Are they?

 

we switched to slotted rotors, because we get contingency. only measurable difference is that you now have a wear indicator, IE when the slots are gone rotor needs to be replaced.

 

Thanks... Still wondering if I should shell out extra for heat treated rotors.

 

No they are a waste. Buy high quality blank rotors and be done. Centric premium, or even better the high carbon line work very well.

 

I would think any heat treating you do would be altered/ruined after you heat cycle the rotors.

Rotors will often get hotter than normal heat treatment temperatures and the cooldown isn't anywhere near as controlled.

Now, if they were heat cycled before machining.... maybe that's a good idea? Or maybe it is cheaper to just get the rotors machined IF they warp after use on the car. If they warp from heat, they typically only do it once, machine them flat/square again and they will be good until they finally crack or wear out.

 

the only reason to consider slotted rotors in my opinion is if they're the only offering from a reputable company. For instance on the FD in the stock size I was using powerslot rotors in the rear. Not because I thought the slots were an advantage, but because they're quality made rotors and would last longer than the parts-store versions during track abuse.

If you're considering no-name ebay slotted rotors then pass.

On the front I'm using the AP j-hook slotted rotors. I wouldn't trade them for the world, but I don't believe their value is really in the slots but more that the rotors are made from great quality iron and take a ton of abuse.

 

Buying them before they are slotted is cheaper. Stoptech slotted or drilled rotors start out life as Centric Premium blank rotors.

The rotors on the back of my car are actually Centric Ctek economy rotors because that was all that was available. They are holding up great and come off the track at 500+ degrees every session.

 

Good info, thanks for sharing!

I am planning on replacing all 4 rotors this fall

 

Slots and cross drilling are a back and forth issue. Lots of OEMs (BMW M cars, Porsches, etc) use them. But in practice, racing, ive not found them to show any significant advantage. In fact ive seen cheap cross drilled rotors crack, many times.

What I have found is that good quality brand name blank rotors (brembo, centric premium, etc) that i've had cryo treated by frozen rotors have lasted by far the longest. Cheap rotors can warp and crack, even more so with slots or holes. Good quality blanks last a long time and give consistent performance. But ive observed roughly doubling that life with cryo treatment.

This is lots of first hand evidence over 10 years of racing.