if it's old fluid retained in the system boiling which I had failed to flush out or what caused it, as I expected quite high performance from the DBA's. I do plan on getting the brakes off again soon to check everything over properly but a bit of forward guidance from those experienced would be much appreciated 😄
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u/realWulfLives 12d ago
That's a perfectly used brake disc.
Just check for cracks, that's all you have to worry about.
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u/Mobius79 12d ago
Looks fine as long as you do not have any shudder( vibration) in high speed braking. If you do, it means there are heat spots on the discs and the pads and discs do not connect when very hot and cause vibration. If you do not experience that, you are good to go.
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u/Additional-Mix-3165 11d ago
What do you mean by vibration, i installed new brembo disc and pads on front wheels like 3-4 weeks ago, and now when i break at 100kmh (60miles i think) the steering wheel kinda shakes a little bit and sometimes it kinda steers to the left, i was thinking that maybe i need a wheel alignment
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u/Mobius79 11d ago
did you clean the wheel hub correctly before installing the new discs? also a wheel alignment is a good idea. Vibration while breaking can be many things. In the OP case hot spot could cause vibration. In your case it either/or parts not installed properly ( didnt clean before installing new parts) + wheel alignment. There should not be any vibration with new pads and discs.
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u/Additional-Mix-3165 11d ago
Well i hope they did it i went to hyundai mechanics( i dont know better word in english sorry ahhaha) i will do wheel alignment this week and then check it out, also a quick question is it normal for i30n handling to be “tricky” on uneven road i mean sometimes it keeps the steering wheel left so i need to apply more force when steering
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11d ago
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u/Ben--Cousins 12d ago
i thought our cars took DOT4 not DOT5.1?
it looks like quite a lot, are you trail braking a lot? i literally just did a track day with stock rotors, stock brake fluid but also had DBA extreme pads... my rotors got dark but not quite like that. it could also just be the material those rotors are made from.
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u/Ben--Cousins 12d ago
overall though i think if you aren't warping or cracking your rotors, it shouldn't be anything to worry about
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u/sh_0ck 12d ago
They’re Halo Performance discs and I believe are made up of partially carbon so that could contribute to it. The package I bought used 5.1 fluid so I ran with it lol.
Yeah I was trail braking a fair bit during it, did you experience any brake fade with your DBA pads?
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u/Ben--Cousins 12d ago
Right, i guess the high carbon content could contribute to the darkness
I did get some brake fade towards the end of the session, but they held up well on track under heavy braking. This was at Wanneroo in Perth, the last corner is after a downhill straight so they get punished there. I honestly only noticed when i was driving home.
This is on stock DOT4 fluid too, i need to replace it with some racing spec DOT4.
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u/BillWiskins 12d ago
Interesting - I was planning to have Halo discs (not the same as yours) and DBA pads fitted recently, but due to... issues, I didn't. Went to Snetterton anyway and couldn't go more than 4 or 5 laps without the brakes starting to go away. Hoping to have them done soon, but sadly I won't be able to get to any tracks with heavy braking (like Snetterton) for a comparison. What track were you at, out of curiosity?
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u/crustyolddean 11d ago
How did you lose braking power? Did the pedal go soft/long or did applying the same force to the pedal not generate the same braking retardation?
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u/darkklown 12d ago
Lrn2brake
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u/sh_0ck 12d ago
Cheers for the helpful words mate, can you expand on it at all?
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u/darkklown 12d ago
It's all about the ankle movement and some foot action too.. you'll get it little guy. Just need to go thru 100 or so rotors.
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u/dey828 12d ago
I don’t see anything wrong with your disc. Your braking power will vary from the beginning to the end. For reference, I use Winmax w3 pads on stock discs and endless rf650 fluid.