Autocrossing Rotors
 

well, my stock rotors finally got some small cracks in them so its time for new ones. i have hp+ pads going on with the switch. i am prepping the car for autocross but i do drive to events and would like to be able to attend track days/hpdes without having to put a whole new brake system on. looks like napa rotors are fine if you have ducts but i would like to take this opportunity to shave some weight. cant run titanium rotors (must have 100% ferrous material for the friction surface not to mention i dont want to dump $4k into rotors) so i guess id be running stock or two piece. any recommendations?

The lighter the better, but can you afford them? The replacement two piece are to costly for my use.

I've had heat-checking on my rotors (a.k.a. "spider-webbing") for the past couple of years autocrossing. I'm running PFC Z-rated pads, and have a set of HP+ pads waiting when these go away.

I understand about reducing rotational mass, but the rotors aren't that far away from the hub centerline, as far as inertia goes, and reduced mass equals reduced braking capacity.

HTH, and have a good one,
Mike

For AutoX you should be fine on stock or NAPA rotors.
HP+ pads are very streetable ... little harder on rotors than stock Z06 pads.
I used them for HPDE as well with street tires. I'm not as hard on brakes as some (and have DRM ducts withhose and spindle mounts.)
I'm mounting CarboTechs 10's/8's for HPDE now with Nitto 555rII's (yes, I have to drive to the track ...)

Remember to break in the pads with the old rotors.

are there 2 piece stock sized rear rotors? seems like its either:
stock
stock sized cross drilled, slotted, etc. 1 piece
big brake kits with 2 piece rotors

I use Raybestos PG + solid rotors from Rock Auto... $100 delivered for 4

What class santioning body are you running in?

I would go with AC Delco stock or the NAPA replacements and toss them once they begin to show cracking. The NAPA rotors aren't expensive and are widely available. The Hawk HP+ pads will work fine with stock-type rotors and will work great on the street once they get a little bit warm.

Ducting air to the rotors won't hurt, shouldn't cost a lot and they won't weigh much at all.

SCCA SM2, possibly NCCC Class III but right now I'm sticking to SCCA until I can free up some more time.

unless you're in the running for a national championship and are trying to shave off hundredths of a second, or have money to burn, stick with the NAPAs.