[KGB_123_99]

Just curious...I noticed that Benz loves to put drilled rotors on their C class models in pretty much all but the most basic trim. Any guesses why BMW doesn't do the same?

[Thumper333]

Because drilled rotors are worthless maybe?

They are an appearance gimmick, that's all. If they put them on my cars I would have to accept the added cost of removing them immediately. I actually track my cars and would prefer as much braking performance as I can get.

A while ago Ferrari did some testing, and found that drilled rotors were at best no better than non, and in many cases provided WORSE braking. Porsche came to the same conclusion IIRC. They stopped using them............and their customers bitched up a storm.

They explained that drilled rotors provided no benefits and actually hurt braking performance.....the customers didn't care....because they "looked cool and like a race car.."

The fact that NO RACE TEAM IN THE WORLD runs drilled rotors didn't slow these educated idiots down....and finally capitalism won out and they started giving their customers what they wanted..............even though it was stupid. Afterall, when you are paying $200k for a car you can get pretty much whatever you want.......


Brakes work by exerting force across a surface. Do you know why bigger brakes means better stopping? More surface area, plain and simple. What does drilling dozens of holes in a rotor DO? Yup.....reduces overall surface area. Now sure, if you got really big brakes you are increasing surface area so you might still end up with more stopping power from a drilled BBK over factory brakes.........but going to the same size BBK with normal rotors would be even better.

Drilling came about as some geniuses plan to deal with gas build up from heated pad material. However, modern pads are designed to avoid this problem so drilled rotors are a solution to a problem that doesn't exist.

Now, slotted rotors still have some benefits to cooling, as they increase the surface area that can be used for heat dispersal and can help with glazing by scraping the pads. And if done right the loss of surface area affected is minor as only a small part of the pads will be over slots at the same time. But the same applies, if you "over slot" a rotor you are just removing surface area so that now 20-30% of the pad is over blank space, not rotor face and therefore providing no drag or clamping for brake force.

If anything, we should be asking simply for larger brakes installed from the factory but with standard (or basic slotted) rotors, not drilled rotors that just look cool......after all, BMW is the ultimate driving machine, shouldn't it be about the driving and not the wanna be look?

[ronanz]

Originally Posted by Thumper333

Because drilled rotors are worthless maybe?

They are an appearance gimmick, that's all. If they put them on my cars I would have to accept the added cost of removing them immediately. I actually track my cars and would prefer as much braking performance as I can get.

A while ago Ferrari did some testing, and found that drilled rotors were at best no better than non, and in many cases provided WORSE braking. Porsche came to the same conclusion IIRC. They stopped using them............and their customers bitched up a storm.

They explained that drilled rotors provided no benefits and actually hurt braking performance.....the customers didn't care....because they "looked cool and like a race car.."

The fact that NO RACE TEAM IN THE WORLD runs drilled rotors didn't slow these educated idiots down....and finally capitalism won out and they started giving their customers what they wanted..............even though it was stupid. Afterall, when you are paying $200k for a car you can get pretty much whatever you want.......


Brakes work by exerting force across a surface. Do you know why bigger brakes means better stopping? More surface area, plain and simple. What does drilling dozens of holes in a rotor DO? Yup.....reduces overall surface area. Now sure, if you got really big brakes you are increasing surface area so you might still end up with more stopping power from a drilled BBK over factory brakes.........but going to the same size BBK with normal rotors would be even better.

Drilling came about as some geniuses plan to deal with gas build up from heated pad material. However, modern pads are designed to avoid this problem so drilled rotors are a solution to a problem that doesn't exist.

Now, slotted rotors still have some benefits to cooling, as they increase the surface area that can be used for heat dispersal and can help with glazing by scraping the pads. And if done right the loss of surface area affected is minor as only a small part of the pads will be over slots at the same time. But the same applies, if you "over slot" a rotor you are just removing surface area so that now 20-30% of the pad is over blank space, not rotor face and therefore providing no drag or clamping for brake force.

If anything, we should be asking simply for larger brakes installed from the factory but with standard (or basic slotted) rotors, not drilled rotors that just look cool......after all, BMW is the ultimate driving machine, shouldn't it be about the driving and not the wanna be look?

Hmmmmm....I would've thought it was to redirect cost savings to our non-rattle/squeaking highend interiors.

.

[floydarogers]

Originally Posted by Thumper333

Because drilled rotors are worthless maybe?

They are an appearance gimmick, that's all. ...

++

[CalCarNut]

Mildly slotted and high temp/quality brake fluid/pads will outbrake any silly cross-drilled wannabe setup. +1 on Thumpers explanation.......

[Thumper333]

Originally Posted by ronanz

Hmmmmm....I would've thought it was to redirect cost savings to our non-rattle/squeaking highend interiors.

.

I have H&K.........I hear no squeaks or rattles, I just turn up the DUBSTEP and smile.

[Golden Arrow]

This is a good video to explain the different types of brakes, and why drilled rotors are dumb...which makes them perfect for a Mercedes.

[spuntyb]

Originally Posted by Thumper333

Because drilled rotors are worthless maybe?

They are an appearance gimmick, that's all. If they put them on my cars I would have to accept the added cost of removing them immediately. I actually track my cars and would prefer as much braking performance as I can get.

A while ago Ferrari did some testing, and found that drilled rotors were at best no better than non, and in many cases provided WORSE braking. Porsche came to the same conclusion IIRC. They stopped using them............and their customers bitched up a storm.

They explained that drilled rotors provided no benefits and actually hurt braking performance.....the customers didn't care....because they "looked cool and like a race car.."

The fact that NO RACE TEAM IN THE WORLD runs drilled rotors didn't slow these educated idiots down....and finally capitalism won out and they started giving their customers what they wanted..............even though it was stupid. Afterall, when you are paying $200k for a car you can get pretty much whatever you want.......


Brakes work by exerting force across a surface. Do you know why bigger brakes means better stopping? More surface area, plain and simple. What does drilling dozens of holes in a rotor DO? Yup.....reduces overall surface area. Now sure, if you got really big brakes you are increasing surface area so you might still end up with more stopping power from a drilled BBK over factory brakes.........but going to the same size BBK with normal rotors would be even better.

Drilling came about as some geniuses plan to deal with gas build up from heated pad material. However, modern pads are designed to avoid this problem so drilled rotors are a solution to a problem that doesn't exist.

Now, slotted rotors still have some benefits to cooling, as they increase the surface area that can be used for heat dispersal and can help with glazing by scraping the pads. And if done right the loss of surface area affected is minor as only a small part of the pads will be over slots at the same time. But the same applies, if you "over slot" a rotor you are just removing surface area so that now 20-30% of the pad is over blank space, not rotor face and therefore providing no drag or clamping for brake force.

If anything, we should be asking simply for larger brakes installed from the factory but with standard (or basic slotted) rotors, not drilled rotors that just look cool......after all, BMW is the ultimate driving machine, shouldn't it be about the driving and not the wanna be look?

What he said

[Aaaaaaaaa]

Why no Plastidip from factory either?

[CalCarNut]

Great video ^. Wife's Benz has AMG brakes..and they're drilled. The thing is, every time you change pads on this car you are to change rotors. You can't turn them for another use. Also, because the calipers squeeze the pads so much, it actually will warp the rotors in a pad cycle where it'll vibrate enough to drive you crazy. Great stopping power..but not very durable. Since you toss them out, I don't worry about cracking since they only last ~2yrs at a time...(maybe). That said, I wouldn't use them on any other car given all that's been stated......

[mike@x-ph.com]

Originally Posted by Golden Arrow

This is a good video to explain the different types of brakes, and why drilled rotors are dumb...perfectly fitting for a Mercedes then I suppose.

Thanks for video, very informative

[rolltidef32]

Originally Posted by SoCalDave

Great video ^. Wife's Benz has AMG brakes..and they're drilled. The thing is, every time you change pads on this car you are to change rotors. You can't turn them for another use. Also, because the calipers squeeze the pads so much, it actually will warp the rotors in a pad cycle where it'll vibrate enough to drive you crazy. Great stopping power..but not very durable. Since you toss them out, I don't worry about cracking since they only last ~2yrs at a time...(maybe). That said, I wouldn't use them on any other car given all that's been stated......

Your wife drives with an AMG sport kit; That is so hot! Can't wait until my wife gets her Macan S. Although I think a Porsche with 4 doors is blasphemous, do admit that women driving a properly outfitted Porsche or any sports car is my ultimate turn on.

Well, the Germans don't care about rotors lasting long for good reason. turned rotors diminish braking. If this is on your Camry or Impala, so what, but in a performance automobile where you're likely to "drive spirited", you need all of the stopping power you can get.

Besides, the pads Germans use are good, but usually don't cover the entire surface of the rotor. If you turn them, they'll squeak. On top of this, BMW, Porsche, and Merc say that you're negligent for not following the recommended safe maintenance directions for the brakes.

Thumper, thank you for your wonderful post. We spend a lot of time on this forum education those who "want" but aren't yet. I have no issue with this, since this is what this type of forum is for. Hope some of these guys put aside their pride and egos and just listen. As said before, no racing team uses drilled rotors, they also do nothing for cooling brakes. High temp performance and racing brakes are for taking a beating. If you really are playing with the big boys, thats why there are carbon ceramics.

[KGB_123_99]

Agreed with all the above because it makes sense.

However, the M3 brakes are drilled...looks I guess

[Labeef]

None drilled are the way to go. More surface area equals more stopping power.

[Fronzdan]

Haha, I never could understand how drilled rotors were supposed to be better. Now I know why.

[iconoclast]

dimpled rotors with slots may be the optimal set up. rotors cast with holes in them are stronger than drilled rotors. theoretically they intended to dissipate heat and offer moderate weight savings. as many have stated a lot of the rotors out are drilled and mainly for looks and often have structural issues and will crack.

Originally Posted by pheerix

Why no Plastidip from factory either?

hahaha... i absolutely hate this plastidip fad. it's gross and makes the vehicle look cheap. i would never apply this junk to any of my vehicles.

[Billfitz]

Originally Posted by rolltidef32

Well, the Germans don't care about rotors lasting long for good reason. turned rotors diminish braking.

There's more to it. When I worked in a garage in the early 70s I turned rotors, and you could do so at least three times before they became too thin. One of the changes that's happened since then is that rotors have become much thinner, in part to reduce weight for increased fuel economy. Because they start out thin to begin with they can't be turned as many times before becoming too thin, and in some cases they're so thin initially that they can't be turned at all.

[casualDIYer]

Originally Posted by Thumper333

....

They are an appearance gimmick, that's all.

....

If anything, we should be asking simply for larger brakes installed from the factory but with standard (or basic slotted) rotors, not drilled rotors that just look cool......

++1

Of all the 'mods' one can do to a car this is in the category of 'added negative value'. You spend more money to get less braking. There's plenty of ways to get cool looking brakes without actually decreasing the stopping power including swapping out your calipers or just buying a can of caliper paint.

[chiefneil]

Originally Posted by KGB_123_99

Agreed with all the above because it makes sense.

However, the M3 brakes are drilled...looks I guess

I thought they were dimpled, not drilled?

[Bricktrix]

Originally Posted by chiefneil

I thought they were dimpled, not drilled?

Nope, definitely drilled, was looking up close at one today in dealers.

[rolltidef32]

Originally Posted by Bricktrix

Nope, definitely drilled, was looking up close at one today in dealers.

M3 rotors being drilled wouldn't surprise me, it's a cosmetic enhancement that I'm sure a large number of ///M buyers ask for, for the same reason why other manufacturers offer them; people think they look cool.

Please, lets not fool ourselves into thinking that most ///M buyers are true car enthusiasts looking for the pure driving experience; they aren't.

Difference in ///M buyer to most other BMW owners is that the ///M buyers have more money. This is just like how most who buy a Ferrari aren't true drivers either; they're just rich. A rich guy destroys a nice Ferrari everyday.

Rich guys like to "look" good and cool. Regular guys like to look good too, but other priorities may take precedent.

If you like the drilled rotor look; I get that. Hell, not likely that most ///M drivers will take the car to the track or know how to handle it once there before throwing it into a wall.

Serious track drivers with the coin will opt for carbon ceramics. If not, a BBK with slotted rotors are likely next on the list. All of the rest of us are in it for the looks.

Remember, a car can't make you cool. If you're cool, you just are. Other people will always let you know. Otherwise you're just a lame guy in a nice looking car. You'll know this by how much money you have to spend before a beautiful woman will sleep with you. F.Y.I. the cool guys spend much less.

[CalCarNut]

Originally Posted by rolltidef32

Your wife drives with an AMG sport kit; That is so hot! Can't wait until my wife gets her Macan S. Although I think a Porsche with 4 doors is blasphemous, do admit that women driving a properly outfitted Porsche or any sports car is my ultimate turn on.

Well, the Germans don't care about rotors lasting long for good reason. turned rotors diminish braking. If this is on your Camry or Impala, so what, but in a performance automobile where you're likely to "drive spirited", you need all of the stopping power you can get.

Besides, the pads Germans use are good, but usually don't cover the entire surface of the rotor. If you turn them, they'll squeak. On top of this, BMW, Porsche, and Merc say that you're negligent for not following the recommended safe maintenance directions for the brakes.



Thumper, thank you for your wonderful post. We spend a lot of time on this forum education those who "want" but aren't yet. I have no issue with this, since this is what this type of forum is for. Hope some of these guys put aside their pride and egos and just listen. As said before, no racing team uses drilled rotors, they also do nothing for cooling brakes. High temp performance and racing brakes are for taking a beating. If you really are playing with the big boys, thats why there are carbon ceramics.

and it's a 6MT to boot Roll.

My Impala SS has slotted brake rotors, ATE high temp fluid and carbon metallic pads to whoa 2+ tons down. This is the RWD car, not the lame FWD cars out now . It also has a full HOTCHKIS suspension setup and 285/40s F1s all around. I push this car harder (so far) than my 428i.

We might look at the Macan next year for her. It's a nice rig