Not trying to stir the pot

[Chevyman73]

I agree that both are more for show than function. Since most brake pads come with at least a single slot in them to provide some degree of relief for outgasing wether it's really need or not. I have plain C5 rotors for my Camaro and they won't recieve any type of slotting or drilling. If it were necessary though I would still rather have it slotted instead of crossdrilled though. But Baer does say "Ironically more pedestrian pads used on most streetcars will still exhibit ‘outgassing’, but only when used at temperatures normally only encountered on the racetrack".

[nancejd]

First let me say I really don't know what the answer is, but aren't we really talking about street pads being used at race car speeds? That's what the C6 is designed for too. I don't think most of our cars are going to be running race pads on the street, some will, but most won't. So if you are running a street pad, would there be a benefit to cross drilling or slotting? Or is it worthless in that application too?

[dennis68]

Nothing about the C6 pad is street use. If you call the dealer in the morning the lowest grade pad they sell for any Corvette since the C5 was introduced is a ceramic pad. Bare is talking about true street pads, like Kragen 39.00 specials, being used on the track. Not more or less track pads that get used on the street.

[yody]

actually i doubt that the C6 uses "race" pads. A true race pad needs to be cycled and heated up before it works effectively, and i doubt that GM could sell many corvettes if they told the owners that there brakes won't work effectively if they don't heat them up first! Also since you claim that
"another old racer technique (that isn't used anymore) turned into "bling" for the bolt on crowd." I guess Ferrari and Mercedes and Corvettes use them because they are still using old race techonology. And that Porsche engineers just merely are bolt on bling bling type of guys. Sorry Dennis i think youve been hanging around CC.com too much

[Flyboy]

And that Porsche engineers just merely are bolt on bling bling type of guys.

They're not?

[baz67]

I promise I did not want to stir it up. We all agree that the brake system as a whole is one of the if not the most important safety system on our cars. Why would we put a part on them that has proven to fail. This is not just theory or assumtion. The thread from the old board had a few pics of cracked rotors. Now I am all for saving unsprung weight were I can, but I WILL NOT do it at the expence of safety. Even if it is a remote chance of the part failing. Remember Murphy's law. I will find better ways to save a pound or two.

As for why some other high end cars use them, all I can say if form over function. The typical buyers of these autos do not know the differance between a drilled rotor and thier... well you know. No the engineers are not the bling type, but the people trying to sell them are. I think the marketing department won on that.

There have been some studies on this and some will question them. However they all point to drilling rotors to be a neglegable benefit with todays pad compounds. Even if the testing was not perfect, it does point in that direction. That can not be discounted. We have some smart knowlegable people on this site. Why all of them have not chimed in is anyones guess. Maybe they do not know or just want to keep it a secret and watch us argue the point.

Brian

[dennis68]

Yodi, FYI-ALL brake pads are supposed to heat cycled. Most owners just don't want to go through the hassle of doing it correct. And yes, Mercedes, Porsche, and however else are in it for the "bling" factor. Go to any high dealer (I work at one) and watch customers about potential purchases, they do climb around and questions like "why do the brakes have holes" and salesman answer "because they are high performance brakes". "Bling" sells cars.

Brian, the others you speak of had this argument so many times they are probably tired of it. It is tough to explain why something doesn't work when the biggest argument coming back is "well, so and so company sells them, or Mr. Bigshot car manufacture puts them on their cars". Mr. Bigshot cars also puts airbags and ABS on their cars, I don't suppose you want to retrofit your classics with those do you?

[yody]

Dennis not to step on your toes or anyting and maybe i am wrong but i think there is a BIg difference between a chrysler customer and a Porshce/Ferrari customer, Also are you trying to tell me that Porsche and others are putting brakes on their car because stupid people will think its cool when the salesman tells them they brake better? I think that most people shopping for those cars already assume that the car is a top of the line sportscar and will stop pretty darn good, holes or not! Also the high end companies know that a majority of the owners will be occasionaly racing their cars, and what about people who drive on the autobahn? I don't have any answeres but i am not going to base my decision on a company that sells brake kits and a bunch of smart jerks on a website. But as i stated before i think they look cool, and since i haven't tried them before i will give them a go and see what happens.

[dennis68]

Actually I was talking about the Mercedes cutomers and Lincoln customers, I work on Chrysler's but work at a Lincoln dealer and have worked at the Automall in Fremont (Porshce, Mercedes). How may snotty doctors do you think actually race their cars. I'll bet less than 2% of all new Porshce customers ever race thier cars.

[yody]

valid point about porsche owners! Everyone in Marin drives a porsche, most of them probably haven't even taken the engine past 3000Rpm! One thing about porsches is that they have a lot of racing teams and are succesfull in many different competitions, companies like that have tons of R+D with some of the top engineers. I trust their R+D and their engineers over a "kit" company or people chatting on line any day, look at Ferrrari, they even have drilled rotors on teh enzo, although it looks lke they are using Ceramic rotors! So if ceramic doesn't need venting then why does their ceramic rotors have holes. It just doesn't make sense. And saying that the only reason Ferrari puts drilled rotors on their top of the line million dollar super car is because the people who buy them will be tricked into it just doesnt fly with me, especially since they sell themselves! Also if venting brake gasses is an old trick from long ago, then why do many Nascar cars run slotted rotors? and why do people say that drilled rotors aren't good but slots are but that you don't really need to vent new brakes?? sounds like a bunch of hipocracy and no one really knows what they are talking about including me.

[dennis68]

We know Cody, I'll just leave it that. You go ahead and continue to beleive that if Ferarri does it then it must be the thing to do.

[Fuelie Fan]

the force required to accell/decell an object rises exponentialy with speed and/or weight,not linearaly.it takes far more than twice the force to affect a mass that is twice as heavy.a motorcycle's rotors are much more exposed to cooling airflow.back in the day we would drag the front brake a bit towards the end of long straights to build heat before the brake zone.drilled rotors on motorcycles may be more for unsprung mass reduction.unsprung weight is most important as it compares to sprung weight.a couple ounces is a bigger percentage of the total on a lighter vehicle.as far a the c6 it probably has ac and leather seats-and that isn't to make it faster either.

An objects energy does rise linearly with respect to mass, but quadratic with respect to speed (KE = 1/2 m*v^2). Therefore, brake sizing for energy dissipation would be much more strongly tied to a vehicle's top speed than to it's mass.

I don't think anybody was saying motorcycles have different laws of physics. The point was that motorcycles have completely different design criteria becuase the positioning of the rotors in freestream air means one can expect completely different heat transfer rates TO that surrounding air, which is really the limiting factor to rotor mass determination. This is why they don't need huge vaned rotors. It is probably also why they can swiss cheese the heck out of them for weight savings. Recall: Ffk (force of kinetic friction) = mu_k (coef of kinetic friction) * Fn (normal force). There is no area requirement. Removing surface area therefore does not reduce available braking torque.

I don't pretend to have any answer as to whether drilled rotors actually increase braking potential, what the effects of different pad materials are, outgassing, etc. All I know is I've seen a few pics of cracked rotors, I don't really want "the look" that bad, I don't need the few hundred grams of weight savings, and based on that reasoning I plan to use undrilled rotors.

[yody]

Dennis is it me, or do i just love poking you in the ribs?

[dennis68]

It's you.

[baz67]

I don't pretend to have any answer as to whether drilled rotors actually increase braking potential, what the effects of different pad materials are, outgassing, etc. All I know is I've seen a few pics of cracked rotors, I don't really want "the look" that bad, I don't need the few hundred grams of weight savings, and based on that reasoning I plan to use undrilled rotors.

Well said. I guess that was the point I was trying to make. Man and I was not trying to start any fires.
Brian

[yody]

hey dennis, wasn't your car a nice white before?

[dennis68]

[baz67]

Ok after many hours doing more research the answer may be.... Wet Rotors. It seams that some other high end German sports car manufacture mentioned earlier states that the holes help let water vapor or steam escape. That kind of makes sense to me. They were testing in Gemany. I guess we will see if the production version has them.
Brian

[StRacerDuke]

My personal choice in brakes would be the drilled and double slotted stainless brake lines. I hear they work great on the track.

[David Pozzi]

Everyone doing ok here?
Just checking...
David