windyC6

Yea....my rotors are drilled and worrying about them cracking has never even crossed my mind...esp. for street use....and I don't think i'd worry much about them cracking in moderate track use. I think theres too much forum "balderdash" going on......and please.....no pics of any cracked rotors .....

Shaolin Crane

I've had some spectacular failures with drilled rotors, like halves of the rotor breaking off. My point was it's not a performance upgrade in any way. They probably won't crack (unless on a track) but will be more prone to it.

Fletch F. Fletch

OP, I believe there are slotted only options out there as well, if u r worried about drills cracking.

mikeCsix

Plain rotors provide higher performance for stopping power. Think of the loss of surface area with all of those holes (or slots) drilled into the rotor.

NormWild

Don't listen to all these naysayers, drilled/slotted rotors look way better, and they wouldn't put them on every high performance track focused car made today it they didn't improve braking. It's not about surface area, its about gas release. Mine is a Z51 and I replaced mine with DBAs all around, they have been great.

Shaolin Crane

No, they don't.

windyC6

Yes surface area is very important. But cooling is very important also. Anyone that has ever driven a car to extreme and then have the brakes start "Going Away" could attest to that.

jchappies

For a street car you're not gong to notice the difference. If you need more surface area you could go to bigger calipers/ more pistons/ larger brake pads/ or larger disk. There are many ways to accomplish the braking you need but for this purpose the Powerstop kit or any drilled or slotted rotor will work for a street car.

Shaolin Crane

Except the holes don't increase cooling capacity as they are run perpendicular to rotational airflow of the veins. C or J hooking is what you'll find now a days on cars still affixed with iron rotors. Even F1 brakes aren't drilled.

KNSBrakes

Half a day on track

C6Z06 rotors

da_mulag69

Thanks! Will push forward with my new upgrade

mikeCsix

Some inaccuracies here, there is looks and there is performance when it comes to brake rotors. Pick one. "Outgassing" isn't the issue it once was, the biggest issue with hot rotors is pad deposits at red lights. That is what gives you the pulsing brake pedal most everyone thinks is warped rotors. Drilled rotors may be okay for autocross or drag race tracks, but you will run into problems on a road race track as others pointed out. The holes become useless because the fill with brake dust anyway and holes or not they still crack.

Glad you like your DBA's, I also run their slotted version with a race track focused brake pad for track days, and a ceramic pad for street use, the compounds in the pads are compatible so they are easily interchanged without having to resurface the rotor or burnish the rotor/pad surfaces.

HOXXOH

I created a drill template to drill base (JL9) rotors to look like J55 rotors. I kinda did it for looks, to fool people into thinking I still had my OEM J55 rotors, but it was really for weight savings.
Maybe the OP would like to buy my templates and drill his existing rotors.

TucoTom

Doesn't Wilwood make brake kits for the C6 Base model (JL9)?

hawkgfr

Agree and drilled are prone to crack around the drilling with use so I would avoid those just for that. Slotted if you have to have something lol...

edit for
I see others have supplied very good information as always..

windyC6

Why are we trying to compare F-1 brakes for this thread? F-1 brakes are a completely different animal. F-1 brakes are designed to get better the hotter they get. Actually F-1 brakes are crap until they do get hot. Not sure why people are always trying to argue the laws of physics. If you have two identical pieces of metal and you cut holes in one of them.....then bring them both up to the same high temp......the one with holes in it is gonna cool quicker. Not only is the mass reduced, but the cooling due to ventilation is increased..........

HOXXOH

Actually, a differential rate of cooling is why rotors crack. Those with holes have multiple opportunities to crack. To help against the severity and early demise, machining a full radius around the entry/exit of the drilled holes, eliminates the material where the cooling that initially occurs at the edges. Polishing the radius further reduces the chance of cracking. Looking at the pics KNSBrakes posted, you can see radially oriented cracks around holes that either have countersinks or sharp edges. The cracks are radial because the outer diameter of the rotor got hotter and cools quicker.

Another part of the cooling problem that includes non-drilled rotors, happens when a car with hot rotors comes to a stop and doesn't move again. The area covered by the calipers doesn't have the same rate of cooling. To avoid that problem, move the car a couple feet every few minutes.

Shaolin Crane

Exactly, which is why I showed brakes from LeMans cars and motorcycles as well. Eirher way. F1 cars don't run the same pad or rotor compound every race, just like what was mentioned they change depending on ambient temperatures or rain. They would never run hot weather setups in the rain for the exact reasons mentioned, however once once they're hot, braking dynamics are still the same.

To the bolded part from Hoxxy. Road course cars get a cool down lap for this reason. Where you're supposed to make your entire lap without applying the brakes at all. The times I see the biggest problems are limited cool down then applying the parking brake. Still, you can do everything right and still break apart a drilled rotor. I have a box of them somewhere. Beyond thermal cracks I have never broken a blank rotor, and once switching to only slotted never had another thermal crack either.