BOOTYTA

I would agree on some of your points. However, a top of the line car company using a certain type of brake on a high perfomance car cannot just be because it looks cool. I have to believe that there is some benefit.

Hell I autocross and have slotted rotors and they have worked great! Never warped. I only had them on the front and they have lasted over two years. The rears I have replaced twice in the same time and they were just regular blanks.

Cal

iTrader: (1)

Oh yes it can. It's called marketing. Engineering department says "slotted rotors are not need." Marketing departement says, "but they look cool, people like them, and we will sell more cars." Guess who wins this argument.

BOOTYTA

[QUOTE=Cal]
Actually did some research and companies like Porsche use forged rotors with holes in them and those are stronger than if you cross-drill a blank. So, they do use rotors with holes in them for a good reason. But, I do agree that most do not improve braking and can be weaker than blanks.

Corey R.

iTrader: (4)

what you just said, makes no sense. All you said was that forged with holes in place are better than drilling blanks, and thats why they use drilled.

VIP1

Do a search here on LS1Tech and you'll find plenty of pictures of cracked Porsche rotors. And you'll find a detailed explanation about the metalurgy involved. I dont have much time now, otherwise I'd search and post my findings.

BOOTYTA

Forged is stronger than drilling through a rotor is what I said. This I got from an engineer friend of mine that did some research on it. Are they better or worse than blanks, I really dont know for sure one way or the other. But forging a rotor with holes in it is the better way to get the cross drilled look without loosing rotor strenght. Just as forged internals in a car are better than cast ones!

Anyway, I did not realize that slotted and cross drilled had so little or no value compared to blanks. Now I do. I hope my slotted rotors last a while and next time I have to replace them I will try some high grade blanks and see how they feel with the same brake pads. Then I will know from experience.

JasonWW

iTrader: (2)

I don't think you will feel a difference in the 2 rotor styles.
If you plan on racing on a track were you will be braking hard and generating lots of heat, then maybe the blanks would be better. Anything less and the slotted/x-drilled should be fine.
I believe they will create more dust than blanks, so if that is a concern for you, maybe blanks would be the better choice.

Mainly it's the pads that you will feel. They can make the brakes feel like stock, to "Oh my God, my chewing gum is on the windshield!"
What specific pads did you get or want?

I tried some intermediate street pads that were quiet and only dusted a little (very easy to clean). They had little initial bite, but ramped up as you braked. I run R-compound tires all around so they are hard to lock up. The fastest I tried the brakes was from 90mph. They grabed like stock until the speeds got down to 75mpg then I could feel it ramping up. At 70 I was lifting out of my seat and the ABS was activating. Form that point on, I was a brake junkie.
I ditched those pads for some more hardcore ones, the Carbotech Panther Plus. They are real dusty and a bit noisy, but they grab instantly (strong initial bite). With a couple of stops in them (to get some heat in them) they are freakin outstanding. I have to be real carefull to not lock a tire under normal street driving, again with R-compounds. I feel much, much safer now and I'm starting to learn to use the new found stopping power and not lock up so often. I know one guy in a Z28 using the same pads can lock up his R-compounds at 120mph with out too much pressure. I haven't done any testing at high speeds, but I fully believe it can be done.

So pads can make all the difference. (these pads can't help but make me consider some 315 R-compounds for the front, but I digress)

kapsz28

iTrader: (6)

Why is nobody mentioning anything about cooling the brakes? Brakes warp from high temperatures. While I agree that solid brakes give more surface area, which yields better stopping distance, this is only true if they don't get too hot. Hot brakes=****. Most cars do not have adequate brake cooling devices to make solid brakes work well at high speeds. Which is why we have cross-drilled brakes.

As and FYI, Car and Driver did a test on all different brakes including stock brakes. It is very true that most performance brakes did not stop any faster, but they also did not fade. If you don't mind brake fade over 100mph, then go ahead and use your blanks. I prefer to be able to stop at high speeds. First time I ever brought my car to the track I had blanks with upgraded pads. I was very uncomfortable having to slow down from over 100mph after each run. Brakes worked less and less. After having cross-drilled brakes, my car never fades.


I have probably gone through about 5 sets of solid rotors. I also F'd up my cross drilled rotors. Right now I have dimpled and slotted rotors with ceramic pads. They stop great at all speeds and have lasted a lot longer than any other rotors I had.

VIP1

kapsz28, read the link I posted.
You'll find plenty of in-depth information on this subject.

Here is the short of it:
Blanks have more surface area, therefore they can absorb and release more heat than drilled rotors.

Rotors are basically heatsinks.
Lets make a comparison to computer processor heatsinks.
Do you see any holes in the mating surface between the heatsink and the processor? No. Its a solid surface. The fins on the opposite side dissipate the heat with the aid of a fan (or no fins and liquid cooling, but thats a different situation). Think of the fins and the fan as air running through the fins between the two friction surfaces of the rotors.

Not the best anylogy (there are dynamic differences in the two situations), but hopefully you get the idea.

Anyway, please read the thread to which I linked. There is plenty of info there on this subject. This subject just gets beat to death so much. It needs to be a sticky.

BTW, most brake manufacturers admit that cross-drilling in modern braking systems is for cosmetic purposes only.

kapsz28

iTrader: (6)

Then please explain why solid rotors fade more than cross-drilled.

crazyta99

i got slotted and dimpled from Power Slot. They made a big difference. I also put on a pair of Hawk Semi-Metallic pads thatr also made a difference. If I were you don't get drilled because thats a waste of extra money.

VIP1

Talk to trackbird or mitchntx.
They have much more experience with braking systems than I do and can better explain. Also, in the thread to which I linked, there is a thread with an in-depth discussion on brakes and another about what others on here have tried and currecntly run.

BTW, rotors are not the only factor in brake fade. Pads an fluid are a big influence as well. My guess is that you went from old pads/rotors/fluid to new pads/rotors/fluid and experienced better braking performance as a result.

Judd

iTrader: (1)

Hey kapsz28, you ever heard of sugar pills??? Plain and simple, drilled rotors are no good with the stock sized rotors on our cars. People have tried it, people that actually race or open track. If you are buying a set to go on your street car,,, then more power to ya. If your buying a set to go open tracking,,, then you are going to be disappointed.

Please try reading through the links that VIP1 posted. Do you really think that people that actually race our cars would refuse to use a set of drilled rotors just because they look blingy. Don't you think that if there was something that was legal to use in a class {or no class in the case of open tracking} and would improve performance, don't ya think they would use it? Heck, folks are spending alot of money just to gain a tenth or two a lap, I can guarantee that if it helped,, they would be alot more drilled rotors on road race F-bodies.

Everything that you posted has been argued to the hilt in the links posted, try reading them with an open mind. Look at the evidence given, then you won't be wondering why people that actually road race F-Bodies do not use drilled stock sized rotors.

UMD_Jesse

iTrader: (6)

Its my understanding that dimples are cosmetic and serve no function

GQ

iTrader: (5)

well, after doing some reading i feel a little more enlightened.. but would like to know the answer to kaps question... on my stock rotor/ pad lt1 it was very noticeable on repeated hard braking that the feel and force just wasnt there. i understand that the ls1's are equppied with better brakes and may account for some of the better high heat braking. i guess i also attributed part of it to the slotted rotors i have on. -g

ps. sorry to keep beating the hell out of the ol horse

JasonWW

iTrader: (2)

The author of this thread, 97SprChrgd383, didn't say he was racing or even ask about cooling.
You don't need additional cooling on a street vehicle.

kapsz28

iTrader: (6)

Haha, I wish my car had better brakes. I have never had so many brake problems with a car. I kept warping the stock rotors. I'm sure a couple times were from someone changing the tires and not torqing the lugs properly, but the last 2 times I made sure all lugs were at 100lbs and still had the problem. I was only getting about 7k miles out of the rotors. On the highway, they seem to fade quite a bit. Makes you nervous when having to do an emergency stop. If you brakes are any worse than mine were, I feel for you.

JasonWW

iTrader: (2)

Damn Kaps, that sounds really horrible. I know some of the automatic cars have more problems with brakes, but most M6 cars seem to do pretty well. You shouldn't be having problems on the freeway for sure. The long periods of not using the brakes should cool them to ambient. Are you saying that you can't do one emergency stop from 70 without getting fade?

Rotors aside, what pads have you been using?

Have you done some the usual things such as flush your fluid with some high performance fluid and bleed all the air out, make sure your calipers were not dragging, lube the guide pins etc...?

My stock pads/rotors sucked at higher speed just because they didn't grab that well. So the deceleration was not that great, but at least it didn't fade. My newest pads, the panther plus, are just wicked. I can't abuse them enough on the street. The hotter they get, the stronger they get and they bite hard as soon as you put your foot on the pedal.

Have you ever used an aggressive pad before?

Judd

iTrader: (1)

Dern feller,, something is wrong. I warped my front brakes within 10K miles but that was due to the lug nuts being over tightened. I had the rotors turned {generally a bad thing on our cars}, changed to Hawk HPS pads, changed to Motul RFB 600 fluid, whittled up some brake ducting and always checked the lug torque {I use 90ftlbs when lubed with anti-sieze} . Those pads and rotors lasted fine untill 40K miles when I changed to C5 rotors and Hawk HP+ pads.

I would recommend the HPS pads for the street as they don't really make any noise, they are not very dusty compared to some track pads and they don't eat up the rotors like some track pads. I'm OK with the HP+s but I only drive 10-15K miles a year and noise doesn't bother me.

If you want a brake duct set-up but don't want to figure it out for yourself, Severn makes a decent low cost set-up. Here is a link to mine- http://www.cardomain.com/memberpage/296918/7

I have since, redone the front scoops and air dam with scoops that are made for this purpose so please don't laugh too awfull hard at my dry-vac stuff.

kapsz28

iTrader: (6)

Most of my problems were with the stock rotors and pads. My guess is the problem was with the lugs being too tight. I drive the car pretty hard, so I have went through several sets of tires and had a good amount of nails/screws in my tires. I doubt most of the places actually torque'd the lugs to 100 ft lbs. My eradispeeds were doing well until I was on my way home from NC to NJ. Once again, I got a flat. I don't have a torque wrench in the car, so I just changed it using the wrench that the car comes with. By the time I had the tire replaced, that rotor was warped.

Right now I have slotted and dimpled that have lasted a long time. I am using ceramic pads. Pads feel nice and don't make any noise. I hate the hawks. My brother had them, and not only are they noisy, they require more force on the brake pedal for them to work.

My dealer did all of the stock rotors under warranty. Had the car in about 7 times. I think I had 3 different sets of rotors. The last time I brought it in, they wanted to replace all the pads and resurface the rotors. That obviously was not going to be under warranty. They wanted to charge something like $400-500 for the parts and labor. That is when I just went with aftermarket.