The best highest performance racing brake fluid on the market today is CMS Performance RF1 with a dry boiling point of 622ºF!
Competition Motorsport CMS Performance RF1 DOT4 Racing Brake Fluid (500 ml) from $24.95
CMS Performance RF1 DOT4 622oF Racing Brake Fluid Buy in bulk and save. Get six bottles and save 15%, or a case of 12 and save a whopping 25%! The Highest Dry Boiling Point Racing Brake Fluid You Can Buy CMS Performance RF1 fully synthetic Racing Brake Fluid is formulated to provide the highest performance under racing and track-day conditions, where braking systems operate at very high sustained temperatures. RF1 exceeds all DOT 3 & 4 requirements and is compatible with all DOT 3, 4, and 5.1 fluids. (Not compatible with DOT5 or mineral-based brake fluids.) There is perhaps no single safety system more important in racing than brakes. And no part of that system is more critical than brake fluid. At Competition Motorsport, we got tired of (and a little nervous) using "racing" brake fluid on the track that didn't live up to its claimed performance. So we did something about it. Manufactured in partnership with Orthene Chemicals, a British brake fluid supplier to professional race teams in Formula 1, WEC, and many other pro series, CMS Performance RF1 Racing Brake Fluid is formulated to maintain consistent viscosity, lubricity, and compressibility at extreme temperatures and line pressures found in racing, track days, and spirited driving. Bottom line: you can spend more money, but you can't buy higher-performing racing brake fluid! CMS Performance RF1 Racing Brake Fluid Specifications: Typical dry boiling point: 622° F (328° C) Typical wet boiling point: 399° F (204° C) Exceeds DOT3 & DOT4 standards Individual 500 ml (16.7 oz.) bottles Click Here For The RF1 Product MSDS Sheet A Note About Brake Fluid Boiling Points DOT 4 brake fluid like RF1 is hygroscopic, meaning it attracts water over time sitting in your brake lines and reservoir. At high brake temperatures, this water can boil in your car's brake lines, causing the fluid in the lines to become compressible. That's what you feel when you experience brake fade. This is why the "wet" (aged fluid) boiling point of any brake fluid is substantially lower than the "dry" (brand new fluid) boiling point. Since time is the enemy of brake fluid performance, the best practice is to replace your racing brake fluid before each track event/weekend. At a minimum, flush it with new fluid at least every three months if you're consistently racing and/or driving at track days. A couple bottles of fluid will flush most sports cars or race cars. It ends up being pretty cheap insurance against learning about brake fade the hard way.
Castrol React SRF Synthetic Racing Brake Fluid
Castrol Castrol React SRF Synthetic Racing Brake Fluid $74.95
Castrol React SRF Racing Brake Fluid Castrol React SRF Racing Brake Fluid is an ultra-high performance brake fluid popular with many of the highest performing auto racing teams around the world.  The key to Castrol SRF brake fluid's superior performance is its silicon-ester technology.  Not only is it less hygroscopic (i.e., it absorbs less water) than typical glycol-based brake fluids, Castrol SRF also reacts chemically with any absorbed water to further reduce its adverse effects on high-temperature braking performance. The result is an almost unheard of 518° F (270° C) wet boiling point -- more than 100° F higher than most other racing brake fluids! Exceeds SAE 1703, ISO 4925, JIS K2233, FMVSS No. 116 DOT3 and DOT 4 specifications. Note: Castrol SRF is not a silicone-based brake fluid (e.g., DOT 5) and is compatible with most factory brake systems and fluids.  Always follow vehicle manufacturer's recommendations when adding brake fluid. TYPICAL PROPERTIES: Dry Boiling Point: 590°F (310°C) Wet Boiling Point: 518°F (270°C) Superior anti-vapor lock properties One-liter (1000ml) bottle
Motul RBF 600 Racing Brake Fluid (500 ml)
Motul Motul RBF 600 Racing Brake Fluid (500 ml) $19.95
Motul RBF 600 Racing Brake Fluid Motul RBF 600 is a 100% synthetic fluid for hydraulic-actuated brake and clutch systems. Specifically designed to resist the high temperatures of actuated (steel or carbon) racing brakes and clutch systems.Motul RBF 600 far exceeds the standards of DOT 3 and DOT 4.The RBF 600 container is filled with Nitrogen to increase shelf life and eliminate contamination while factory sealed.Extremely high dry- and wet-boiling points help prevent vapor lock and brake fade during hard use.EXTREME THERMAL RESISTANCE AND STABILITY: The elevated dry boiling point of RBF 600 (312°c / 593°F) enables effective braking even under the extreme conditions of competition.VERY EFFICIENT WHEN RAINY: The very high wet boiling point (216°c / 420°F), is superior to conventional brake fluids provides a particularly efficient braking system in rain and put back the apparition of vapor lock. Do not mix DOT 4 brake fluid with silicone (DOT 5 silicone base) or mineral-based fluids (LHM).
Motul RBF 660 Racing Brake Fluid (500 ml)
Motul Motul RBF 660 Racing Brake Fluid (500 ml) $31.12
Motul RBF 660 Racing Brake Fluid Motul RBF 660 Brake Fluid is 100% synthetic racing  brake fluid (DOT 4) for use in extreme temperature & racing applications. It is suitable for all types of hydraulic brake and clutch actuators requiring non-silicone synthetic fluid. Widely exceeds the DOT 3, DOT4 and DOT 5.1 standards (except for DOT 5.1 viscosity at - 40°C). EXTREME THERMAL RESISTANCE AND STABILITY Very high dry boiling point (325°C / 617°F), superior to conventional DOT 5.1 non silicone base, DOT 5 silicone base fluids, and DOT4. Motul RBF 660 enables effective braking even under extreme conditions. EFFICIENT WHEN RAINY High wet boiling point (204°C / 400°F) far exceeds the requirements of DOT 3, 4, and 5.1, enabling brake efficiency while rainy. Reduces the risk of “vapor lock”. Amber in color. Do not mix DOT 4 brake fluid with silicone (DOT 5 silicone base) or mineral base fluids (LHM).