denlin68

So I understand that cross drilled rotors are prone to cracking under extreme driving and braking on the track .....so all the cross drilled rotors that i look at online says "not for tracking use"

so then how come all the porsche, BMW Ms and other high end sports car all comes standard on their cars? and people do track those cars as well ... soooo

Is their cross drilled rotors better quality?

or maybe their cross drilled rotors are really thick?

or is cracked rotors happens to a very small percentage and we on the forum overhype it?

I like the way they look and would like to track my car so i dont want to have problems with the rotors ...

nudge120

iTrader: (2)

Those high end cars rotors are not drilled, they are cast with the holes in them. So the structural integrity is not compromised like it is in a drilled rotor.

jcnel_evo8

iTrader: (2)

+1 to Nudge -- if I were to put a list of factors on the rotors from Porsche / BMW / etc ...

1 - The holes are cast
2 - The holes are designed with anti-cracking in mind
3 - You're going to pay a lot more for these rotors - with that in mind I'm sure there is some insurance built in (under warranty) in case these also crack, and some customer starts to whine about it.

Rotors are religion and feelings get hurt ... yet ...
90% of all the drilled rotors on the Evo are for the uneducated and posers. I'm sure there are some "race cross drilled" rotors for the Evo, that are manufactured and high quality like the Porsche and BMW ones, but I'm not going to spend the time to look for them as my poser meter and money meter both get pegged.

My brake time should be better spent trying to get a pad / rotor combo for inexpensive so I can go race.

If I'm at a "car show" and start looking at brakes, what I like to see is (semi-educated self) are:

Rotor Quality / Build - Hat Material - Spring Interface and Design.
Caliper Quality / Build - How many pins to pull to get things swapped.
Pad Quality / Build - What are the race teams running?
Brake Line Quality / Routing - What makes it easy to get in and out of the calipers?

Function, Fit, Form mean a lot more than poser holes drilled at the customer's eventual cost.

~j.

denlin68

many good point guys .. so no aftermarket vender sells cast cross drilled rotors ? i wanted to know how much more expensive they are ...

i really like the drilled look but i want the good cast quality not the drilled kind (without over paying in mind)

jcnel_evo8

iTrader: (2)

Finding anything is going to be a pain ... (at least for me) ... It might require actually adapting a caliper at this point ...

Another good article.

http://www.6crew.com/forum/showthrea...d-and-the-ugly

denlin68

great article! .... makes the 2pc rotor looks way over priced because its 4.5 lighter and since the hat and rotor arent bonded together the rotor has to do all the heat dissipation.
Normal rotors the hat is in contact with the wheel so it can transfer some of that heat to the wheel as well... but 2pc rotor design the hat is in contact with the weel but the hat is only screwed in at mulitple screw points only.


Looks like giordisc high quality 1pc slotted rotors for me

AlwaysinBoost

iTrader: (17)

IMO you are fine using the cheap(er) x-drilled rotors on teh street and even for the occasional track day, but just keep in mind they WILL crack on you... its only a matter of time.

I've cracked two sets of drilled rotors on two different cars and I'll never run them at the track again. Both cars had ducting to the rotors and I know how to use the brakes.

You can easily tell when they crack too because it will feel like there is something inbetween the pad and rotor when you press the brake pedal.

If the 'look' is what you are going for I would suggest slotted over drilled.

meckert

iTrader: (11)

Try slotted rotors---they work, look nice and dont crack

ezzey

iTrader: (3)

+1 to above info
+1 for slotted rotors

USCGSAM

iTrader: (6)

i have slotted and am satisfied....

denlin68

thanks guys looks like slotted will be what i am looking for!

FJF

iTrader: (18)

FWIW, I run slotted/drilled Baer rotors front and rear. To tell the truth, I didn't want drilled for all the reasons mentioned in this thread, but they were offered to me at a price I couldn't refuse, so I figured why not. 20lbs less rotational mass is nothing to sneeze at. I've had them for ~15K miles, maybe a bit more. I drive 99% street. This car is not my daily driver, though I do drive it almost every day. 21K miles on the car, 3 sets of tires and 3 sets of brake pads. The rotors are holding up. YMMV

559evo9boy

@fjf.. Are your rotors 2 piece baer? And we're did u get a good deal on yours?

Extreme Dimensions

iTrader: (4)

Why not be baller and just get these?



On a serious note, like every one else has said, The higher end rotors are cast with the holes in them , so the structural integrity is not sacrificed.


There's a difference between this 2008 Porsche 997 GT2:






2013 991 carrera S



And this (random evo drilled rotors)

AlphaKennyBody

iTrader: (2)

High End cars as mentioned above.... Those aren't your standard cross-drilled and slotted rotors. Those rotors above are made with an Ultra High amount of carbon which makes those rotors cool down rather quickly vs what you find on the market with cast iron rotors which are made out of a Grade 3000 (OEM) or companies like R1Concepts who sells a Grade 3500 rotor which is made with a high carbon count called their Premium Rotors.

Also, These race cars have the funding to swap out rotors every time and if they do crack they swap them out per event.

One last thing to know that lot of these rotors in "stock" trim "cross drilled/slotted" aren't that at all...... They are Dimpled vs Drilled.