imstimpy

By my count that is 4.25oz o.0

DefSport

Just to follow with this, there is always play in these components under load. Excessive rotor runout is going to make it seem worse.

rioyellows2k

I'm glad everyone else chimed in on the pads being inappropriate. I would not use anything less than a DTC 70 on the front axle of a track application. Hawk pads are known to leave deposits. If you're running pads past their operating temps you're basically smearing them on your rotor. Those microcracks are normal for track use and it's not a concern until it you can catch it with a fingernail or it goes to the edge.

I've been using Cobalt's on my track cars for 7 plus years and I've never had a problem with smearing or deposits. OP claimed issues with noise well he should know there doesn't exist a track pad that is quiet.

Also Doesn't matter the brake kit, you need brake cooling to get the most out of it.

DefSport

DTC-60s are fine for almost all cars. The only cars I've seen that really need a DTC-70 or 80 are high HP GTRs or Corvettes.

I use DTC-60s on the front of my S13 that makes like ~320-350 rwhp now (turned back as far as it'll go), and it does fine on Wilwood Spec 37 12.19x1.25" rotors, no ducting. The rotors pump so much air that I took the ducting off, picked up a tad of speed on straights (less drag) and the last set of rotors lasted me around 50-60 days... give or take. Lost track in there since I installed them in 2010 or 2011 I think. They actually wore out to min thickness before they cracked all the way through. The medium duty rotors cracked clean in two in around 6 days, so double the cost for the Spec 37's was well worth it. The AP Racing rotors are on par with the Wilwood Spec 37's, so that's why I find it really hard to believe they cracked already on OP's car.