Warpath said:
Drilled rotors aren't really necessary anymore. Modern brake pads don't produce the gasses the old pads once did. The holes only weaken the rotors and can start cracks. I have seen in MM&FF (or another magazine) pictures of these cracks. They don't recommend them either. If you want to do them for looks, thats another thing.
I have to respectfully disagree with some of this post.
Modern brake pads still produce too much gas at high temps, unless you go with a high-performance brake pad such as the Hawk HP+ (for autocrossing) or EBC "Greenstuff" Kevlar pads (for street use), which I use. The difference between the EBCs and "regular" pads is simply amazing. Check
http://www.tirerack.com/brakes/ebc/greenpads.jsp for more information on these. Doubtful that they're available for your cars, unless Marquis pads fit. Perhaps you'll want them for another car you have.
I also use cross-drilled rotors. You are correct when you say that stress cracks can develop, and they do
if the holes are drilled. If the holes are
cast into the rotor, this phenomenon is practically eliminated. Porsche uses this method ($$$). The problem with drilled holes in a rotor is that you can chamfer the holes on both sides of the rotor but there's no way to get at the INSIDE part of the holes, and that's where the weakness is. When you cast the rotor with holes, you can include the chamfers on the inside by design.
Slotted rotors are an option for those who don't like cross-drilled rotors. They still vent the gasses produced when pads start burning and seem to possess superior structural integrity. Look here for an example:
http://www.tirerack.com/brakes/ebc/rotors.jsp. I may go this route next time, as hairline stress cracks have indeed developed in my rotors. I guess hard braking from triple-digits will do that.
Damn, the car sure does stop though.
Here's a pic of my brakes so you can see what I'm talking about:
Braking is just as important as acceleration. Good thread.
Eric
