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Is there a down-side to using cross drilled discs?
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I've not had cross-drilled discs on any of my cars, but wonder whether the hole edges might accelerate brake pad wear . . .?
 

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Discussion Starter #3
I've not had cross-drilled discs on any of my cars, but wonder whether the hole edges might accelerate brake pad wear . . .?
I had drilled discs on my BMW and Ducati motorcycles with zero problems even when they got red hot. But I still don't know about using them on the RAV4.
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Question is what is the advantage?
 

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Is there a down-side to using cross drilled discs?
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Reduction in surface area. Reduction in thermal mass. Stress risers for crack propagation.

Question is what is the advantage?
In the old days when you stompped on the brakes the pads would heat and the brake pad surface would essentially burn and release a gas. This pocket of trapped gas would negatively affect braking performance. The drilled holes would allow the gas to vent. In conjunction with the cross drilled holes slots were often machined into the rotor. These slots gave a chess grater effect and prevented the pads from glazing.

When one converts a solid rotor to a cross drilled/slotted one they are reducing the braking surface area.

However with modern braking system these points are all trivial. The performance gains equal the negative impacts. People get cross drilled/slotted rotors for looks.
 

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The only practical advantage I've read in car magazines for cross drilled holes in brake discs is increased surface area for heat dissipation.
 

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depends on how you drive, and the quality of the discs... most after market cross drilled rotors are just cheap Chinese discs that have been drilled, and will usually crack with a bit of abuse...

if you do want better cooling on the discs, a good set will keep temps down at the expense or your pads and your wallet...
 

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They also tend to to crack more often. I see no advantage for a street driven car.
 

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They cost more, but I like them. I have a set of drilled and slotted rotors with the ceramic and carbon-fiber pads. They have way more grab than my 225s can hold.
I looked at getting bigger and thicker Toyota brake parts and upgrading my system that way to handle more heat, but that got Very Expensive, Very Fast.

Drilled rotors run cooler and shed heat faster than the stock rotors. The term cross-drilled means that the holes were drilled into the vents instead of the supporting structure. Slotting just uses a small groove that sweeps across pad to venting gas and brake dust, thereby helping to keep a good clean contact.

I like to run high mountain passes for pleasure and I tend to have a lot of stuff in my Rav4, so I ask a lot from my brakes.
I've had this setup for 6 months, and I am very happy with it. I have already had them on passes in Colorado, Utah, Arizona and Wyoming.
 

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They also tend to to crack more often. I see no advantage for a street driven car.
That is news! Where have you seen this?
 

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Yep, cross drilling creates week points, so will crack between the holes. The discs will probably only get hot enough to do it when used hard on a race track though.
 
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