BMW Performance Rotors

[Eddie135]

Does anyone know if the rear rotors come in drilled and slotted like the front?

[earthconfed]

Yes, I have it installed. They looks the same.

[HIPSI]

Rears are slotted and dimpled.... Still look great though.

[Eddie135]

Originally Posted by earthconfed

Yes, I have it installed. They looks the same.

Strange, all I can find available is dimpled not the drilled ones like the front?

have you got the part number for the performance rear ones?

[Delta Goose]

Originally Posted by Eddie135

Strange, all I can find available is dimpled not the drilled ones like the front?

have you got the part number for the performance rear ones?

I don't believe BMW makes drilled rotors for the rear.

[Dackelone]

The rear BMW Perf rotors only come dimpled and are not drilled. And actually on the new F20/F30 cars the front rotors only come dimpled now. So we are lucky.

[BMW86]

Originally Posted by Dackelone

The rear BMW Perf rotors only come dimpled and are not drilled. And actually on the new F20/F30 cars the front rotors only come dimpled now. So we are lucky.

That's probably because they crack. Mine did.

[Delta Goose]

Originally Posted by BMW86

That's probably because they crack. Mine did.

I just put the performance rotors all around. Is this a common problem? Should I be concerned?

[Dackelone]

Originally Posted by BMW86

That's probably because they crack. Mine did.

IDK... I have had the BMW Perf rotors on my car for almost two years now (@Autobahn warp speeds) and no cracking.

[Eddie135]

I guess dimpled or drilled on the rear ones does not really matters at all.

Because it is BMW Performance labelled and you would expect drilled ones

[BMW86]

Originally Posted by Delta Goose

I just put the performance rotors all around. Is this a common problem? Should I be concerned?

I still got some good use out of them but I've tracked my car and they're not cut out for that. They do look good though. I've replaced the fronts with Stoptech BBK so I'm good now. Rears are still the dimpled Performance rotors.

Originally Posted by Dackelone

IDK... I have had the BMW Perf rotors on my car for almost two years now (@Autobahn warp speeds) and no cracking.


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Nice. But I don't think any rotors would crack from driving at high speeds. Mine seem to have occurred from spirited driving and driving at the track. Mine were only hairline cracks but I know of another local that had pretty bad cracking. It does get pretty warm over here though. You should inspect yours closely to see how they're holding up. I didn't notice mine until a friend pointed it out to me.

[1911A145]

Originally Posted by Dackelone

The rear BMW Perf rotors only come dimpled and are not drilled. And actually on the new F20/F30 cars the front rotors only come dimpled now. So we are lucky.

The old train of thought is that "drilled is better" but across many different performance cars now many auto makers and even after market companies are all switching to and recommending dimpled or just slotted. the drilled holes are more prone to cracking and while they do look awesome on the car they fail almost all the time when you track the car hard.

I have the performance rotors too and after 3-4 weeks the holes are filled up solid with dust anyhow. I have to take a blow gun with a direct tip and get rid of each holes dust pockets. It's a PITA and if I dont the brakes feel very "blah"...

[dsh135]

Being dimpled and not drilled at the back I can live with, and it probably is because of the cracking issue, so that's actually a good thing. What keeps me from buying them is how the slots and holes are all oriented the same direction so that once installed on one side of the car they sweep forward and on the other side they sweep backward. I know that functionally it doesn't make any difference but it makes it seem like these rotors were an afterthought for BMW and/or they just can't be bothered with the additional expense of drilling/cutting the opposite pattern for 50% of the production run. I know that a lot of rotors out there are actually inferior to these, but man, even they don't overlook something as basic as this.

[02rsxpilot]

Brakes rotors are a well researched and documented issue. Bottom line after reading tons of that research: plain old blank rotors offer the best performance. Slotted rotors offer the best combo of looks and performance with the very minor benefit of ability to keep water off the brake surface and keep pads clean (at the cost of increased pad wear). Drilled rotors are for looks but offer the least performance (less surface area) and are prone to cracking.

This is what even the big brake companies say. That being said, if you don't track the car, you're not likely to heat up the rotors enough to cause cracking anyway, so do what you like best!

[BMW86]

You guys are absolutely right. When I replaced my Performance rotors with a Stoptech BBK I made sure I went with slotted non-drilled rotors. I didn't want to make the same mistake twice.

[NORAGRETS]

i have both fronts and rears (rears dimpled). I can say that they stop much quicker than stock rotors, look much better, and the wet-condition braking is much more responsive. plus, I picked up fronts and rears from ECS tuning for like $560 or something like that...well worth it in my opinion. they also have not "grooved" on the fronts like my stock rotors did which is nice

[NORAGRETS]

FYI I dont race/track often. so if thats what you're after, I can say slotted is probably better.

[NORAGRETS]

Originally Posted by 1911A145

The old train of thought is that "drilled is better" but across many different performance cars now many auto makers and even after market companies are all switching to and recommending dimpled or just slotted. the drilled holes are more prone to cracking and while they do look awesome on the car they fail almost all the time when you track the car hard.

I have the performance rotors too and after 3-4 weeks the holes are filled up solid with dust anyhow. I have to take a blow gun with a direct tip and get rid of each holes dust pockets. It's a PITA and if I dont the brakes feel very "blah"...

what kind of pads are you running? i have not had this issue whatsoever...

[1911A145]

Originally Posted by Twhill19

what kind of pads are you running? i have not had this issue whatsoever...

Stock pads. lol

[NORAGRETS]

Originally Posted by 1911A145

Stock pads. lol

soooo when I did pads I did BMW Performance pads...not sure those even exist, or if they are the same as stock. Idk because the dealer managed to cover them under warranty...but I have 0 buildup no rust, no grooving, and no fade thus far.

maybe yours were zinc coated? no clue