Re: Cayenne Question
Hey Ron (Houston),
I am not an expert but I do have an engineering background so here is my stab at it. I think it has to do with the Cayenne having the ability to go off road. Often rocks and dirt can get impacted in the holes and when the brake pad comes along on the rotor across its face and hits the stuff it is not good for neither rotor or pad. That is the only thing I can think of. Anyone else got any insight.
But I do not think the holes are really that necessary for the Cayenne anyway. On the 911s and Boxster S cars, the only purpose the holes serve is to a) allow release of hot metal gas from between the pad and rotor which causes brake fade, b) better cooling of the rotor from extreme use like the race track (which capable the Cayenne might be I doubt most Cayenne owners will race their Cayennes but they might take it out on track days) and c) allow the build up of steam that is caused by friction between the rotor and pad in the wet to be released which causes brake fade. And anyway with 18-inch brake rotors front (5 inches larger than the Turbo brakes!) and 17 inch brake rotors rear (4 inches larger than the Turbo brakes!), the Cayenne will have no trouble stopping. If this is true and the Cayenne has 18 inch front rotors, this simply dwarfs the BMW 4.6is front brakes which are 14.6 inches. WOW!
Yes my friends, the Cayenne will plaster the whole family on the front windshield if daddy hits the brakes in an emergency stop.