Tifosi

Does drilled brakes offer better cooling than the slotted types? TIA

ZephyrS4

Some say that they do

Imolavirus@BuehnEngineering

I dont think that you as a driver are going to be able to tell the difference between the two

Jeff Vader - boscoj

often tends to weaken the rotor. With more metal in a slotted rotor you have the greater ability to sink heat.

2000ImolaS4

Drilled brakes look cooler (in both senses of the word), but in fact, the slotted rotors tend to do a better job of cooling the brakes. Furthermore, drilled brakes have a tendency to form small "heat" cracks at the holes and the rotors are more likely to warp as well.
If you think about it, the drilled rotors actually have less metal to dissipate heat, thus they get hotter and have greater difficulty dissipating the heat than a comparably sized slotted rotor.

Tifosi

Thank you all for answering my thread. Much appreciated.

Hibiscus Red S4

That's good enough for me. As long as they're brakes designed drilled, and not simply a stock rotor that's been drilled as an afterthought, they should be cooler than slotted types. Slotted allows the brake pad to get more grip and is good when stuff gets on the rotor.

01blackS4

i think drilly cracks, hence the casting.

sloting/grooves can be cut after the rotor is cast and has had the surface honed

Hibiscus Red S4

You want the ones that ARE cast, not drilled afterwards (some of them).

NoahD

Now, Porsche "drilled" rotors are actually cast that way, as 01blackS4 said, and they're OK (though they do crack on occasion, as do all rotors under real heavy use). But actual drilled rotors (i.e. where they take the stock rotor, and drill it) are dangerous. A blue TT at lime rock last year had his front right rotor EXPLODE, taking his wheel and caliper with it, while on the track. Could have been a lot worse - nobody hurt, and the tire contained much of the debris and held that corner of the car up. Please, avoid the aftermarket-drilled rotors. Slotted is fine.