[Tom Goldman]

I use Wilwood Super 570 fluid in my SG car stopping at nearly 170 and all the S/SS cars I work on .
Its boiling point of 570 degrees is the highest of any DOT 3-4 type fluid.
This means it can absorb more moisture from the atmosphere as all glycol based fluids do without boiling at low temperatures.
Silicone DOT 5 fluids are not hygroscopic ,so they do not absorb the moisture that enters the system ,meaning that the water absorbed will stay separated, and boil at 212 degrees, causing a softer pedal.
Dot 5 should never be used for racing.
One thing that most Drag racers do not do regularly is flush out and change the brake fluid.
When you see cloudiness or dark discoloration of the fluid, thats a warning sign of contamination and overheating . ....This is what leads to most brake master cylinder and caliper failures . the seals themselves dont actually fail , its the corrosion of the bores caused by the contaminants in the fluid.
The fluid should ALWAYS be clean and clear as it came from the container. ....You can get a battery operated test pen for about $25 ,quick easy way to check the fluid condition.
I service some amateur road race Corvettes . ...The sanctioning body REQUIRES the brake fluid be changed before each event and certified ,along with other components by a certified inspector.