plain vs. cross drilled vs. slotted vs. cross drilled and slotted

[zooguy]

i have heard many things about them and i want yalls input. do they really stop any better? do they just look good? advantages or disadvantages?

go

[Paulster2]

The purpose of the holes and slots is to assist in cooling and releasing gasses which are produced off of the pads during braking. The only problem with either is the cross drilled rotors tend to crack around the holes. This is caused because stress risers form around the holes, then the heat from braking exacerbates the issue. You can help the situation by reaming the hole a little bit by putting the rotor on a flat surface, then place a medium sized ball bearing on the hole and hitting the ball bearing with a hammer. This bevels the edge and reduces the sharp edge which the stress riser forms off of. IMHO, leave the cross drilled rotors for the track. It's not worth the hassle. They do look cool though. ;)

[jaysz2893]

well i used EBC dimpled and slotted OEM replacements with thier Red Stuff pads on my HHR when my stock rotors warped for the 3rd time (common HHR problem). The rotors now have 20K miles on them and they have not warped. I cant say for sure but it does feel a little better when braking as far as distance. The theroy behind the rotors is the slots and dimples allow the gasses made by the friction of the pad to escape and makes the stopping distance less. I will say that they are louder than OEM brakes. I researced a lot for OEM replacements and EBC seemed to have the best track record. I used to work for a company that made ceramic composite rotors. We made prototypes for Brembo. The large rotors we made for race applications were actually solid face (non drilled/slotted). The ceramic cooled faster than metal, but the engineers said that drilled rotors tend to develop stress cracks at the drilled holes. This is why just dimpled seems to be better for OEM replacement. Drilled and slotted work fine in race applications and especially in larger diameters. The pads are a very improtant part of the equation as are the type of caliper. The larger the pad and more pistions the caliper has the better the braking will be. Those 2 factors dertermine the contact area on the rotor and how much stress the rotor will see. If you are going to to a big brake upgrade then go for the biggest rotor that will fit with the best caliper and dont cheap out on the pads. You can do drilled, dimpled, slotted in that application with no problem. If you are staying OEM, then the EBC I used will be much better then stock for wear, but dont expect a huge performance gain. I just put EBC dimpled and slotted (OEM Replacements) with the Red Stuff pads all around on my Camaro too. Mainly casue the stock rotors and pads were ready for replacement and I like the looks too. Also the pads (after break in) will produce less dust which is nice.

[Paulster2]

We on the same wavelength Jay? :metal:

[jaysz2893]

LOL. I guess I was typing while you were posting.

[Paulster2]

LOL. I guess I was typing while you were posting.
Yah, I type like a mad man ... I'm surprised the "Backspace" key isn't worn out :D

[zooguy]

so there is no real gains or i guess decreases in stopping distance that will be useful in auto x ?

[NebWS6]

so there is no real gains or i guess decreases in stopping distance that will be useful in auto x ?


Well in auto cross you are going to be heating those things up and the last thing you want is brake fade.
I run an "in the middle rotor"...I use ATE rotors
Try getting ahold of Sam Strano as he is the auto-x brake guru. He recomended mine to me. They work better than the stockers but I also upgraded to LS1 front brakes.

[Paulster2]

so there is no real gains or i guess decreases in stopping distance that will be useful in auto x ?
The biggest benefit is reduced fade in the brakes, which I would assume is extremely important in auto-x. If you consider that a gain, then yes they do. Stopping distance is mainly going to be affected by tire traction, rotor diameter, caliper clamping force, suspension stability, vehicle weight, and a few other factors.

[zooguy]

so they will help with brake fade?

[Paulster2]

Yes.

[zooguy]

but not with stopping power?

[lttransam]

i love my drilled and slotted rotors.. the only bad part is i have to buy some more for next year :(

[MoeHorsePower]

You also have to beware of some pads that say for racing only, people think that if its good for a race car then it should be even better for a street car,,Not so. Some pads that are developed for racing purposes actually react to heat, the hotter they get the more stopping power they produce. This is good for continuous high speed stopping or road course driving but for street, they are not good, How do I know, I tried some and they sucked on the street, After I did back to back high speed stops, then I could feel them grabbing harder..

[Fastbird]

Dimpled and slotted at most if it's a street car. If there are cross drilled holes, they WILL develop stress cracks. Even Call911's car with the big Baer brake system, he's got stress cracking at the holes on his rotors.

[95ImpySS]

Well Ive been doing lots and lots of reading about brakes.

Drilled, dimpled, slotted factory thickness and diameter rotors are worse for stopping power and brake fade because of less material. Only way to reduce brake fade and increase stopping power is to increase rotor mass. Drilling, slotting, and dimpling removes material thus reduces heat absorption.

Quoting Bill Harper here:

"Todays pad formulation don't actually have the out-gassing issue that older brakes did when operated at high temperature--today, some pads don't even begin to work until temps reach a certain level. This is not so much for street as in racing, but some street pads CAN be significantly temp-sensitive. Trial & error, do your homework on this.

I will say this about slotting--it will reduce pad life and create more brake dust, since the slots are constantly acting as a "grater", shaving off a minute amount of pad material with each revolution of the rotor. Bottom line, plain rotors provide the greatest mass and longest pad life. For hard-driving with occasional strip use and towing, I have no problem with either plain or slotted rotors--and I don't really think the + vs - on slotted rotors means they'll work much better--otherwise the factory would be doing it. If you don't mind the extra dust and quicker pad wear, go slotted."

[CALL911]

X-drilled rotors are simply for eye candy purposes only. They WILL NOT help a bit with stopping, lessening brake fade, or anything else related to stopping. They WILL stress crack eventually also.

Slotted rotors may help slightly on venting, creating a small margin of decreased brake fade.

If you want a good setup for hardcore road racing, just get a thick set of blank rotors. And no matter what route you take, get them cryogenically frozen. This increases the longevity, and if you do go with cross drilled rotors, it will prolong the stress cracks.

My setup:
I have a Bear track pro setup on my Z, with X-drilled, slotted, zinc washed, cryogenically frozen rotors. Yes, I know I just said they do nothing to help you stop, but I will say the cross drilled rotors look sexy, and that alone is worth it for me.

The biggest thing you can do to help inprove braking is ditch the stock LT1 setup. LS1 setups are quite a bit better and can be had for not much $. If you really want better stopping power, you'll need to drop the big bucks and get an aftermarked setup like I did. Willwood 6 pistons are just as cheap as my Bear big 2 piston setup (but funny enough they don't stop as well). Brembo, Bear, and Alcon are some very good brands.

This year I am seriously considering upgrading my Bear two piston to a GIGANTIC set of Bear 6 piston brake calipers. But I am crazy like that :devil:

[95ImpySS]

Check out this kit: http://kore3.com/proddetail.php?prod=10105-03

I purchased the Kore3 325mm kit for my b body. I must say its a nice set up. DBA rotors are serious. Pick up the DBA 5000 2 piece. mmmmmm :heart:

FWIW, the number of pistons only designates how evenly the pressure will distributed to the pads. Piston area is what will determine how much clamping force is achieved for a given fluid pressure. Piston area also changes pedal feel and biasing. Only thing that will significantly lower brake fade is rotor mass. The higher thermal capacity of the rotor the longer it will continue to stop.

The slots on rotors is for shaving off build up on the pads.

Any modification such as drilling or slotting to a rotor without increasing its mass only hurts its thermal capacity. Thus brake fade will occur sooner during braking.

Drilled slotted rotors are sexy.

6295

6296

[CALL911]

Check out this kit: http://kore3.com/proddetail.php?prod=10105-03

I purchased the Kore3 325mm kit for my b body. I must say its a nice set up. DBA rotors are serious. Pick up the DBA 5000 2 piece. mmmmmm :heart:



Did you do research before getting those? I am guessing not. In short, the C6 Z06 brakes are horrible. There are threads all over the corvette forum about guys swapping to anything other than the C6 Z06 brakes. I saw them for a good price and looked into it a while back, and I'm glad I did after what I found.

FWIW, I know that the number of pistons are not directly corrolated with stopping performance. However in Bears 6 piston brakes the pistons are the same size of the pistons in my 2 piston setup, there are simply another 4. Essentially I would be getting 200% more braking surface than my current setup.

[95ImpySS]

Just figured Id throw what I know about there for others. I didn't know the Bear had 4 more pistons the same size as your 2 piston. %90 of the time they are slightly smaller pistons. That must be a huge caliper.

The only thing Corvette about the package I posted is the calipers. I did extensive research on the b body forums when I purchased my b body kit. Ive read nothing but praises about them. I'm curious what the problems are with the vett brakes. Not a single problem reported with the brakes on 4000lb cars. Some of which auto cross. :confused:

Edit: Just realized, the kits I researched use the c5 z06 calipers.

[CALL911]

Just figured Id throw what I know about there for others. I didn't know the Bear had 4 more pistons the same size as your 2 piston. %90 of the time they are slightly smaller pistons. That must be a huge caliper.

The only thing Corvette about the package I posted is the calipers. I did extensive research on the b body forums when I purchased my b body kit. Ive read nothing but praises about them. I'm curious what the problems are with the vett brakes. Not a single problem reported with the brakes on 4000lb cars. Some of which auto cross. :confused:

Edit: Just realized, the kits I researched use the c5 z06 calipers.

Bears' 6 piston calipes are quite a bit larger than their 2 piston setups. You have to run an inch larger wheel (minimum), and the caliper covers quite a bit more of the rotor.

Yeah, the C6 Z06 brakes really suck. Sorry you are hearing this after you bought them. Maybe you could return them? There are lots of options in the same price range that are better choices.

I would like to see someone try out one of the new Camaro (5th gen) Brembo brake setups on a 4th gen (or even another car), just to see how they do performance wise. That might be one option. But there are others if you choose to return your Z06 set and are interested in other options.

SORRY for setting this thread in a different direction.

[96SilverRam]

I'm going to second the Wilwood 6 piston big brake front setup. I've had mine with the 4 piston two piece Wilwood setup in the rear and the stopping ability of the car is night and day. I will agree that there are a few kits that will provide some marginal gains for a little more money, but if all you do is 90% street driving its more kit than you will ever use. Plus, it just looks cool x-drill/slotted :D

http://i5.photobucket.com/albums/y194/96SilverRam/DSC01858.jpg