speedracer g37

iTrader: (4)

dimpled rotors also do the same, and as stated above, it is not only for quicker cooling.

RedG37SNC

Yea to a great extent it's about looks, here's the benefits touted by Brakeperformance.com, I can see some heat management benefits not sure about the better braking, no difference noted so far but then I'm not tracking the car.


www.brakeperformance.com
Full Sweep Scraper Slots dissipate heat, increases bite and reduces the stopping distance. Our slots also help to de-glaze and even out brake pads while throwing dust and debris away from the wheels. It also sheds water under-wet driving conditions.

speedracer g37

iTrader: (4)

drilled or slotted does not give you better braking or stopping power. it keeps your brakes from fading as a result of heat and gas disipation.

Rollin'onRays

but most modern brake pads don't have that much gas release from the pads anymore?

and having less mass (ie slotted) does not help heat dissipation, since there will be less mass for the heat to transfer too. It's not like the slots act as fans for the brake pads. With the temperatures that the brakes and rotors reach, the only way to make air cool them effectively is to have air ducts into the rotor area.

IMO you have a higher chance of heat soak in a slotted rotor than a blank due to less mass alone

here is a good read that i read up on a while ago, back in my honda days (ya ya, i know - i went to a fds3, then to this, so i went up the ladder :P)

http://www.honda-tech.com/zerothread...ostid=35728678

Rollin'onRays

oh, and if you are too lazy to read that entire thread - best part is here

"Find me an F1 car as of now that uses cross drilled or slotted rotors.
They all use full ceramic rotors and ceramic pads. Are they drilled or slotted? No.

If they helped the fastest cars in the world, wouldn't they use them? Its basic calculations that show the lack in surface area does not make up for the possible loss in temperarure. They use brake cooling air ducts insted."

Seer

I'll never run a drilled rotor ever, too structurally weak.

RedG37SNC

The camparison of requirements between an F1 car and street car are not the same... an F1 car get's it's brake serviced after every race... a street car doesn't. If however you look at performance parts for street cars, a much closer match, you will find drilled and slotted rotors. Why would they do that if it wasn't a benefit? That benefit may just be looks, although common sense would lead you to beleive they do help with heat, deglazing, dust dirstribution and water which in the end should improve overall brake performance.

Rollin'onRays

Even if it gets serviced after every race, how does that factor into it? Wouldn't you want the best stopping power for f1? Its not like having blanks makes the brake pads go faster. They would want to disapate heat as much as possible to be able to stop. Nascar problably doesn't use drilled/ slotted either. The mazda 787b doesn't use them either (from the pics i looked up on the internet)

They use slotted and drilled/ dimpled on performance street cars just for looks - nothing elese. Or why wouldn't all of these cars come with them from OEM? its less material, wouldn't it be cheaper cast that way? 2% material saved times millions of rotors = lots of money saved

RedG37SNC

We'll will have to agree to disagree... Race cars in general are designed for the hours they'll be raced on cleaned tracks, streetcars are quite different. Looks are definately a major selling point, the performance advantages could be negligable however I dought they would decrease brake performance and could possibly improve it.. we'll have to see some test to know for sure. The fact remains, high performance street car brakes do contain drilled and slotted rotors...if there wasn't a benefit they wouldn't included it because it takes additional machining to accomplish and that's additional cost. The Arc and direction of slotted rotors futher indicates there is a performance advantage.. this isn't just a slash, but it flows in the direction of rotation to use centrifical force to circulate air over the pads and debri away from the wheels. If you'd like proof I'd suggest email one of the brake companies, I'm sure they could confirm or deny.

speedracer g37

iTrader: (4)

well rollin, i will agree that people putting drilled or slotted rotor on street cars is purely for looks. i would guarantee that almost 100% percent of these people will never get into a situation that they will max out their braking performance. however, most endurance race cars use drilled or slotted rotors, and as red has said, there must be a reason why.

your idea that it would be cheaper to make rotors with holes in them is faulty. drilled rotors are not cast that way, they are forged, machined, and drilled. also, the smaller mass does heat up faster, but also disipates heat more quickly.