As reported in previous issues, Corvette returned to the track in the prototype ranks earlier this year. The move was made possible when Grand-Am introduced its GEN3 rules, which effectively opened the sanctioning body's flagship Daytona Prototype (DP) category to cars wearing factory-inspired bodywork. The idea behind the rule change was to improve the visual appeal of the much-maligned DPs, while also enticing more manufacturers to enter the series with theoretically "production based" vehicles.
With the new rules package, design allowances were crafted in an effort to entice car companies that wanted to go prototype racing at the highest level without breaking their corporate piggy banks. The Corvette DP is General Motors' interpretation of these new guidelines. Although designed, developed, and built by Pratt & Miller Engineering, the new body has had to fulfill multiple duties by fitting over existing Riley, Dallara, and Coyote chassis. Teams that signed on to run the Corvette DP body also committed to using a purpose-built, 305ci LS engine rated at approximately 500 horses.
For the Corvette DP teams, this transition meant a steeper learning curve, since they had to adapt to these new engine-and- chassis combinations. As an example, in 2011, Joao Barbosa, the driver of the No. 9 Action Express Corvette DP, was behind the wheel of a Porsche-powered Riley. This year he has a Chevy-powered Coyote chassis.
"The Corvette DP is very different," says Barbosa. "I was very surprised when I tried the car for the first time. The engine works really well. It's very driveable. Corvette has done great aero work, and the car feels great. We've been really fast, quite faster than last year. Even in these early stages of the development of the Corvette, we have a lot to learn, yet the car has been very competitive."
While the Corvette teams have praised their ability to be competitive from the beginning, the other DP entrants have not been as satisfied with the restrictions placed on their cars. Specifically, they have claimed to be at the limits of their aero capabilities. Pratt & Miller engineers fully expected Grand-Am to address this issue at some point, by granting performance concessions to the other entries. The move came after the Detroit round, when race officials signed off on a revised dive plane for the Riley cars.
On the powertrain side, Earnhardt- Childress Racing and GM Powertrain have worked together to develop the Corvette DP's purpose-built LS engine. Using a single supplier has allowed teams to contain costs, while also theoretically leveling the playing field among them. The engine package has proven to be quite robust and competitive, with only two attributable failures to date. While Grand-Am holds a tight grip on the performance parameters in order to balance the competition, the output of the Corvette DP engine is not expected to suffer any drastic reductions.
Beyond the track, GM has scored a hit with the Corvette fans who bring their cars to these events. Taking a page out of the American Le Mans Series playbook and its Corvette Corral, Grand-Am is now hosting a similar function at each event. This has given the hard-core Corvette race fan added incentive to visit both of the competing series.
With the four Corvette DP teams at full speed, and six of the 13 races for 2012 in the books, it's time to pull out the report card and see how the cars have stacked up against the competition.
Expectations were high for the new cars at the Roar Before the Rolex 24. Overall, they performed well with minimal issues. At the end of the three-day test, the Corvette DPs filled the first five positions. However, the top 10 DPs were covered by just three-quarters of a second. This set the stage for the race.
Those high expectations carried over to the Rolex 24. At the end of qualifying, the Starworks Motorsport GEN3 Ford-powered Riley had managed to capture the pole; however, four of the five Corvette DPs entered were in the top seven. After the first hour of competition, the Gainsco Corvette DP was at the head of the pack. The SunTrust Corvette DP, on the other hand, had experienced a catastrophic engine failure and was finished. As the race progressed, a series of accidents, mechanical issues, and poor pit stops wiped out any realistic chance of an overall win by a Corvette DP. The Rolex 24 is always challenging and filled with surprises. True to form, in the end, the Ford-powered Rileys had captured the top three spots. Daytona served as a learning experience for all the Corvette teams.
The second stop on the 13-race schedule took place at Barber Motorsports Park. Lady luck was on the side of the Bowtie brigade at the Birmingham, Alabama, track: The No. 90 Spirit of Daytona car captured the pole and overall win, a first for a Corvette DP.
Homestead-Miami Speedway was the stage for Round Three. Torrential rain wiped out any chance of a qualifying session, so the starting positions were determined by the points standings. The No. 8 Starworks Riley Ford started on pole, but the SunTrust Corvette DP captured its first win of the season in a race that was cut short by 52 minutes due to the weather.
Round Four took place at New Jersey Motorsports Park. The SunTrust team backed up its win at Homestead with a pole and an overall win in the Garden State. This was perhaps the strongest showing to that point for a Corvette DP, with the team leading 91 of the event's 117 laps.
The next stop was in Detroit, at Belle Isle. While severe weather was a factor, a few sunny breaks allowed teams to lay down some dry-weather laps for qualifying. In the shadows of GM's Global Headquarters, the Corvette DPs earned the first four spots on the grid. At the drop of the checkered flag, the Action Express Vettes were stacked one and two, with the win going to the No. 9 car.
Heading toward the midway point in the season, the Mid-Ohio Sports Car Course hosted Round Six. Building on the momentum of the previous events, the Corvette DPs captured the top five positions in qualifying. In the end, the No. 90 Spirit of Daytona car took top honors to give the team its second win of the season.
Excepting the poor showing at Daytona, the Corvette DP package has proved to be a winner, at least in the sprint races. However, championships aren't won solely with outright race victories. Grand-Am breaks down the DP championship into four distinct categories: driver, team, engine, and chassis. For GM, the goal is to get the engine title. After the Mid-Ohio event, Chevrolet had 201 points in that category, while Ford had 177, and BMW 173. These numbers are quite good in terms of the engine championship, but they don't translate well to the other categories.
In the team standings, Chip Ganassi Racing, with its BMW-powered Riley, was at the top of the list with 170 points, followed by the Starworks Motorsport Ford-powered Riley with 168. Tied for Second with Starworks was Action Express Racing, also with 168 points, followed by the Spirit of Daytona with 167, and SunTrust with 156. Only three points separated the top four teams.
The driver's championship was also led by both Chip Ganassi Racing squads with 170 points, followed by the Starworks Motorsport entries at 168 points each. The No. 5 Action Express squad came in at 168 points as well. In the chassis class, Riley Technologies had 190 points, while Coyote scored 189, and Dallara 163. Overall, the points in every class were extremely close and indicative of the competitive nature of the on-track action. It also showed that consistency, and finishing a race, sometimes pay off more than the occasional race win.
The second half of the season should be interesting. While Corvette DPs at times constitute more than half of the prototype field, there are no guarantees with regard to the final results. If additional adjustments need to be made in the second half of the season, Grand-Am officials will take a page from the NASCAR, ALMS, and FIA handbooks, and tweak until they feel the field is level. If the momentum continues, Chevrolet is poised to win the engine title, while the other championship categories may come down to the last race.