Yeah slotted/drilled rotors are way better than blanks. The slots or holes act as vents allowing the gases made by braking to vent away from the surface of the rotor. This allows full contact with the pad and rotor, thus better braking power. The slots or holes also allow air to move through the rotor more freely, cooling the rotor considerably. All of this equals to a better pedal feel, less brake fad and shorter 60-0 ft times. This is a fact that for some reason some people just can't get. Look at any high performance brake kits, Porshes, Mercedes, Ferraris they all use drilled or slotted rotors. Humm if Ferrari uses them and they are arguably the best car makers in the world, then there may be something to it.

 

You need to do some more research; with modern brake pad materials, the gasses created by the brakes are reduced considerably. With drilled or slotted rotors, you're also reducing the total contact area between the pads and the rotors compared to blank rotors. As far as moving air, the air in the wheel wells isn't doing as much moving as you'd think. Could you please tell me what principle of fluid dynamics (or physics, if you'd like) says if there's a hole or a slot, air will go in it? Also, consider the fact that there's a heat shield immediately behind the rotor; yes, there's a small air gap between the shield and rotor, but what do you think this does to the air flow?

Better pedal feel = pads and bleed the brakes. End of story. The only real pedal feel you'll get from a rotor is when it's warped, and that's not better in most peoples' opinions.
Less brake fade = get bigger rotors with larger piston calipers or better pads (with a higher thermal capacity)
Shorter 60-0 times = get better pads and larger rotors/calipers that have more of a contact patch. The surface of the rotor has nothing to do with stopping distance.

As far as high performance brake kits go... well, what do you think has more of an effect on stopping cooling? The fact that the rotors are slotted and/or drilled? Or the fact that they're gigantic compared to stock brakes? Since larger rotors and larger pistons in the caliper (not to mention larger pads) basically equate to more clamping force on the rotor, I'm going to go with the fact that they're larger than stock brakes. And the cooling aspect? More surface area means the rotor can lose heat more.

By the way, both Porsche and Ferrari have already come out and admitted their rotors are almost entirely for looks. People think they want drilled and slotted rotors, and because of that, it sells. That's how car companies make money: they sell what the customers think they want. If drilled and slotted rotors are so amazing, why aren't F1 teams using them?

Hmmm... you know what? I'm pretty sure I don't see and holes or slots in the surface of the rotor. Yes, the cooling vanes are there, but they're also there on stock front brakes.


And also, take into consideration the rotor thickness around the holes in drilled rotors and in the slots on slotted rotors. Drilled rotors are notorious for cracking, and I wouldn't be surprised if slotted rotors cracked easier than blanks, especially when water and hot brakes get together (like they regularly do on the streets).

I'm not saying drilled and slotted rotors aren't worth it on a street car; let's face it, they look incredibly aggressive and sporty. But as far as better stopping power and improved pedal feel, bleed your brakes and throw some Hawk pads on and call it a day.


reference 1
reference 2
reference 3


Not trying to be an a**, just presenting my argument.


OP: If you still want to get drilled/slotted brakes, look at Summit Racing's in-house line of brakes; they're relatively cheap, and I can say from experience that they look great and stop the car just fine.

 

^Thank you Reaper. A long while back I did a bunch of reading on rotors and braking systems and agree with you completely. I just didn't feel like backing up my knowledge because I was feeling lazy and I didn't take note of the literature that I read all of it from.

I have slotted front rotors, yes, but it was only for the 'bling' factor.

btw [/thread]

 

^I would like to see your findings for the slotted rotors dissipating more heat. All of the sources that I have found point towards slotted rotors as not dissipating enough heat to be of significance. The order of most likely to warp to least likely to warp is...

Drilled and slotted, drilled, slotted, then blanks.

so you're telling me drilled and slotted are most likely to warp? what is the point of drilled and slotted rotors? i'm looking to upgrade my rotors and breaks since the guy before me seemed a little rough on them. i have an 07 civic. any rotors better than others?

 

i just read the post above by reaper after i wrote my initial post. if it;s just a bling factor with slots and holes, then, buying regular rotors should be fine. i just don't want to buy rotors now and have to replace them in 5 years or so. so any advice would help. yeah... i'm knew to this whole thing! thanks for any advice!

 

I dot need to do research I have an Assocites Degree in Auto Tech and Repair, I am a certified techinition. Yes modern pads like ceramic or semi-metalic give off less gasses then older organic or asbestos pads. But if you are putting your brakes under heavy loads like say racing where you are building lots of brake heat, the gases can cause fad and increase stoping distance. It will also build up extra head and glaze the pads and rotors, now you need a brake job. Ceramic pads have copper and steel in the pad this melts out of the pad if to much heat is made. I had many of these issues after just a few times at the track. Slotted/drilled rotors help a great deal to reduce brake heat. If you just drive your car around town under normal conditions then yes blanks work just fine. And F1 racing uses a carbon or copper rotor and high carbon pads to go with them, these only work well under higher temps. They also change the brakes pads, rotors and all several times in a race.

 

Nice try at credibility. No offense at all to your degree as I applaud you for actually going to school and becoming something! However, there is an engineering side, beyond that of common knowledge.

I will QUOTE BREMBO themselves....

"Slotted, drilled or dimpled rotors offered as OEM replacements should not be considered appropriate for high-speed track use.

While grooved, drilled and slotted rotors offer an enhanced appearance and add some resistance to the boundary layer of gasses that can build up between the pad and rotor, they are not designed to withstand the extreme temperatures that are produced on the racetrack. If they are used on the track, it is very important that the rotors be carefully inspected and should not be driven on if even minor signs of deterioration are seen. Note, too, that if any products are used on the track they are not warrantable."

When Brembo sells their slotted rotors they sell them as 'better than stock' with improved looks. They will tell you hands down that their blanks provide the best... ...THE BEST... ...brake performance.

[/thread]
...or should I keep kicking this dead horse!?!

 

Why is it then that I see everyday blank rotors coming in needing to be resurfaced if they are so unlikely to warp?

Were talking about street cars with street brake applications, not F1. street cars that run on the track don't run Hawk HT-10 pads.. Were talking about street cars using sub-$100 rotors and pads. Run Hawk HP+ pads on slotted and blanks in 20min track sessions and I'm sure you'll feel the difference in fade. I've ran Hawk HPS pads on OEM blanks and then I switch to the the PowerSlot slotted rotors and it made a difference. I ran back to back 20min sessions on track(basically 40mins straight) and although I felt some fade, it was not nearly enough to make me pull off and let them cool down.

Throw all the mombojumbo about F1 cars using large Carbon fiber composite rotors and carbon pads with 6 pot aluminum calipers with titanium pistons and military grade hardware...It's nothing when talking about a brake system that is suitable for street use with minor track abuse.

 

so... since i don't know much about the mechnical side of the car, blank rotors are fine for street use in general. my car has about 45k on it and sometimes i'm feeling the brakes pulsing. slotted/drilled rotors are for looks basically? i don't want to spend $180/pair on rotors if i don't need to. should i look into higher quality pads and not worry about rotors so much?
my expertise/knowledge is in the audio/wiring side of things. not totally ignorant when comes to mechanical, just needing some help.
thanks

 

The pulsing on the brakes would be runout in your rotors; in other words, they're warped. For normal street use, blank rotors and stock replacement pads will work just fine.

*edit: you could also have the rotors machined at a brake shop, dealership (I wouldn't recommend the dealership. The flat rate for subarus is 2hrs/axle, and I'd imagine Honda has about the same labor times. 2 hours at labor rates of $80+/hr would be a little expensive), etc, provided they can machine the rotor and still have it within specs.