Originally Posted by Richbot
Just the facts ma'am:
E46 M3 at 3500lbs with driver braking from 135 mph for a 60 mph corner needs to dissipate approximately 550kcal of kinetic energy. E92 M3 braking from 145mph for the same corner needs to dissipate approximately 705kcal of kinetic energy. That's a ~7% increase in weight and speed and ~45% increase in heat load on the brakes. The E92 brakes are bigger but they aren't 45% bigger, and at bigger tracks the speed gap is even more significant. Faster cars are harder on equipment, k=mv^2. BMW had a choice to provide everything from a setup for a 150mph car with a sensitive driver to manage on track to one that can throw down qualifying laps for a whole race distance on a 100 degree day running 6" from another car's bumper. One is what we have from the factory, the other would probably need to be water cooled to fit under 18" wheels.
You're defending the well known position that the E9X brakes are not nearly as capable as the earlier cars. I'm trying to help get some more cooling to them with at least the same method as the earlier cars.