From the early days of the marque when mechanical fuel injection and disc brakes were novelties to the advanced carbon fiber construction and sophisticated CFD aerodynamics of the 21st century, Corvette has long been a leader in developing and refining new technology. That process is continuing in 2008 as Chevrolet's factory road racing team develops new components and materials for its transition to E85 ethanol racing fuel.
"We're willing to take on the challenge," said Corvette Racing program manager Doug Fehan. "We know this is the future of racing. Someone has to be the first, and when you're the first, you're inevitably going to encounter new challenges."
Corvette Racing first track-tested the renewable alternative fuel in late February. A post-test inspection revealed that the initial formulation of the E85R fuel specified by IMSA, the ALMS sanctioning body, was adversely affecting the adhesive used to construct the race cars' twin fuel cells. Consequently the team will compete in the season-opening Mobil 1 Twelve Hours of Sebring with the E10 ethanol/gasoline blend that was used in 2007 while new fuel cell adhesives and assembly techniques are developed.
"The performance of E85 ethanol racing fuel was firmly established in our initial track test," said Fehan. "Now the team is working with the fuel cell manufacturers, IMSA, and our technical partners at the Ethanol Promotion and Information Council to develop an advanced ethanol fuel cell. As a manufacturer team, safety is paramount at Corvette Racing, and we will always err on the side of caution. Just as every new component in a production GM vehicle must be exhaustively tested, every new part that goes into the Corvette C6.R race cars must be tested and validated. It wasn't feasible to do this in the weeks since the program was announced, but I am confident that we will resolve the situation in a short period of time.
"Corvette Racing has long been considered a leader in safety," Fehan noted. "We introduced HANS devices before they were required, the right-side driver safety net, energy-absorbing side impact boxes, long-reach fuel and vent nozzles, and other safety innovations. Along with Corvette's leadership in safety technology, we also want to be a leader in alternative fuel technology. We're totally convinced that racing is eventually going green. Somebody has got to be first, and we're willing to do that, just as we have on other issues.
"The challenge we now face is to develop a fuel cell that can handle ethanol/gasoline blends with absolute safety," Fehan reported. "The fuel cells that are currently available are certified for either gasoline or alcohol-type fuels such as ethanol and methanol, but not gasoline/alcohol blends. Working alongside our technical partners, we're going to dedicate the resources and do the research to solve this."
The fuel cell bladders used in the Corvette C6.R race cars are constructed from numerous pieces that are bonded together to create a complex assembly of baffles, reservoirs, and mounts for high-pressure electric fuel pumps. Based on the dual-tank design of the production Corvette, the C6.R race car's two fuel cells are mounted alongside the driveshaft tunnel behind the driver's compartment and joined by a connecting tube.
"The second challenge is that the FIA (Federation Internationale de l'Automobile, racing's international sanctioning body) mandates that no car can carry more than 110 liters of fuel," Fehan explained. "So until all entries are using the same fuel, the series has to create an energy balance between cars that are running E85 ethanol, E10 ethanol, and diesel. It's not reasonable for one car to carry 70 liters of fuel and another to carry 110 liters because that would create significant differences in performance, handling, braking, and refueling times. The goal is to create close competition for the fans, and that requires careful balancing of the performance characteristics of the various fuels and vehicles. There are a number of ancillary issues that have yet to be resolved since this program was announced."
Corvette Racing will make its season debut in the opening round of the 12-race ALMS series, the 56th Mobil 1 Twelve Hours of Sebring, on Saturday, March 15, 2008. The race will start at 10 a.m. ET and will be broadcast live by SPEED, which will begin its coverage at 9:30 a.m.