Powered by cellulosic E85R ethanol racing fuel made primarily from wood waste and armed with a variety of energy-saving technologies, Corvette Racing is aiming for an overall victory in the inaugural American Le Mans Series Green Challenge. This race-within-a-race will be contested on October 4 in conjunction with the 1,000-mile/10-hour Petit Le Mans at Road Atlanta, the 10th round of the 11-race series.

Under criteria developed by the U.S. Department of Energy, the U.S. Environmental Protection Agency and SAE International, the Green Challenge will determine the winning entries in the GT and Prototype classes based on performance, fuel efficiency and environmental impact. Each car will be ranked according to the amount of energy used, the greenhouse gases emitted, and the amount of petroleum displaced – while racing flat-out for a class title in the crown jewel of the ALMS.

"The Green Challenge adds an entirely new dimension to racing," said Doug Fehan, Corvette Racing program manager. "It's not simply a race to the checkered flag – the Green Challenge takes science, technology and engineering to an entirely new level in motorsports.

"The determining factors in the Green Challenge include weight, fuel consumption, the speed of the vehicle, distance traveled, emissions from the exhaust pipe, and the environmental footprint of the fuel that's used," Fehan said. "It is a huge, huge challenge, and one that we've embraced because it sends the right message – and because it's the right thing to do. Corvette Racing's commitment to green racing reflects the position of General Motors in finding new ways to power vehicles that are exciting for our customers."

While Green Challenge winners will be named in both the GT and Prototype classes, Corvette Racing is aiming for the best overall score in the competition.

"With vehicles that span the spectrum from exotic prototypes to production-based cars and fuels that range from cellulosic E10 and E85 ethanol to clean diesel and hybrids, the Green Challenge is a true benchmark for race teams to compare their engineering capabilities," said Steve Wesoloski, GM Racing Road Racing Group manager.

"How does our GM small-block V-8 running on E85R ethanol stack up against Audi's TDI diesel in efficiency and environmental impact? We've taken the approach that cellulosic ethanol is an important step toward a greener future, not only in racing but in GM's gas-friendly to gas-free vehicles on the highway. The Green Challenge will give every team an unprecedented opportunity to gauge its technology against world-class competition."

One of the key elements in Corvette Racing's strategy to win the first Green Challenge title is cellulosic E85R ethanol racing fuel. This second-generation ethanol fuel has powered the twin Compuware Corvette C6.R race cars in every round of the ALMS since April. The cellulosic ethanol is made from waste wood collected in the Black Hills National Forest as part of a wildfire prevention program.

Undergrowth, dead trees, branches and bark that would otherwise be burned are converted to cellulosic ethanol at a pilot plant in Wyoming. This conversion process also produces lignin (the remaining wood fibers less their sugar) that is used to power the plant and to supply electricity to the power grid. Co-products of the ethanol conversion are used in composite woods, paints, cosmetics, livestock bedding, and livestock feed supplements.

"In terms of the Corvettes' LS7.R racing engines, the transition from the E10 that was used last season to the E85R that we are using this year was seamless," said Roger Allen, program manager for the Corvette C6.R. "We focused on making the engines as efficient as possible by recalibrating the ignition timing and the air-fuel ratio for E85R, and optimizing fuel cut-off under deceleration to reduce consumption."

Corvette Racing engineers have analyzed every aspect of the race cars to gain a competitive advantage on the race track. These enhancements will also play a critical role in the Green Challenge competition.

"Reducing losses caused by friction, aerodynamic drag, and rolling resistance improves overall efficiency," explained Wesoloski. "By minimizing these losses, more of the fuel's energy can be used to propel the race car.

"For example, Corvette Racing has worked with Mobil 1 to develop lubricants that reduce friction throughout the drivetrain – not just in the engine, but in the gearbox as well," he said. "We've changed from conventional steel wheel bearings to low-friction ceramic bearings – now when the car is on jackstands, you can turn the front wheels as easily as spinning a bicycle tire.

The aerodynamic refinements that have been developed to increase top speed also reduce drag and the power that's required to push the car through the air. Michelin has an ongoing program to reduce the tires' rolling resistance while improving forward and lateral grip. Just as in a production vehicle, a number of small gains in a race car can add up to produce a significant improvement in overall efficiency."

On the highway and on the race track, the driver's right foot has an impact on fuel mileage. While winning the Green Challenge tops Corvette Racing's to-do list at Road Atlanta, Petit Le Mans is ultimately a race, not an economy run. The battle for the GT1 drivers championship is still being waged, with Johnny O'Connell and Jan Magnussen holding a 23-point lead over Oliver Gavin and Olivier Beretta with 55 points available in the final two races.

"One of the lessons we've learned in racing at Le Mans is that the drivers play a crucial role in fuel efficiency," Wesoloski said. "A driver can make a difference by how smoothly he makes the transition from braking to full-throttle acceleration on corner exit.

Allowing the car to roll freely going into a corner before applying the brakes burns less fuel. With the telemetry and data acquisition that we have in GT1, our engineers can monitor fuel use throughout a stint, and the drivers can adjust their style to stretch the fuel load between pit stops."

From the Fans: Corvette Racing program manager Doug Fehan is one of five finalists for the ALMS From the Fans award. The award, which is determined by online voting through Sunday, October 5, will be presented at the season-ending banquet in Monterey, Calif. Other finalists are Acura, Duncan Dayton, Paul Drayson, and Robertson Racing.

Friends of Corvette Racing can support Fehan's run for his second From the Fans award by voting at http://americanlemans.com/poll/poll.aspx 

Voting is also open through October 5 for the Most Popular Driver award, won by Corvette Racing's Ron Fellows for the last four consecutive years: http://www.americanlemans.com/Poll/MostPopularDriver.aspx  

O'Connell Charity Auction: Corvette Racing driver Johnny O'Connell will host his annual charity auction at 6:15 p.m. on Friday, October 3, at Road Atlanta's infield winner’s circle. O'Connell organized the auction in 2001 in memory of his father to raise money for the Alzheimer’s Association and The Guest House, a senior citizen day care center in Gainesville, Ga.

Drivers, teams, and manufacturers have donated memorabilia and merchandise, and O'Connell will play the role of auctioneer. The event has raised more than $200,000 for charity to date.

Mad Max's Birthday: Max Papis returns to Corvette Racing as the third driver of the No. 4 Compuware Corvette C6.R at Petit Le Mans. The popular Italian will celebrate his 39th birthday on Friday, October 3, on the eve of the endurance race.

Corvette Racing’s next event is Petit Le Mans, the 10th round of the 2008 American Le Mans Series, at Road Atlanta in Braselton, Ga. The 1,000-mile/10-hour race is scheduled to start at 11:15 a.m. EDT on Saturday, October 4. SPEED will televise the race live starting at 11 a.m. EDT. 

- Rick Voegelin - also photo