Drilled vs Slotted vs Drilled&Slotted

[racerx]

So, I'm seriously thinking about getting new rotors, pads, and lines for both the lude and the accord.
I hear some people saying drilled will crack if you don't "break em in" right...
And some say that slotted will wear the hell outta the pads...

So I'm assuming drilled&slotted is just a double helping of trouble...

How badly will pads wear with slotted discs? (Axxis semi-metallic pads)
How likely will drilled discs crack?
Does the zinc plating really protect against rust? For how long?

Anyone seen those black discs? Will the black just wear off after a day of driving (where the pad meets the rotor)? Or is it "blued", that metal chemical treating that's been put on many military rifles and guns.

[3gn86lxi]

Hey racerx.....
Whats the break in?? I just purchased cross drilled rotors for my wifes astro van. I was told to run semi metallic pads with them, they assured me that they don't crack much anymore, but I don't know anything bout the break in.
:alc:

[bobafett]

the black zinc coating WILL come off of the area where the pad is applied.
ROTOR DRILLING DEFENITIONS:

The purpose of cross-drilled slotted, or dimple rotors are to dissipate heat caused by aggressive driving condition.

CROSS DRILLED: Holes are drilled through the rotor increase the surface area and to promote the dissipation of heat. It will prolong the life to the pads, rotors and improve stopping power. It also shed off water under-wet driving condition.

SLOTTED: Lines a trimmed out of the surface of the rotors to dissipate heat and increase bite. Slotted rotors will bring up the operation temperature of the braking components much faster over cross-drilled, yet it dissipates the heat at the same time. The added bite will reduce the stopping distance. Slotted rotors do not sacrifice the structural integrity of the rotor.

DIMPLED: Gives the appearance of cross-drilled rotors without sacrificing the structural integrity of the rotor. It also does not wear the pad as much as an all slotted design.

Cross-drilled/slotted or dimple/slotted will give you the best combination of performance and longevity. It will dissipate heat and increase bite for better stopping power.

[nswst8]

If that. The black finish as you were talking of is only a protective coating for the non friction surface of the rotor.

anytime that you have friction between two surfaces any coating will wear away. Very quicking concerning brakes.

The break in as you are talking about is the mating of the pads to the rotors the creates the wear pattern which I would expect would take no more than about 100 miles at the most. :thumbup:

Good luck.

[racerx]

right on! thanks a lot everyone!
yeah, I saw some rotors that actually were coated black all over, I'm guess to save time... don't have to worry about tapping off areas or whatever. It would be bad-ass looking if it could stay that way though. Hmmmm ceramic brake discs?

I guess I'll be going with slotted and drilled. It's gonna look sweeeet!

[Justin86]

Yea the only problem people have with the cross drilled is them cracking on extreme breaking as in racing every weekend. Slotted and dimpled is all I would use, esp for a street car.

[bobafett]

Yea the only problem people have with the cross drilled is them cracking on extreme breaking as in racing every weekend. Slotted and dimpled is all I would use, esp for a street car.

yeah im going with slotted dimpled on the 240 and possibly the accord ;) its the best way IMO

[3gn86lxi]

I had a warping problem when I put the 18's on the van, so the cross drilled will keep the temp down and I won't be racing so no worries bout them cracking.
I'm also going to use carbon metallic pads. :thumbup:

[Hash_man_Se_i]

You don't necessarily have to be "racing" to have cross drilled rotors crack, especially when using more aggressive pads like carbon mettalic. And the cracks are usually fairly minor, but are never a good thing, and I would imagine any crack could make the breaking of the vehicle unstable.

I plan to upgrade to slotted rotors fairly soon, as personally I think they make most sense. IMO, i dont see the logic behind slotted and drilled, or slotted and dimpled. When upgrading brakes, you want to maintain, or gain surface area for the pad to contact, while also improving the dissipation of heat from the rotors. Using two methods clearly takes away from surface area for the pad to come in contact with, and IMO makes sense to just have either slotted, or drilled, personally I'm going slotted.

[dillirk]

slots dimples and holes remove heat as a secondary objective. They are primarily designed to remove the gasses created from the pad breaking down from the heat. (not sure how the physics works on this) The gasses build up and form a cushion betwean the pad and the rotor almost like a lube... bad for breaking.

[Justin86]

yea that is the manin objective, and the one thing I hate about blanks. You could get cross drilled for streets, but really paying the extra money for them is a waste and not necessary. If you were to drill them your self that is another thing or dimple them.

[bobafett]

yeah the main reason to buy upgraded rotors is to reduce brake fade. yes you will stop faster do to a more aggressive pad, and more bite, but the primary objective is just to reduce fade. if you want a STRONGER brake, that will stop you faster you really need bigger/better calipers, and larger rotors.

[Hash_man_Se_i]

I think lots of you should get the new HCI mag, and read the article on brake upgrades... It's quite usefull...


If you were to drill them your self that is another thing or dimple them.


That's just asking for trouble.

[NashvilleLX-i]

i heard Drilling the rotors yourself is NOT a good idea because the rotors do becomse weake that way. but Cross drilled arent drilled but jsut forged with holes in them so the brakes should stay just as strong as without drilled. and i dont understand dimpled because the slots in slotted rotors are long so the gas doesnt stay under the pad but if they were just dimples i dont think that would carry the gass very far. but if anyone is willing to drill slot or dimple their rotors just let me know how it goes but i dont think it is a good idea at all. you just dont mess with brakes.

[Mike's89AccordLX]

I have the spendy EBC Sport Rotors and they are slotted and dimpled. From now on I will just buy the cheap $12 rotors at napa b/c I'm not too happy on how they are after 2 years. They do stop better but unless you actually race a lot I wouldn't recommend them.

[steven]

ive heard drilled rotors crack, but i dont know since i dont have any.

[Hash_man_Se_i]

Drilled rotors are proned to cracking as said before. This is under high stress high heat situations.

[racerx]

I have the spendy EBC Sport Rotors and they are slotted and dimpled. From now on I will just buy the cheap $12 rotors at napa b/c I'm not too happy on how they are after 2 years. They do stop better but unless you actually race a lot I wouldn't recommend them.

Why aren't you happy with them? Are they warping or something? Rusted?

[Mike's89AccordLX]

I think that the rotors might be slightly warped. I get a vibration under mild to heavy braking. That's why I think if you don't race you should just get the cheaper oem rotors.

[3gn86lxi]

I've had my new drilled and slotted rotors on the van for about two weeks, and I'm very happy so far. Major difference in stopping power. So we will see with time weather or not they warp.
They look awsome too. :alc:

[Ludi Mali]

The break in as you are talking about is the mating of the pads to the rotors the creates the wear pattern which I would expect would take no more than about 100 miles at the most. :thumbup:

Good luck.

I was always told to do that with any setup of pads and rotors. And i've found it extends the life of the pads by almost double. Just brake easy for the first 100 miles so the pads and rotors have the same shape.