There’s nothing in racing that puts as much strain to both man and machine quite like an endurance event. For 25 hours, both are pushed to the very edge of their capabilities, with the winners being those who not only survived this gauntlet, but those who truly thrived. Every year in December, aspiring teams make the pilgrimage to Thunderhill Raceway Park in Willows, California, located just north of San Francisco, for the 25 Hours of Thunderhill sanctioned by the National Auto Sport Association (NASA).


For 2015, we partnered up with Bullet Performance again following their successful E1 class championship win with us at Thunderhill in 2014. This time, Bullet Performance brought out an E46 featuring our Triton TS240X front calipers paired to a 330mm 2-piece free floating rotor. This combination was developed in close partnership with Bullet Performance to ensure maximum performance, particularly in an endurance race scenario. Compared to the OE kit, our also kit shaves over 20lbs from the front axle, allowing for more nimble and responsive handling.


Our goal during this event was to gather as much data as possible pertaining to the temperature and wear patterns of our brake system. We started o by taking measurements of the rotors and pads prior to start of the race, then comparing how much they’ve worn by the end of the race. Track and component temperatures were also logged through the use of an infrared thermometer. We will use these readings to associate the time under heat in addition to pad wear, which could then be compared to dynamometer data to create a model that can predict the wear life of the kits. This data will then be used to provide our teams and customers with an estimated service interval and add to our ever-growing pad compounds available with our kits. At the end, our kit performed to our expectations, unfortunately, the cool and rainy conditions of the track prevented us from being able to push the car further. Feedback from our drivers were overwhelmingly positive, all of whom noted that the pedal feel and dynamic control were impeccable. Despite the suboptimal race conditions, we found that wear was consistent and comparable to what was expected from the OEM kit. We were also able to confirm through our data,that our brake system ran 18% cooler compared to the OEM brake system under the same exact conditions.


Our dedication to improving our products means that every piece of race-condition data is implemented to improve our products for the next time that car hits the track. Through this process, we work towards more podium finishes and ensure that Sparta Evolution kits are one of the most competitive options in the market.
A BIG thanks is in order to team at Bullet Performance for their amazing effort at Thunderhill!