Myardor

iTrader: (7)

Slots scrape off the glaze
Crossed drilled holes provide ventilation.
but dimples?
tia

NotAPreppie

slotted/drilled/dimpled all do the same thing; allow outgassing of the pads under extreme duty to help prevent fade.

Some consider dimpled and slotted better than drilled as they are less prone to cracking.

I8U

iTrader: (1)

^+1

9krpmrx8

iTrader: (46)

^+2

Pico

iTrader: (2)

+3 Yep. that's basically it in a nutshell.

Fencig

So dimples cool like drilled? I've been looking to upgrade my brakes and other areas and would like some info on what each item does. My stocks stop me fine now but I'd like to track her soon and want to improve my handling/stopping for it. Dimples would seem to wear on the pads more but I've never used either.

swoope

iTrader: (5)

dimples dont start cracks..

holes do. unless the rotors are a billion dollars..

beers

E.M.S.

Had stillen x-drilled on my old probe gt. I pushed that car into the 140-150mph range quite often. Brake fade non existant. Rotors would glow red hot quite often, never had warping problems, never saw cracks, chews trough pads pretty well though. Prepare to replace pads every 8-10 months depending on habbits. Had those rotors for 3 years, verry little wear.

rodjonathan

iTrader: (6)

^ ive had mine on my 8 for a while drilled slotted and no problems yet (knock on wood)

ndhoffma

FWIW, it seems that a lot of experienced people on the forums don necessarily recommend dimpled or slotted rotors over the regular ones for track unless you're really pushing the car hard... sounds like upgrading pads is the best way to spend $ in this area, or at least that's what others who seem to know what they're doing say. There are a few brake threads out there that have some good info on this.

Ive only tracked mine once, and had no issues w/ the brakes. I had HPS pads & plain rotors on. But, keep in mind im pretty beginner when it comes to track/autocross, so take it for what its worth

I8U

iTrader: (1)

Oh man thank you! This was the funniest thing I've heard in a long while.

Myardor

iTrader: (7)

I understand that dimpled are less prone to cracking
the pro
whats the con?

I can see where the holes cool the pads/brakes, ie cooler air comes in from the back
but in a dimple> no hole so no cooler air coming in from the back
So how does it cool or maybe just cools less?
might not make a difference if one does not push those brakes much?

I did not know that slotted did the same as holes
I thought slotted were for scraping the glaze.
did i learn wrong? maybe also cools a bit but no hole in a slot so no cooler air from the back.
I figured each did a bit different
slots one thing..scrape glaze
holes cool but may crack wrap if too many of them
dimples cool but less and less prone to cracking/warping but not guarantee
tia

NotAPreppie

You think it's cooler closer to the engine?

Little holes aren't going to help with cooling. The amount of additional surface area is fairly small compared to the rest of the rotor. Actually, they will reduce heat capacity by removing some mass that could be absorbing heat energy. Also, they tend to reduce non-track braking capability by reducing the amount of friction surface. The vast majority of the cooling comes from the vanes internal to the rotor.

Heat capacity of rotors is really, really high. It's amazing how much heat energy you can put into a well-made rotor before it fails.

The bigger issue staying in the effective heat range of the pad. Different friction compounds have different characteristics. Regardless of the compound, when the pad overheats, the material starts to vaporize. When that happens, it puts a gaseous boundary layer between the pad and rotor resulting in reduced (zero) friction. Dimples/holes/slots all allow that gas to escape and keep it from interfering with brake operation.

Myardor

iTrader: (7)

So for the most part, ie non track, normal everyday driving
they are mostly for looks?

NotAPreppie

Exactly.

YaXMaNGTO