Big Brake Kits vs. PowerStop Brake Kits

[TeeLew]

If cross drilled brake rotors are so stupid, I wonder why they were factory installed on my M5.

So you have to buy more discs and pads for any given usage (street, track, whatever). Go to any pro race and you'll see plently of slotted discs, but you won't see any drilled ones.

The last race car I know of that used drilled discs was the Porsche Cup car from several generations back and those were drilled specifically to be able to sell more parts (it's all spec, there are no alternative suppliers).

 

[Crowd Hunter]

I won't lie. I like how they look, but I will say this. The only aftermarket performance rotors I could find for the M5 are cross drilled too, and I was unwilling to spend $700 per rotor.

https://www.turnermotorsport.com/p-...ksport-wave-rotors-f10-m5-f13-m6-f06-m6-pair/

 

[Firsttexan]

Where do I find these?

EBAY

 

[Radiation Joe]

I believe many people are missing the point that drilled rotors can be quite effective at reducing pad temperatures and gas build-up for a given average rotor temperature. More so, I believe, than slotted rotors. The downside is increased rotor wear and micro cracking. The reason you don't see them on race cars is race cars don't have to have effective brakes at a wide range of temperatures.
I've owned cars with drilled rotors from the factory. I didn't like them. They're noisy. Perhaps BMW puts them on for marketing purposes. I don't know. But I do know that for about the last 10 years or so ///M has stood for Marketing not Motorsport.
As far as Mustangs go, I don't see any advantage to drilled rotors other than aesthetics if you're into that. They are not going to crack at street use temperatures or most light duty track temperatures.

 

[Crowd Hunter]

I've owned cars with drilled rotors from the factory. I didn't like them. They're noisy. Perhaps BMW puts them on for marketing purposes. I don't know.

While I agree that //M is more of a marketing thing that a race thing, I think the real //M cars are still a step above the other BMWs with //M Sport packages slapped on them. I work with a guy who has a hybrid 425i with the //M Performance package, and I still can't figure that out.

As far as drilled and slotted rotors being loud, amen to that. My last BMW had cross drilled and slotted EBC rotors and EBC Yellow Stuff pads, and I loved the sound off the brakes when I got in them. It was like driving a race car all the time.

 

[TeeLew]

I believe many people are missing the point that drilled rotors can be quite effective at reducing pad temperatures and gas build-up for a given average rotor temperature.

Out-gassing really isn't an issue with modern pads. Whatever gain we find in cooling comes at the expense of greater peak temps & larger temp swings due to reduced mass/thermal inertia. The increase in both pad and disc wear is a very real thing. I have seen 'cross-drilled' discs where the holes are just minor divots that are not through holes. I think those are a good alternative.

But I do agree that it looks cool.

 

[Crowd Hunter]

Not for a Mustang, but my new front rotors.

 

[luc]

Not for a Mustang, but my new front rotors.

Why ???
Fashion statement for a BMW maybe?

 

[Crowd Hunter]

Why ???

Because they look so cool.