Are drilled discs dangerous

thexav

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What are your thoughts on Drilled brake discs?

Do they crack more often? What advantages do you get from the drilled holes? Would a grooved disc be better for a road car?
 
Not sure, pretty sure I have had a set of drilled discs on my car once upon a time from EBC if memory serves. All I remember about them was the brake dust generated on my wheels, no issue with the stopping power though.
 
It all about reducing crack inducing design flaws. A classic case in point is the Comet disaster. Planes broke up in flight. Eventually discovered it was due to metal fatigue caused by too tight a radius on the window corners. Redesign of the windows solved this but it was too late and Boeing took over the world.

Holes create stress points. This can be ameliorated to some extent by radiusing the holes each side of the disc. If the discs are vented then you can only radius the outside of the holes. Fewer, bigger holes create less stress points than lots of smaller holes.



On a road car, stick to grooves. If you want holes , make sure they cover the whole area swept by the pad otherwise you will end up with uneven disc wear.
 
It would seem that all METAL/STEEL/CAST IRON discs can develop cracks especially when used hard like track days or for stopping cars/SUV's towing heavy loads/trailers.

I have no experience or info regarding any of the exotic disc materials that one has to take out a second mortgage in order to buy them as to weather
they are prone to cracking when used for extreme braking in racing or track days.


https://www.google.com.au/search?q=drilled+brake+discs+cracking&biw=1615&bih=915&tbm=isch&imgil=GviEe_oTFhZzhM%3A%3BQbhttps://www.google.com.au/search?q=drilled+brake+discs+cracking&biw=1615&bih=915&tbm=isch&imgil=GviEe_oTFhZzhM%3A%3BQb
 
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Interesting Google. I notice that most of the holes are not chamferred and there are cracks in non drilled discs.
 
Is the thinking behind slotted discs to leave channels for gaseous by products of high temperature use or to scrape off pad material to allow a fresh pad surface to be maintained?
 
Thought so ;) I guess that whatever exotic material they are made of makes them resistant to cracks radiating from the drilled holes.??
Do the holes have radius-ed edges?
They're carbon ceramic, and no, the holes don't have radius-ed edges on them at all.
 
the debate has gone on and will continue for years, my 2c worth is, for a road car driven with a bit of attitude slotted is fine, for good looks and if you have nice mags get the drilled, if you want the looks but are worried about cracking look at slotted and dimpled, remembering that reputable brands are normally better than cheap imported stuff. Personally have known of all three to crack under hard sideways usage ;)
 
My 2c worth is that a road car driven swiftly and progressively will work very well with OEM discs, slotted or not. All half decent cars now have ventilated discs front and rear - this is not new. Using OEM discs and pads. If you really need to go further then either change your road driving a bit or buy a different car.
 
My 2c worth is that a road car driven swiftly and progressively will work very well with OEM discs, slotted or not. All half decent cars now have ventilated discs front and rear - this is not new. Using OEM discs and pads. If you really need to go further then either change your road driving a bit or buy a different car.
That's a pathetic answer, the Volvo T5 was under braked from day one, so what you are saying is don't bother modifying your car, just buy a better one?
 
I am assuming that a drilled disc would be heat treated in some way after the drilling and polishing is complete?

That would make sense. I should point out that forging or punching holes will create stress in the metal by process; drilled holes only create stress under use. It is conceivable that annealing after drilling could help the finished part to stand up to such stress, and also help explain the higher cost.

Cocaine is pretty expensive too.

You know I'm willing to wager that there has to be some car out there (Ferrari F-1?, Acura NSX?) that is more expensive per kilo than Cocaine. Market prices usually have reasonable causes.
 

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