Quote Originally Posted by keldsyke View Post
Ok, you are confusing efficiency with the force a brake caliper / drum set up can put out, if you think a drum brake has one cylinder with two small bores which act against the brake shoes which contact the drum, a brake caliper (performance caliper) usually has four pistons (can be up to 10) with diameters of anything from 25mm to 40mm so the caliper can put 4 x pistons onto the pad which contacts the disc , where a drum set up will put 2 x small bore pistons which will give a smaller braking torque. Where the caliper falls down is that it’s not very energy efficient where the heat will either go into the disc or atmosphere whereas the drum set up retains the heat in the drum. (Hence why the F1 cars use a drum over the caliper and disc) Drum technology has moved on and most military stuff uses drums as the actuation side and amount of force that can be acted on a drum has come on. All motorsport is about is energy management and controlling it to a certain degree.

Regen systems has taken a completely different turn as now with regenning through a motor you can down spec calipers / discs (lighter reducing un sprung mass, which is great for handling and performance) as the most braking force you are going to need is when the battery is full as when the battery uses power the regenthrough the motor will take up the difference in braking force needed and the calipers / discs taking up the rest of the force needed.

Formula E this season decided to take away the rear brakes completely and just rely on Regen on the rear axle but this ended in disaster as if you have no Regen on the first few laps (battery fully charged) and no conventional brakes then you’re not going to stop!! They’ve now reverted to re-fitting rear brakes!! Hope this explains!
"If you ask me, Muhammad Ali, in his prime, was much better than anti-lock brakes."