1-2clutch-u: How old were those brakes before the track abuse? It looks like you might have had all that rust contributing to the pads debonding... in addition to the heat of course.
I set my stock brakes on fire yesterday and they didn't debond. I didn't lose the pedal either, they just had friction fade. I'm running some generic mystery pads :3d_frown: and brand new Altrom rotors. The pads are white and burnt looking on the edges now, and I had a horrible screeching after they cooled down from glazing. I'm thinking I might do a pad upgrade for now, eventually I'm planning on doing the Cobra brakes.
About upgraded stock brakes though... (I'm stubborn to give up on something without exhausting all options)..
If the R-4S compound is fading at the track... why not try the R-4E? I'm not sure what rotor temps you guys are seeing on the track, but AFAIK unless you're approaching 1200 degrees you're not heating the rotors up to a failure point. The R-4E has a much higher friction coefficient than the street version, and handles heat MUCH better. It's friction levels are higher than the street version at low temps too, so it looks fine for street use other than some noise and extra rotor wear. Usually "racing parts" are no good for street use, but there are exceptions. I know that R4-E compound is common for DSM guys to run on the street, actually, RRE specifically recommends it on their site (and has for a LONG time).
The downside is, the R-4E are pretty damn expensive as far as brake pads go. ~$190 (compared to ~$70 for R-4S).