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A Radical Repeats at a Foggy Thunderhill Enduro

Car number 48 on track at Thunderhill Enduro 2021

The 25 Hours of Thunderhill resumed on the first weekend in December after skipping the 2020 edition. The Team One Motorsports 2 Radical won overall in a race truncated by fog. Drivers Jeff Shafer, Anthony Bullock, Josh Sarchet and Jordan Missig outdueled another prototype in a close race until the final hour. The win is the first overall Thunderhill victory for the team and the second in succession for a Radical SR3.

Course for Thunderhill Enduro 2021

Memories of a very wet and chilly 2019 race were still vivid for many in the paddock and they came prepared for anything and everything. Teams constructed pit areas with walls and heaters. Crews came with layers of clothing. Cars were prepared with lessons learned after rain-induced issues.

Cars in fog during Thunderhill Enduro 2021

Mother Nature had other ideas. While she brought sunny blue skies and reasonably warm weather (at least warm for early December in Northern California), she spun the Thunderhill weather roulette wheel and landed on fog.

Helmets on hood of race car during Thunderhill Enduro 2021

Track full of cars during Thunderhill Enduro 2021

Ominous Omens At the Start of Thunderhill Enduro 2021

A pair of spins at the outset should have been a sign of drama to come. The pole-sitting #64 Team Crowdstrike/Mosaic Motorsports Duqueine LMP3 prototype spun on the warm-up lap. It gave up its starting position, moving to the rear of the field and giving up the pole to the #10 TVI Racing Radical.

After the green flag waved above the field of 36 split, the white TVI Racing Radical had its own spin at the exit of the first turn on its own fluid and miraculously wasn’t collected by the full field charging just behind.

Car spinning out on track during Thunderhill Enduro 2021

Mazda getting tire changed by pit crew during Thunderhill Enduro 2021

Two cars on road in evening during Thunderhill Enduro 2021

Seeing the Light at Thunderhill Enduro 2021

The field battled through the afternoon and into dusk, sunset and the darkness. A December race date means a sunset before 5pm, so darkness comes early and the sun waits for over 14 hours to return.

With so much running at night and very little auxiliary lighting around most of the track, crews equip the cars with a wide variety of lighting apparatuses. In addition, colored lighting strips or other identifiers are mandatory for crews to pick out their cars.

Two cars on road at Thunderhill Enduro 2021

Mazda with added lighting on side for visibility at Thunderhill Enduro 2021

The Weather Has Other Plans for Thunderhill Enduro

After the field battled for six hours and darkness fell, thick and heavy fog descended quickly on the track at 6pm. In a matter of minutes, corner stations disappeared and those on pit lane strained to see vague beams of headlights in the mist.

Even Rudolph the Red-nosed Reindeer could not have charted a course through the soup. Cars stopped on the front straight and were tucked under covers for the night with no work permitted.

Headlights of race cars cutting through thick fog at Thunderhill Enduro 2021

The fog receded sufficiently to enable a 5am restart. Crews and drivers, grateful for a few hours of unexpected sleep, welcomed sunshine that pushed through the fog. Anyone staying more than a few miles away from the track was amazed that Mother Nature had lifted the heavy fog that continued to shroud surrounding areas.

The 25 Hours of Thunderhill became the 17 hours of Thunderhill. Race rulebook section 7.11 explicitly allows officials to extend the scheduled end time for up to three hours if the race is interrupted by fog.

The unique provision covers no other weather conditions—just fog. While the 2021 race was interrupted for eleven hours, section 7.11 was invoked and the race finished at 3pm instead of noon.

Two cars nearly neck and neck during Thunderhill Enduro 2021

Thunderhill Enduro 2021 Gets Back Underway

The car count was lower than recent years, which lightened on-track traffic density. While there were speed differentials across the wide range of prototypes, Mazda Miatas, BMW 3 series, Honda Civics, and others in the field, contact was rare. Teams tracked their competition closely, but all knew they were racing themselves and the clock first.

Team Honda gathered for photo at Thunderhill Enduro 2021

Team Honda Research West is a regular 25 Hours of Thunderhill attendee. The effort of 40 Honda employees brought a pair of brand-new white and red 2022 Honda Civic Si entries.

The new Si has been eagerly awaited by Honda enthusiasts, and Honda used Thunderhill as a public Research and Development test many times in the past.

Honda Civic Si at Thunderhill Enduro 2021

The race cars had a shakedown at Thunderhill in October but otherwise had never competed. Fortunately, Team Honda had road-worthy Si in the paddock as well. The blue Si came an engine donor when the #22 race car required a transplant (yes, engine changes are permitted by Thunderhill racing rules).

The #23 had its own challenges, leaving a trail of smoke in its wake and not seeing the checkered flag. While the outing was not likely what Team Honda had in mind, the strong culture of Honda employees that crave the test of motorsports is still worthy of recognition.

Crowdstrike/Mosaic motorsports team working on Duqueine LMP3 prototype for Thunderhill Enduro 2021

The Crowdstrike/Mosaic Motorsports team knew they had a weapon with their Duqueine LMP3 prototype, an experienced and talented crew, and a lot of preparation. They also knew their car had a history of axle reliability issues and prepared for failures.

Sure enough, two axle failures ultimately cost them the victory—the last coming while leading with an hour to go. While a fix only took twenty minutes, the margin at the checkered flag was 6 laps—about a 10 minute gap.

Car with raised doors on track at Thunderhill Enduro 2021

Civic Type R on track at Thunderhill Enduro 2021

A pair of Civic Type R entries brought a lot of attention. Spoon Sports, a well-known Honda aftermarket tuning shop and motorsports outfit, won their class with a blue and yellow Type R. They took the win with a 12 lap gap over the DIG Motorsports Ford Mustang.

Funduro Racing car on track at Thunderhill Enduro 2021

The glorious oddball award for the race has to go to the class-winning Funduro Racing entry. The tube-frame roadster body with a four-cylinder VW engine looks like an outlaw Porsche 356 or VW Beetle.

With lap times just above the 2 minute mark, the roadster was competitive but—more importantly—reliable. It outlasted others, including a Civic Type R that suffered a broken engine mount which caused an oil line failure. The Type R crew made repairs and recovered to earn a second place in class.

Front view of Funduro Racing entry on track near man at Thunderhill Enduro 2021

Two cars rounding curve on track at Thunderhill Enduro 2021

Long line of cars on track near end of Thunderhill Enduro 2021

Say Goodbye to Thunderhill Enduro (Until Next Year!)

The 25 Hours of Thunderhill prides itself on running a wide variety of equipment around a great natural terrain road course. Stay tuned to see what comes up when Mother Nature spins the roulette wheel on the first weekend of December 2022.