Typically you can still improve your brake's heat dissipation through rotors more effectively than through the calipers though, especially if the rotors are vented. And unless ducting is not allowed, I still would stick to using the rotor as your heat sink rather than the calipers.

 

That's true but sometimes there's only so much heat dissipation/mass available. Having racing ITS 240s with two 3" ducts to each solid front brake rotor, we still saw rotor temps over 1,300 degrees and caliper temps over 875 degrees. Machining custom stainless and titanium caliper pistons helped keep some of that temp away from the fluid, for a while. But during a 6 hour enduro in July at Buttonwillow, everything heat soaks and a pad change and brake bleeding are part of the pit stop routine.

These FSBC knocked caliper temps down 150 to 200 degrees and are well worth their small price. They eliminated a pad change when runnning Hawk Blues during a subsequent Cal Club enduro. As I posted before, some cars benefit a lot from these simple things, other don't.