Yost Autosport at the 25 Hours of Thunderhill
by Mike Bonanni
The 25 Hours of Thunderhill; North America’s longest endurance race is no joke. Yost Autosport team principle Jordan Yost has always said “You have to know in January that you’re going to race the 25 Hour in order to have any chance of making it.” The race itself takes place the first week of December every year at Thunderhill Raceway Park in Northern California. Its cold and most years the race is thrown a curve ball by Mother Nature whether it be rain, fog, or both. The range of machinery spans from Spec Miatas and 100 horsepower Honda Fits all the way to factory GT3 spec race cars and top level prototypes providing an incredibly interesting race to not only watch, but be a part of, completely different from any other endurance race out there. Just finishing this race is something almost half of this year’s 65 car field didn’t accomplish.
For Yost Autosport, it was our second consecutive year competing in the 25 Hours of Thunderhill. In 2014 the 25 Hour was the first race for our newly built BMW M3 race car and we are proud to say that in our first time out we finished the race. Now that completing the race was under our belt we came into the 2015 event with the goal of being competitive. The M3 received a complete teardown and rebuild after the 2014 25 Hour. We then proceeded to race it in three other shorter endurance races throughout the year finishing on the podium in two of the three, winning our last event going into the 25 Hour. Confidence was high going back to this race with a much faster car and a lot more working knowledge learned from our first season of endurance racing.
The team arrived Wednesday and spent the entire day setting up our pit area to create a comfortable and functional space for the team to remain comfortable and at the ready for 25 hours straight come race time. Thursday was spent double checking all major components of the car and by Friday it was finally time to hit the track. Practice was being run all day long with qualifying for the race scheduled just after nightfall. The weather was overcast with thick gray low hanging clouds covering the circuit, a contributing factor to our first problem of the weekend; our car was too loud. It may sound silly as race cars are generally very loud but this particular track and event have a maximum sound limit of 95db measured at 50 feet. This is a problem we did not have last year when the weather was much clearer. Overcast weather causes the sound waves to bounce off the low slung clouds and amplify.
The track’s procedure when a car is too loud is to pull them off-track and let them back out after making modifications to quiet the car. We had come prepared with alternate exhaust tips that angle away from the side of the track where the microphone sits, a common fix among racers. This doesn’t actually make the car any quieter it just re-directs the sound but as long as the trackside microphone reads below the maximum limit the track doesn’t care. Unfortunately for us, it wasn’t enough and we were still too loud. We spent the entire day coming in, trying some sort of fix, going back out and failing each time. While a team member drove hours across different towns searching for universal mufflers we could install for an actual fix, our goal at the track was to find any temporary solution that would allow us to run at least a few qualifying laps.