I've got the RR Racing SP 4pot front kit and I had a track day and it seems I have something interesting happening. Every time I hit the brakes hard, it seems sparks start shooting from my rotors. I've got some video but it's hard to see so I also took a screenshot from the video where you can see it pretty clearly.
Here's the video:
[ame="https://www.youtube.com/watch?v=_BQOlvR36b0"]shannonville fabi Sept 8 2016 sparks from brakes - YouTube[/ame]
I'll start by saying I'm not terribly worried. A quick check of the wheel, rotor, caliper and pad don't show any unusual wear, discoloration or scoring. I still have plenty of pad material and my rotors look good. At no point did my brakes start to feel or act funny and were completely fade free for the 2 half hour sessions.
A lot of the guys at the track suspect it is from high metal content in my brake pads but I have no idea if that is the case or what. I'm using the supplied BP10 pads from my RR Racing SP kit. We just want to be sure this is expected and nothing to worry about or a sign of any problems so I'm bringing it up here.
As you can tell in the video, the sparks seem to get more intense the hotter my brakes get since there isn't enough to be really visible in the video of the first pass, barely visible in the 2nd pass and clearly visible on the 3rd pass.
Edit: forgot to clarify that it was confirmed happening on both sides, in the front only. Rears did not spark, they are OEM with EBC Yellowstuff.