mikegarrison

Holes are holes. The "cast holes are different than drilled holes" thing is a myth. Holes don't cause cracks because they have been drilled; they cause cracks because they are stress concentrators. It's a matter of geometry and metal properties, not manufacturing technique.

Even the cast holes get finish-machined anyway.

Now I'm not saying a poor manufacturing process can't make things worse, because it can. Improperly drilled holes can be worse than carefully drilled holes.

Slows2k

Product inquiry, moving to S2000 talk

dmw16

This is not a true statement at all. Drilling a cast part interupts the internal structure of the material. It also creates residual stress from the machining process. No matter how the holes are created they still can create stress concentrations, but a cast hole is stronger than a drilled hole.

All that being said, the drilled ones just look bad-ass. I saw a Lambo today at the Home Depot w/ big drilled rotors and it looked awesome. Also saw a new M5 earlier in the week w/ similar rotors...again, awesome.

mikegarrison

Got a reference for this? Something written by a metalurgist, not something on some brake rotor company's website? Or are you a metalurgist?

We aren't talking about single-crystal exotic metal turbine blades here, we're talking about a mass-produced cast iron brake rotor.

Residual stresses can be removed by heat treating.

Jasonoff

Sure if your pads were made in the 60's or 70's

SpitfireS

Ohh well.. but they look


Allthough on the Stoptech website they do mention slotted / drilled rotors have some benefits, mainly to provide a place for "debris" to go.
Brake dust isnt something from the past, I mean, I only have to look at my wheels.

They also mention drilled rotors are more likely to crack during track conditions.
And Stoptech also makes plain rotors.

I'm not trying to prove my point.
Not at all.
Because I know I have no point to prove.

But..
They look

Emil St-Hilaire

Hockey

I chose to go a different route. I picked up some slotted and cadmium plated rotors from Centric (thanx Spugen) almost 2 years ago. I like this brand in particular because the slots do not go all the way to the edges, like the Power Slots for instance. That is another place where cross-drilled and slotted rotors can crack, since there is less material there. The cadmium plating keeps the rust away pretty well, except for the pad contact areas ofcourse but that gets swept away after a couple touches of the brake pedal. The plating doesn't last forever and you'll get some rust in the venting (fronts) and the hat (center).

-Hockey

dmw16

Direct reference, no? Just what my professors always told me in my materials classes.

Jasonoff

No worries. Gas is not an issue anymore so when they put that shit up on manu websites it's a crock.

Slots "can" help prevent glazing "if" the edges are sharp but it's not necessary.

As for evac of brake dust. If you figure a 215/45-17 tire revs at aprox 820rev/mile @ 60mph that's 820rpm or around 13-14rev per sec. At that speed I'd be checking the inside of your rims or fender liner for the dust