Upgrading brake disks - Vagelis
Hi all!

Is there a real benefit in changing the original brake disks with "upgraded" disks of the same diameter? I mean do the extra line patterns and holes make any difference?

I know that patterns are supposed to take the pad-powder away, and holes help cooling down the disk. But do they make a measurable difference?

Having asked some friends, I can't get to a clear conclusion.

Thanks!
Upgrading brake disks - MikeyM
Much opinion around for this one!
The scientific reasons are straight forward. The grooves serve to primarily remove vapour formed when the friction material reaches very high temperatures. Otherwise this can form a cushion between the pad and the disk. Secondary benefits are to remove brake dust and excess water.
There is no measurable benefit to having holes drilled in the disk. It offers no additional cooling other than looking cool! It may serve to offer the above vapour benefits if no grooves are present, but grooves are better! There is engineering evidence to suggest that holes can act as stress points and I have, on cheaper after market disks, seen crazing formed around holes that were just drilled through and not properly chamfered etc.
You get what you pay for, I guess. A well designed, grooved disk made from very high quality material will probably last better, be more resistant to warping and perform slightly better than a standard disk under extreme conditions. Anything designed more for show than performance is less effective than an original manufacturers disk.
Bigger and thicker, as with so many things in life, are where real benefits can be felt. Replacement calipers offering superior rigidity and better heat dissipation are where the big benefits lie. Even the latest brake fluid will vaporise under extreme conditions and taking the heat away from the pads while keeping it from the fluid is as critical as cooling the disks. Pad material is another important area for discussion... but I wont start that one unless someone asks!
 

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