Rotors: Stock vs Slotted vs Drilled vs Slotted/Drilled

[m pwrd 3]

Ok so I am starting to price some rotors for a winter brake upgrade. I have read soooooo many arguments on which design is the best. Could someone here please shine some light on the matter from experience or research. Keep in mind I know a oversized rotor and bigger calipers are the best up grade, but I am not going to go that route unless I find a deal. Anyway debate away.


Thanks

[Feedman]

You are going to hear that cross drilling causes them to crack. I have had 2 different sets and this has happened a total of ZERO times. Stoppping difference was drasticly reduced.

Mine are drilled/slotted brembo blanks with some good pads and you can't go wrong...

Good luck.... 8)

[RobbieNelson]

You are going to hear that cross drilling causes them to crack. I have had 2 different sets and this has happened a total of ZERO times. Stoppping difference was drasticly reduced.

Mine are drilled/slotted brembo blanks with some good pads and you can't go wrong...

Good luck.... 8)

But.... I can't imagine that you're that hard on a set of rotors. If you have plans to take the car to a track, you'd be more likely to crack a set of drilled rotors.

[Davis Silver Sti]

I would consider the quality of the slotted/drilled rotors first. If you buy the base grade, you can expect a lower quality and potential problems if you get the rotors heated up. Just not worth it in my opinion as this is a crucial part of the car. I'd only go cross drilled and slotted if I had had a $$ budget to work with. ($2000+)

As you already know BMW stuff is rather $$. I'd rather go with either the stock type of normal (non-slotted/drilled) rotors or a step up on some higher quality normal rotors.

Get some rotor friendly brake pads. I've been very happy with my CarboTech Bobcat pads. (50% less dust!) Great performance and you can really pound on them all day with confidence.

I have 10 AutoXs, and 2 HPDE on my stock rotors (12.7 inchers front). They are doing fine but I will probably get another set next year just in case. If you are going to do any track events, brake pads upgrade and hi-temp fluids is a must. Track events really put the pressure on your brakes. It is not fun going around a track at speed if you do not have full confidence in your brakes. I boiled my brakes at Mid-Ohio....I shoulda changed fluids and pads before I went. (lesson learned) Put more emphasis on pads, fluids, lines than rotors at this time unless you get really serious.


Sure Lamborghini, Ferrari and Porsche have slotted/drilled rotors BUT the quality of their braking system is very high. Like I said above, I'd stick to normal rotors and beef up the pads, lines and fluids unless you have a high budget for your braking system and are planning to do lots of track events.
Just my .03

[Davis Silver Sti]

You are going to hear that cross drilling causes them to crack. I have had 2 different sets and this has happened a total of ZERO times. Stoppping difference was drasticly reduced.

Mine are drilled/slotted brembo blanks with some good pads and you can't go wrong...

Good luck.... 8)

But.... I can't imagine that you're that hard on a set of rotors. If you have plans to take the car to a track, you'd be more likely to crack a set of drilled rotors.

YEP!

[RobbieNelson]

Stoppping difference was drasticly reduced.

Perforations in rotors, be it drilled holes or slots, are there to help get rid of vaporized pad material, not to increase braking force. When pads get super heated some of the pad material will vaporize causing a layer of gas to form between the rotor and pad. This can cause "brake fade". If you don't change your brake fluid often and switch to a high temp fluid, you're more likely to experience brake fade due to boiled fluid than vaporized pad material.

Why change brake fluid? It absorbs water and water boils at a much lower temperature than the brake fluid. Air/water vapor in a hydraulic system is not a good thing!

[daveb91]

Try better pads Dot3 or 4 fluid and if you dont have them stainless steal brake lines.

[Davis Silver Sti]

You are going to hear that cross drilling causes them to crack. I have had 2 different sets and this has happened a total of ZERO times. Stoppping difference was drasticly reduced.

Mine are drilled/slotted brembo blanks with some good pads and you can't go wrong...

Good luck.... 8)

Question.

Were your rotors drilled and slotted from the factory or were they blanks and then somebody (perhaps an aftermarket copany) drilled and slotted them later? Just curious.

[m pwrd 3]

Well I have already planned on:

Ate super blue brake fluid - said to be among the best
UUC Stainless lines
and Hawk HP or HPS pads - these seem to be popular among BMW people

When putting all this in I just wanted new rotors to complete the package you might say. I didnt want to have everything else new and the rotors be my weak point.

So blank rotors seem to be the choice -- Do you think I should go with OEM or Brembo Blanks or do you guys know of any other options?

[Feedman]

You are going to hear that cross drilling causes them to crack. I have had 2 different sets and this has happened a total of ZERO times. Stoppping difference was drasticly reduced.

Mine are drilled/slotted brembo blanks with some good pads and you can't go wrong...

Good luck.... 8)

But.... I can't imagine that you're that hard on a set of rotors. If you have plans to take the car to a track, you'd be more likely to crack a set of drilled rotors.

You are correcto, I haven't seen any "track" days. But I am surely put them through there paces..... Do you forget who you are talking to....I had them on for several years with no problem whatsover.

Davis to answer your question, they were brembo blanks that were machined slotted and cross drilled.....

As far as the experience, I have had several people drive my car, before and after, some didn't even know I had the new rotors and mentioned to me that they felt my car "stopped" better....so go figure. I know I drove more aggressively after the rotors were on my car. Although I had better pads too.....??

This is striclty my experience.... 8)

[narfdanarf]

I was scared to drive his car when he first got it cause the brakes sucked so bad, then when he got his new rotors they stop like whoa....maybe his old rotors were just glazed over or something, butt in any event they are better now :!: