owali

I was thinking of buying some new drilled rotors, but now I am not so sure. I read this on EBC's website:

BRAKE ROTORS
Grooved or plain vehicle type should be recommended to customers.

Almost all cars come originally fitted with plain undrilled or grooved rotors. This is mainly due to manufacturing costs and the fact that rarely are cars designed for sport use out of the factory gate. Higher performance cars such as Porsche and faster BMW’s are more recently coming fitted with “through drilled” brake rotors. EBC provide slotted and part drilled sport rotors for many import cars. The advantages of a slot on the brake rotor is it helps to prevent pads from glazing and to brake down the surface gasses which are generated under heavy braking on sport use i.e. track day, autocross or fast road use. The part drilled holes also add to the surface de-gassing. Many customers ask why our holes are only part drilled through the rotor, the answer is that because all original equipment rotors including EBC’s are what we call “straight vaned” in other words, the ventilation slots go directly from the outside towards the centre of the disc as they are not “scoop vented” there is absolutely no point in through drilling the disc. Scoop vented rotors require through drilled holes so that the air scooped into the centre core of the rotor can vent out through the holes. If through drilling is done on standard straight vane rotors it often results in an imbalance of the rotor, can weaken the structure and promote cracking of the rotor, that is why we don’t “through drill” at EBC.

ARE ALL AFTERMARKET DRILLED ROTORS STRAIGHT VANED?

Kharizma

iTrader: (6)

um.. i have cross-drilled and slotted rotors. no problems with mine. no cracking or nothing. maybe that off balance thing might have a point lol since i have shaking at 50mph and when i brake.. weird? i'm gonna get another alignment though and see what's wrong with the car. but i wouldn't worry too much about it, get it from a reputable brand. brembo, rotora, stop tech, i think there's some on e-bay that are good as well, not sure though.

Joelseff

For most of us (80-90 percent of GS owners) we dont really need the Cross drilled or even slotteds for that matter unless you take your car to the track on weekends. I had a miata that I used to dog on the twisties but never got around to track days. After the stock rotors wore out I replaced the stocks with slotted rotors and mintex pads. The brakes were substantially better than the stocks and they cost about the same as OEM. SO I would go with slots when time to replace your rotors unless you need the extra venting from cross drilled but I have heard of stories of drilled rotors warping prematurely and even cracking under stress. Also the slots would also serve as a wear indicator on your rotors.

slickgt1

iTrader: (1)

I have personally witnessed a drilled rotor brake on my friends car while autocrossing. If it wasn't for him being a dumba$$, we would still have the tape. The amount of damage it cost was horrific.

Regardless. There really is no more need for cross-drilling a rotor. This was the case 10-20 years ago, when brake pad technology was still poor. The gasses that built up were reducing braking performance. Now, you can buy a better pad and put it on a blank rotor, and acheive better performance. Remeber, you efectively reduce brake contact patch by putting in holes or slots. You get fracture points, which very few get because they are not abusing those rotors hard enough. You may think that your brakes won't fade with holes in them, but they will. Your fluid will get hot, and cause a mushy feel.

If anyone wants sick brakes, get some crazy pads, some nice brake fluid, and great tires. Everyone will envy your brakes. Everyone who drives my car loves my brakes. And I don't have any holes in them. lol

You can do more research on the web. Drilled rotors are mostly for show.

Oh and those manufacturers that have their cars come with drilled rotors, it is different that what we are buying. They have a different application, different cooling. It is there for a reason. My friend just removed the cross-drilled rotors from his E55 AMG, put on Brembo blanks, Axis Ultimate Pads, and couldn't be happier. He is convinced that his car brakes better.

David1969

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