[11SEC]

I know most people say to stick with slotted rotors since they don't crack as a drilled rotors, however I notice a lot of high end BBK setups are drilled.

What is the best way to go?

I personally love the drilled look for aesthetics. Wanted to get a drilled/slotted rotor before the winter.

[Manoah]

im a fan of drilled and slotted, mostly for aesthetics though, i also dont do much hard driving.

[ctglass]

R1 Concepts drilled and slotted are the way to go. I don't think they are much of a performance improvement, but damn they look sharp.

Neither.

[11SEC]

Originally Posted by ctglass

R1 Concepts drilled and slotted are the way to go. I don't think they are much of a performance improvement, but damn they look sharp.

It sure should help with cooling

[ctglass]

Originally Posted by 11SEC

It sure should help with cooling

You would have to track your car pretty hard for that, but yes. These rotors are great and would sure help with a track day. But I got them for my DD just for the looks

[The HACK]

Drilling and slotting does NOTHING for performance. For hard driven, tracked rotors, blanks are the best.

Now, you're probably going to ask, then why are [insert race team/series/whatever...I'll even bite, F1] rotors slotted/drilled/whatever...The first thing I am going to say to that is, do you race in [insert race team/series/whatever, maybe even F1]? If you do you probably wouldn't be asking this question in the first place. But since you don't...

Most race teams with a big budget won't care about the fact that drilled rotors offer little performance benefit. They drill their rotor now-a-days to SAVE WEIGHT. Especially in the upper echelon of racing in the professional levels, every ounce saved off of a rotating unsprung mass can mean another 1/100th of a second in a hot flying qualifying lap, and that difference can mean multiple spots on the grid. When your operating budget is on the orders of $600M plus per year, you do whatever you can to find that last bit of "performance," with little to no regard to actual real-life longevity. Most rotors at this level of competition are used and abused and thrown away after 1 race.

Notice I didn't say anything about slotted above. Slotting a rotor offers certain performance benefits. Slotting removes a small amount of material off of the rotor surface. The slots provide a "grating" surface to keep the pad material fresh. In high performance applications, when pads heat up, the dust from the pads will re-bind to the pad surface, making it "glaze" over into a very smooth surface resulting in significantly reduced friction. You don't want that while trying to brake from 100+ mph to 35mph repeatedly, 2-3 times every couple of minutes. A slotted rotor will scrape away a small amount of the pad surface every time you brake.

The end result, is your pad life will be shortened, you'll introduce a lot more noise and vibration every time you brake, and you'll generate a lot more dust with drilled and/or slotted rotors. Do they perform better on track? Not significantly, not over blank rotors. The breaks in the surface from drilled or slots, drilled in particular, are prone to cracks because those areas expand and contract at different rate than the rest of the rotor. The rapid expanding and contracting results in dramatically shortened rotor life in high performance applications, especially for drilled rotors since those area tend to be significantly weaker than the solid portion of the rotor.

Again, you're going to ask...I just know it, well why then does BMW include drilled rotors on their M cars? Why does high end sports cars come with drilled rotors? It's called MARKETING. Long, LONG time ago...Back in the golden age of racing where men faced DEATH every time they step onto the hot side of the pit, brake pad materials are bonded with an agent that disintegrate and OUTGAS as it heats up while racing. That hot gas forms a layer between the pads and the rotor, reducing brake efficiency. So they started drilling holes in the rotors to allow that hot air to escape, thus allowing the pads to come in full contact with the rotor again.

Brake pad bonding agent haven't had to "outgas" for decades, not with newer bonding agent and high temp ovens baking the pad material together. But since the 50s and 60s drilled rotors have been associated with high performance race cars, and that mis-conception continued and remain pervasive until today, since car companies have bought into the idea that they can sell their cars with drilled rotors to denote "high performance" or "race engineering" when the opposite is true. It is all about marketing, since it cost them the same to make the car with or without drilled rotors, but they can charge MORE for a car that comes with drilled rotors. Well, that mis-conception compounds upon itself, and now-a-days if you try to sell a high performance vehicle without drilled rotors? It gets lumped in with the rest of the pedestrian transportation appliances, and people ask, "why doesn't my [insert performance model] come with drilled rotors?"

As if drilled rotors mean performance.

So, you're probably going to ask..."Hey dumb@ss, you said drilled and slotted does nothing for performance. Well, you just listed a bunch of benefits in your long winded dissertation for drilled and slotted rotors!" Yeah, I did. I listed a bunch of performance benefits for cars that are near the upper echelon of racing, where longevity and daily use isn't a part of the usage equation. Drilled and slotted rotors will do you absolutely NO GOOD when it comes to a car that gets driven daily on the street, and never EVER sniff the hot side of a pit lane. And even if it does sniff the hot side of the pit lane, it still offer very little tangible benefit, and the benefit certainly does not outweigh the detriment...The increased pad wear, the increased pad dusting, increased noise, vibration, and harshness, the increased likelihood of stress damage and cracks formed...etc. And if your car sniffs the hot side of the pit lane REGULARLY, then yeah, slotted rotors can offer some real benefits...But at that point, you're probably not going to be looking at simple OE fitment that has drilled or slotted patterns. You should be looking for a good 2 piece FLOATING rotor as your priority, not the drilled/slotted feature...And if you are still looking for drilled or slotted, relative few 2 piece floating rotor comes without one or the other (or both).

But if your primary concern is that your brakes must look good...Well, I can't deny that a set of drilled or slotted rotor does attract the hunnies like a pimp suit and a fedora. That, in and of itself, is the best PERFORMANCE that drilled and slotted rotors can offer.

[The HACK]

Originally Posted by 11SEC

It sure should help with cooling

No it doesn't.

[Miller335]

I believe the higher drilled rotors are not really drilled.
They are cast with the holes, not drilled in after the fact.

[mike-y]

I knew a guy that had a BB kit on his integra years ago with drilled rotors, after 3 rotors cracked during lapping days, he swapped to blanks.

even if you look at a lot of modern indy/F1 cars, most don't use drilled rotors:

[TheSt|G]

Originally Posted by The HACK

Drilling and slotting does NOTHING for performance. For hard driven, tracked rotors, blanks are the best.

Now, you're probably going to ask, then why are [insert race team/series/whatever...I'll even bite, F1] rotors slotted/drilled/whatever...The first thing I am going to say to that is, do you race in [insert race team/series/whatever, maybe even F1]? If you do you probably wouldn't be asking this question in the first place. But since you don't...

Most race teams with a big budget won't care about the fact that drilled rotors offer little performance benefit. They drill their rotor now-a-days to SAVE WEIGHT. Especially in the upper echelon of racing in the professional levels, every ounce saved off of a rotating unsprung mass can mean another 1/100th of a second in a hot flying qualifying lap, and that difference can mean multiple spots on the grid. When your operating budget is on the orders of $600M plus per year, you do whatever you can to find that last bit of "performance," with little to no regard to actual real-life longevity. Most rotors at this level of competition are used and abused and thrown away after 1 race.

Notice I didn't say anything about slotted above. Slotting a rotor offers certain performance benefits. Slotting removes a small amount of material off of the rotor surface. The slots provide a "grating" surface to keep the pad material fresh. In high performance applications, when pads heat up, the dust from the pads will re-bind to the pad surface, making it "glaze" over into a very smooth surface resulting in significantly reduced friction. You don't want that while trying to brake from 100+ mph to 35mph repeatedly, 2-3 times every couple of minutes. A slotted rotor will scrape away a small amount of the pad surface every time you brake.

The end result, is your pad life will be shortened, you'll introduce a lot more noise and vibration every time you brake, and you'll generate a lot more dust with drilled and/or slotted rotors. Do they perform better on track? Not significantly, not over blank rotors. The breaks in the surface from drilled or slots, drilled in particular, are prone to cracks because those areas expand and contract at different rate than the rest of the rotor. The rapid expanding and contracting results in dramatically shortened rotor life in high performance applications, especially for drilled rotors since those area tend to be significantly weaker than the solid portion of the rotor.

Again, you're going to ask...I just know it, well why then does BMW include drilled rotors on their M cars? Why does high end sports cars come with drilled rotors? It's called MARKETING. Long, LONG time ago...Back in the golden age of racing where men faced DEATH every time they step onto the hot side of the pit, brake pad materials are bonded with an agent that disintegrate and OUTGAS as it heats up while racing. That hot gas forms a layer between the pads and the rotor, reducing brake efficiency. So they started drilling holes in the rotors to allow that hot air to escape, thus allowing the pads to come in full contact with the rotor again.

Brake pad bonding agent haven't had to "outgas" for decades, not with newer bonding agent and high temp ovens baking the pad material together. But since the 50s and 60s drilled rotors have been associated with high performance race cars, and that mis-conception continued and remain pervasive until today, since car companies have bought into the idea that they can sell their cars with drilled rotors to denote "high performance" or "race engineering" when the opposite is true. It is all about marketing, since it cost them the same to make the car with or without drilled rotors, but they can charge MORE for a car that comes with drilled rotors. Well, that mis-conception compounds upon itself, and now-a-days if you try to sell a high performance vehicle without drilled rotors? It gets lumped in with the rest of the pedestrian transportation appliances, and people ask, "why doesn't my [insert performance model] come with drilled rotors?"

As if drilled rotors mean performance.

So, you're probably going to ask..."Hey dumb@ss, you said drilled and slotted does nothing for performance. Well, you just listed a bunch of benefits in your long winded dissertation for drilled and slotted rotors!" Yeah, I did. I listed a bunch of performance benefits for cars that are near the upper echelon of racing, where longevity and daily use isn't a part of the usage equation. Drilled and slotted rotors will do you absolutely NO GOOD when it comes to a car that gets driven daily on the street, and never EVER sniff the hot side of a pit lane. And even if it does sniff the hot side of the pit lane, it still offer very little tangible benefit, and the benefit certainly does not outweigh the detriment...The increased pad wear, the increased pad dusting, increased noise, vibration, and harshness, the increased likelihood of stress damage and cracks formed...etc. And if your car sniffs the hot side of the pit lane REGULARLY, then yeah, slotted rotors can offer some real benefits...But at that point, you're probably not going to be looking at simple OE fitment that has drilled or slotted patterns. You should be looking for a good 2 piece FLOATING rotor as your priority, not the drilled/slotted feature...And if you are still looking for drilled or slotted, relative few 2 piece floating rotor comes without one or the other (or both).

But if your primary concern is that your brakes must look good...Well, I can't deny that a set of drilled or slotted rotor does attract the hunnies like a pimp suit and a fedora. That, in and of itself, is the best PERFORMANCE that drilled and slotted rotors can offer.

Oh I love a well reasoned rant.

[11SEC]

Thank you!!!! Blanks it is!!

Anyone recommend a good blank 2piece floating rotor?

[11SEC]

The only brand I can find that has front and rear is Racing Brake at $1800 for front and rear.....pretty pricey. Must be a serious upgrade.

[TheSt|G]

What's the application/duty cycle anticipated?

[JoeyH335i]

Wow! I am surprised that not all the F1 cars don't have the calipers on the bottom of the rotor to help keep the wieght lower to the ground...

Originally Posted by mike-y

I knew a guy that had a BB kit on his integra years ago with drilled rotors, after 3 rotors cracked during lapping days, he swapped to blanks.

even if you look at a lot of modern indy/F1 cars, most don't use drilled rotors:

[mweisdorfer]

Unless you are tracking your car, having cross drills and slotted rotors is "tim the tool man Taylor"

They will look cool no doubt, but that's about it.

Cost wise your way better off getting brembo rotors and Akebono pads.

Originally Posted by 11SEC

Thank you!!!! Blanks it is!!

Anyone recommend a good blank 2piece floating rotor?

An OEM version of the Z4 front rotors are 2 piece.

[The HACK]

Originally Posted by FCobra94

An OEM version of the Z4 front rotors are 2 piece.

The Z4 rotors may be 2 piece, but they're not floating rotors. Floating rotors has the rings of the rotors that moves "freely" upon expansion from the hub of the rotor. The OEM rotors on E46 CSL/ZCP package, the OEM rotors on the E9X M3, and the E85/E86 MZ4s are floating 2 piece rotors. The rotors from the E89 Z4, E6x 545i/550i, E6x 645i/650i are 2 piece (sometimes 3) but the rotors and part of the hub is cast together therefore they do not offer any significant advantage except it saves a little bit of weight from the part of the rotor closest to the center of rotation.

[The HACK]

Originally Posted by JoeyH335i

Wow! I am surprised that not all the F1 cars don't have the calipers on the bottom of the rotor to help keep the wieght lower to the ground...

Probably because those calipers are feathery light compared to the whole brake system.

[135Pats]

Blanks or slotted. As noted drilled offers absolutely nothing on a street driven car.

[11SEC]

Originally Posted by The HACK

The Z4 rotors may be 2 piece, but they're not floating rotors. Floating rotors has the rings of the rotors that moves "freely" upon expansion from the hub of the rotor. The OEM rotors on E46 CSL/ZCP package, the OEM rotors on the E9X M3, and the E85/E86 MZ4s are floating 2 piece rotors. The rotors from the E89 Z4, E6x 545i/550i, E6x 645i/650i are 2 piece (sometimes 3) but the rotors and part of the hub is cast together therefore they do not offer any significant advantage except it saves a little bit of weight from the part of the rotor closest to the center of rotation.

Are any of the above a direct fitment for our e9x?

[The HACK]

If they are, you're paying extra for very little gain IMO. The 2 piece rotor on my dad's 545i is almost as expensive as the TRUE floating 2 piece rotors that are OEM in my MZ4.