I've boiled brake fluid before. Could feel it gurgling in the caliper. There's a DOT 5.1 fluid that is the same formula as DOT 3 and 4, not silicone, but has the same higher boiling points as DOT 5. We didn't have ducts at that time, but with them, the car is much better. I'd go for cooling ducts to fix your problem. DOT 5.1 is just a band-aid. The Hawk blue worked great for us, but lasted 28 hours, so we had to swap them out for parts store crap, and there was no comparison. I'm wondering how one is supposed to bed the pads in at the track, though, when the race is going on.