Drive 2013 G37xS coupe (big brakes) with slotted rotors.
On my recent track day it looks like my front left race pad started crumbling a little and a piece grooved the rotor (one circular groove around).
I replaced the pads (still need to bed in the new pads). I do feel a little brake judder under hard braking.

1. should I replace the rotor?
2. can I buy a different brand set of slotted rotors for the fronts from those I have in the back?
3. very annoying that this rotor brand only sell them in pairs

Thanks for your help!!

 

If the groove isn't too deep you might get it machined, just have to find a shop willing to do it
Can Drilled/Slotted rotors be turned? - Corvette Forum
If you indeed need a new rotor have you contacted the vendor or manufacturer just in case they could sell just the single rotor?
G/L

 

if you've grooved the rotor, it means it probably also got a lot hotter near there which would mean the metal is somewhat compromised. if its a brand new rotor, its worth turning the rotor. if its got a lot of miles on it already, just replace it. remember the rotors only wear 2mm or so before needing to be replaced.