The failure mode on those rotors looks more like a design flaw (too little material in the hat to surface transition to handle the heat load and stress). Or just poor casting.
Scary
'99 9.3 - Torquey noodle-mobile.
'08 9.3 SportCombi - Family Wagon.
'87 900 - 8 valves of pure fury.
'91 Legacy AWD - Sold
'74 MGBGT - Stage: Welding project.
'87 4Kquattro - Gone, but not forgotten
Sorry to bump an old thread, but I can now add my name to the list of those with a broken rotor at SLMP. Waited one event too long to replace the stock Brembo rotors apparently. Happened on about the fifth lap, which ended up being fortunate because I was able to get a new set overnighted from TireRack since nobody local stocks Evo rotors (including the Mitsu dealers). They only had 21K miles on them, but something like 6 or 7 weekends at SLMP included in that. Looked almost exactly like Ryan's - broke around the hat. Fortunately didn't damage anything else.
I replaced them with Centric since that's what I could get - will have to keep an eye on them after reading this thread.
_______________________
Jim
08 Evo X (DD/toy)
97 Impreza (winter beater)
I'm surprised you had any braking up front with the spring borked like that. I've forgotten to put them on my car and gone for test drives...scary pedal feel. Hope everything else went smoothly and held up for people!
'99 9.3 - Torquey noodle-mobile.
'08 9.3 SportCombi - Family Wagon.
'87 900 - 8 valves of pure fury.
'91 Legacy AWD - Sold
'74 MGBGT - Stage: Welding project.
'87 4Kquattro - Gone, but not forgotten