cracked rotors

[68sixspeed]

Hi- I know it's been discussed a bunch here, but for proof to the non-believer that drilled rotors are for looks and will crack, pic attached; now granted it took more abuse than I thought to crack them, fronts on my 2000 vette, approx 350 track miles to do it. (3-1/2 HDPE days), but also of worth while note- the holes become useless as they plug with brake pad dust. I kind of figured it was going to happen yesterday as after the 2nd 20 min run I saw the small cracks starting by a lot of the holes. It was a noisy/thumpy ride home!

[Apogee]

Nice. Do you mind sharing what rotors they are and what pads you're running?

Tobin
KORE3

[68sixspeed]

Brembo 1pc rotors (probably why they managed to live that long). 2-1/2 track days were on Hawk HPS pads, this last one was on HP+. No brake fade with the HP+. I know I got them hot, even on the HPS I'd burn the nickel plating (that's not rust showing, it's burned). Temps after 1 cool down lap and driving to my area in the paddock were at 600 degrees.

[greencactus3]

if they were clogging, i heard you should do more slots in the pads

[68sixspeed]

well, check out the rim, it gets a little dusty scubbing off 60mph just on the front straight every lap, let along the other 3 main brake zones.

[chicane67]

if they were clogging, i heard you should do more slots in the pads

Slots in the pads dont do too much when you have holes in the rotors. Pad slotting works better with solid rotors.

The fix to this would be to direct air to the hats and by paying peticular attention to closing the backing plate's with a properly designed duct... it then will blow the material out of the holes. It also may over cool... for the intended use.

[Vegas69]

Wow, those babies have been hot!

[68sixspeed]

Yep... driven like it should be. If you start doing these high perf. driving schools you quickly burn the dust boots right off the caliper pistons.

Chicane- the vettes have cooling ducts but they don't get right to the spindle/hub area (they blow on the inside of the rotor, not through the vanes) I'm adding the doug rippie motorsports kit to it over the winter it brings a hose right to the spindle/hub.

I posted this for a laugh and also confirmation on the cracking to those who haven't seen it. Solid rotors spider crack too but not as easily. I'm actually impressed they lived this long- I guess the lesson is that for street or autocross, the drilled will live just fine, but the repeated heat cycles of road course use will make them crack.

[chicane67]

Yeah... Doug's kit works nicely... we have used each others stuff for years back when we (Guldstrand) raced in the Challenge series against each other.

"Normalized" or cryo'ed Brembo blanks have the best longevity of rotors I have seen.