Acura TL 25 Hours of Thunderhill (2004) : A nearly stock Acura TL built and driven by engineers from Honda R&D Americas accomplished the seemingly impossible by winning its class and finishing third overall at the “25Hours of Thunderhill” race at Thunderhill Park Raceway in Willows, California.

Team Honda Research, composed of members of the unit that designed the TL, completed 650 laps to finish 49 laps ahead of the second place car in its class. The team was made up of four drivers, an 8-person pit crew team and other R&D associates who were instrumental in preparing the car to National Auto Sport Association (NASA) Honda Challenge Rules.

The 25 Hours of Thunderhill, which ran from 11 a.m. Dec. 4 to noon on Dec. 5 is the self-billed “king of
enduros” and “most severe endurance race on the planet.” This year’s event featured 59 race teams with the overall winner, a Porsche 911 RSR fielded by Team Crazy Redhead Racing, completing 681 laps on the 3.02-mile course.

The engineers decided to build and field a TL racecar after several attended last year’s Thunderhill race.

We wanted to take what we think is the best-in-class sedan, which happens to be front wheel drive, and put it up against our rear-wheel-drive competitors under the most grueling race conditions available,” said team member Jeremy Lucas.

Lucas and Brian Shanfeld assumed the roles of project leaders and submitted a proposal to R&D management. The project was approved, providing
the team with funds for car prep, travel and the event entry fee. Lucas, Shanfeld and their teammates then set out to build, on their own time and within the limits of the budget given them, a race-prepped TL.

The new TL is such a great performer that with just minor modifications to make it race-ready, we thought we’d have a pretty good shot,” explains
team member Chad Gilsinger.

The team had only ninety days to prepare a stock TL to NASA Honda Challenge specifications. While the engine, drivetrain and brake system remained stock, the team augmented the TL’s 3.2 liter V6 with a cold air intake, and a custom exhaust header from Prototype Racing. A large diameter exhaust, a lightweight flywheel and a performance clutch were provided by Comptech USA.
The suspension was modified with custom H&R coil-overs, a Progress adjustable rear sway bar and adjustable SPC camber ball joints and links. Lightweight Enkei racing wheels and Toyo RA-1 race compound tires were used for increased grip. Based on the results of windtunnel testing, an Acura A-SPEC aero kit was applied to lower the coefficient of drag, and a rear wing was added for increased high speed down force. These modifications plus the removal of luxury and convenience features reduced the TL’s weight to 2797 pounds (without driver), a 675 pound reduction from the stock TL.

Team Honda Research entered the TL in the E0 class for production-based racecars. It qualified second in class, and sixth overall to start the race on the outside of the third row. A nighttime skirmish with a curb while avoiding another car at the 10.5 hour mark resulted in a bent right front wheel and a broken upper ball joint. But after 11 minutes in the pits, the TL was back on the track and completed the race with no further incidents.

We take a lot of pride in this result because the TL was completely designed by our team at Honda R&D,” said Shanfeld. “We can’t wait to be back next year.”


For more information:
Mike Spencer (310) 783-3165
Jessica Fini (310) 783-3396