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My Stage 4 brake kit uses Mercedes rotors because they are the only off-the-shelf part deep enough to keep the fat calipers away from the spokes of a commonly available/reasonably priced wheel.

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I disagree;
I have run the "cheap" drilled rotors for many years on many different cars with no issues.By "cheap" I mean the auto store replacement rotors that some one has drilled in their shop.
Yes I agree the serve no purpose other than look cool, yes less material means less heat disapation, and yes more surface area the greater possibility of crack nuclation.... However on the street these are vary minor inefficiencys. Even in autocross events your brakes donot get hot enough for any of this to make a difference. I have found that the pads wear excessively and the rotors start to develop un-even wear long before any material fatigue can take place..... And that's on a daily driver; so these issues will be even less evident on a "good weather" car.
The quickest I have ever had a set fail was on a modern silverado I drove daily and hauled many cars/parts with. I went thru a set of ebay drilled rotors in 10k miles. Even then I blame the ceramic pads more than I do the rotors.

IMO if you like how the look go for it, if you are trying to build a "race car" you are never going to get there with ebay parts, so stop being cheap.

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Drilled rotors are fine for the street and autocross because you don't build up heat as high when compared to driving a track day at a road course. Driving repeat extended hard laps at a road course will crack any cast iron rotor eventually, drilled or not.

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Are you inferring its the elevated temps that mainly causes the cracking cracking issue? Because I thought that cracking was related more to varying and repeated temp changes, not the ultimate temp, and if that is true, seems like street use would have more and wider temp changes then a closed circuit race track use. I'm not sure of the temp swings.

I would think most would agree a drilled rotor would crack easier then a solid rotor, and most will agreed a failed rotor when being driven/used is kinda bad, where we agree to disagree and reagree is how likely that is to happen and how much risk one is comfortable with assuming that risk.

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Are you inferring its the elevated temps that mainly causes the cracking cracking issue? Because I thought that cracking was related more to varying and repeated temp changes, not the ultimate temp, and if that is true, seems like street use would have more and wider temp changes then a closed circuit race track use. I'm not sure of the temp swings.

I would think most would agree a drilled rotor would crack easier then a solid rotor, and most will agreed a failed rotor when being driven/used is kinda bad, where we agree to disagree and reagree is how likely that is to happen and how much risk one is comfortable with assuming that risk.

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Probably? What the heck do I know?

I drive a 40 year old Plymouth...
I'm not that smart,
haha!

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Holes in pretty much anything are evil stress risers, avoid them.

I know of a set of drilled rotors that didn't even make it 10k miles before cracking. Yeah, they were home drilled about 20 years ago. Don't care, no drilled for me. Those that want them know that I'm laughing at your ignorance.

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Now I'm laughing at your ignorance.

Holes cast into the rotor during manufacturing do not promote stress fractures.
Holes drilled into rotors after casting will lead to fractures.

That's been proven through the years.

The holes provide limited outgassing, reduce weight, and save raw materials. They also look sporty to some people. That's why they get used.

Sometimes performance oriented auto manufacturers investigate things a wee bit more thoroughly than internet keyboard warriors.

















Now, would you like to revise that statement?

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I think we are splitting hairs here, a hole, drilled or cast, is a stress riser compared to no hole, period.

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The king of splitting hairs comments about others splitting hairs?






Obviously, rotors with holes are inferior to non-holed rotors. That's why you'll never see them on supercars costing hundreds of thousands of dollars.




OOPS!! I misspoke. That car cost a couple million dollars, runs 250+ mph, and has zero engineering behind it.
Stupid VW! What were they thinking?