Agreed. I need to change them. I can't stand this dust anymore.

 

Drilled holes are still stress risers though. A rotor that was drilled could be stress relieved I would assume.

I used slotted 2-piece rotors with my Stoptech setup on my previous car and liked the rotors. No issues but I only tracked them one season before selling the car.

Personally I wish I could manufacture some cobalt rotors. Would be slightly heavy but one set for life

 

Regarding dust - drive with some Pagid Track pads for a week and experience dust . Makes the OEM brembos look totally dust free

 

This. You want dependable rotors that will stop the car, stay away from ported rotors. They don't last. Additionally, the multiple high-heat runs and cool-downs at a track day accelerate their fatigue and shorten the life of the rotor even further. Slotted or at most dimpled rotors are as far as one should go in terms of dependability and longevity. The rest is for show cars.

 

I'm good with electronics hardware and software, but not so bright with materials and mechanics. What do you mean by stress relieved? I think I need to educated on this topic.

 

You can treat the material to relieve stresses. Depending on how the part was made, there will be certain stress present internally. For cast rotors, for instance, you can heat them up to a certain temp to relieve the stresses and reduce the chance of breaking.

There is also something called a stress riser, which is basically a small area of the material where a crack is much more likely to occur due to how the part was made or machined. This is why drilled rotors are bad, all those holes become stress risers, which is why there are often cracks starting at the holes. This usually happens when there are sharp angles in metal pieces. This is why you often see parts machined so there are soft arcs where there are right angles, instead of their just being a perfectly square corner right there. That square corner has a lot of inherent stress and will crack more easily then other areas of the part.

 

Learned something new today. Good info! Thanks.

So you can stress relieve by changing the molecular structure (heat) or the mechanical properties (shape). About right?

 

Yes, although it's a bit more involved then that. That's really a basic idea of it all as I'm not a metallurgist, I just learned some of it being a crane operator and having to inspect various parts for stress risers.

 

I'll bet you know the difference between a left and right hand lay.

 

Ugh, inspecting wire ropes were the bane of my existence.

 

I would have to dig thru some old text books but basically iron can have different crystalline structures and said crystalline structure can be deformed during machining operation. If the metal is brought up above a certain temp it goes into austenite phase. This is for lower carbon steel. This realigns the crystalline structure stress relieving the metal. Then depending on the cooling rate, the crystalline structure will reshape and stabilize in one of a couple states.

http://nayhan.files.wordpress.com/2008/06/phase_diag_iron_carbon1.png

 

Some good info up ITT. Derek did the muff deletes arrive??

 

Some mis-information and a few good pieces, but here's the rundown on rotors:

Cross-Drilled
As previously mentioned, high end cars are NOT DRILLED. The rotors are cast that way. Drilling compromises the material and weakens the rotor. This is for looks only.

Slotted
It was previously mentioned that this reduces surface area and isn't great for performance. It's actually the opposite. The slots provide channelling for gasses, material and moisture to escape so the pad can clamp down more effectively. They also help reduce glazing on the pad to keep the actual pad material closer to its peak performance.

I love slotted rotors personally, and will put some on when the time comes to change them.

Pads on the other hand, like others said, I can't stand the dust. I detail the car and drive down the street for some gas and I can wipe my finger on the rim and it comes off black. I'm ditching them for some StopTech Street Performance pads when the car comes out in spring. I've used them in the past and was very happy with how they performed along with how little dust they produce.

 

Yep arrived today. I arrive home tomorrow. Should be able to toss them on for a little drive Sunday before officially garaging the car for the winter. Owe you paypal when I get back!

 

Nice! No worries/rush!

 

Just throwing this in, but I thought brake "dust",... home "duster?" I've been using the Swiffer duster to clean the wheel barrel. Works great. No matter how clean the outside is, if the barrel is dirty, it looks bad, especially on a black wheel. I still clean the outside and nooks and crannies with a microfiber.

Back to the thread, I like my Stop Tech Street Performance pads.

 

If your car is a DD do not get Drilled! Mine came with some drilled and slotted ones and I had a front one crack within a month of owning the car!

 

Total waste, well almost.

They will not stop you any better, in practical terms. Theoretically, in the track setting, the slotted rotors will suffer less from heat dissipation, and have less fade. The two piece rotors will also help in this regard a bit. Honestly, I haven noticed.

In the track, you"ll burn through rotors, like pads, etc. so why spendy.

The two piece rotors will have less rotating mass, which is interesting, but I'd rather put the money towards a lighter clutch/flywheel or one piece DS.