Well, "optimum braking" occurs for a shorter time and distance based on my current set v std m sport setup.
Bigger disc diameter means vented slots on circumference of discs is moving faster through the air increasing the cooling effect. Extra leverage from large discs means that brake force is increased for same pressure applied....
As far as air ducts, I noticed that LCI M135i doesn't have the open ducts as per Pre LCI so not sure if or how you can remove blanking plates from inner wheelarch liner - as per thread below - works on the LCI cars ?
http://www.babybmw.net/forum/viewtop...=ducts#p775132
