Originally Posted by OC kid
This is a big one that you missed. The stock brake assembly is very heavy. The benefits are multiplied in that it reduces the unsprung weight as well. I will be posting the results after install of the Brembo kit w/ differences in weight. Brembo just took measurements last week and I should have them in before Bimmerfest. TBD.
I'm not so sure. I have not done any weighing of brake components but consider these facts.
-The OEM brake caliper is aluminum.
-The OEM rotors are composite and floating with aluminum hats for less thermal stress and less weight.
-Rotating mass is bad indeed but having sufficient mass in your braking system is crucial for not cooking things.
-BBKs are just that BIG. This means larger and potentially heavier calipers and larger diameter and again potentially (likely) more rotor mass.
I am quite keen to hear about an apples to apples weight comparison of the OEM brakes vs. Brembo.