When the factory-sponsored C5-R Corvette race cars debuted in the '99 Rolex 24 Hours at Daytona, optimism was so thick you could cut it with a knife. But, long before the end of that grueling 24-hour endurance race, any hope for success had long since vanished. Transmission problems, differential failure and, ultimately, an engine failure dashed all hopes of earning a coveted class win.
With hindsight it's easy to identify where, when, and why things went wrong. But at that time the optimism seemed entirely reasonable. After all, in two years of development and testing preceding the Daytona contest, the C5-R racing "mule" proved to be extremely fast. In fact, at certain tracks it exceeded the existing GTS class record during testing, even at Road Atlanta in the rain! "Don't get too excited about that," those in the know told the rest of us. For one thing, a rules revision would allow competitors to use a wider rear tire beginning in 1999, and the existing track records were set by Vipers running on the narrower tires. There was no telling what the Vipers would do on the new tires.
"Also," those in the know again cautioned, "never underestimate what your opponent is really capable of." How right they were! The factory Corvette team eventually worked out their mechanical bugaboos so that by the end of the '99 season the C5-Rs were becoming extremely reliable. But reliable or not, they still couldn't catch up to the ferocious, factory-sponsored Vipers. The Corvettes never seemed too far off the mark, recording a second place finish at Sears Point, a fourth place at Road Atlanta, another second place at Laguna Seca, and a third place at Las Vegas. No matter how hard they tried, though, the Oreca team factory Vipers were one step ahead. Were the Vipers sandbagging, running only hard enough to stay out in front without showing their entire hand? Or were the Corvettes forcing them to go that much faster? Probably a little bit of both.
"The Vipers had no real competition until the Corvettes came along," points out one GM engineer, "so they weren't really trying. We made them try, and that ultimately showed us just how good they were and just how much work we had to do."
The C5-Rs went into the '00 season with a valuable year of actual racing experience under their belt and a couple of major improvements incorporated into the cars. One of the more important of those improvements, a larger engine, actually came on board in October 1999 at the Laguna Seca race.
Chevrolet engineers realized early on that American Le Mans Series rules, intended to level the playing field among cars with different size engines, were skewed in favor of larger displacement engines. Though the Dodge Vipers had to use a smaller intake manifold air restrictor on their 8-liter V-10 engines compared with the restrictors Corvettes used on their 6-liter V-8, the Vipers had a clear power advantage. To overcome this, GM Racing engine point man John Rice and Kevin Pranger, engine development specialist from Katech (the company that actually builds the C5-R's engines), bored and stroked the LS1 to 7-liters. At this displacement the Corvette engines are just about the equal of the Viper's. Besides the larger engine, another important change that helped the Corvette racers in 2000 was what GM calls the second generation C5-R chassis. Though work actually began on the new chassis in 1999, the first one was not ready to race until the Mosport ALMS race in August 2000. The new car won high praise from team drivers Ron Fellows and Andy Pilgrim, who led most of the Mosport race only to fall into second place at the end when the rain soaked tracked dried off and their Goodyear rain tires forced the Corvette to slow down. In a heart-wrenching finish the Corvette crossed the finish line just 0.353 second behind Oreca's class winning Viper.
Like the first generation C5-R, the new chassis is built around production C5 Corvette framerails and suspension cradles that come straight off the Bowling Green assembly line. Unlike the first design, however, the new one utilizes fabricated control arms rather than stock production arms. The custom arms are similar to the stock units except they are 1.5-inches longer, giving the new car a 3-inch wider track. The broadened stance improves handling by decreasing roll and lowering the center of gravity. It also increases the tires' contact area and decreases the loads the tires must sustain, both of which lead to better handling and longer tire life.
A final advantage of the widened track is increased aerodynamic downforce. The widened body, necessitated by the wider track, benefits from a wider splitter and diffuser. The splitter and diffuser are parts of the underside of the body that direct the flow of air between the car and the track surface to increase downforce. In addition to improving the C5-R's handling, the second generation chassis also offers the benefit of reduced weight. The two new race cars tip the scales at about 110-pounds less than the initial pair.
As with engine size, weight is carefully governed by the series rules. Each class has a minimum weight that cars must meet, and formulas that try to even the performance potential of cars that weigh in differently. A smaller engine air restrictor hampers lighter cars while heavier cars benefit from a larger one.
So, why build a lighter car if that will only lead to a smaller restrictor and less engine power, or that will require the addition of weight to meet the minimum number dictated by the rules? The first reason is that all weight is not created equal. By building a car that's too light to begin with, engineers can specify exactly where the required extra weight is to be placed. They actually ballast the cars by adding bars of a heavy metal alloy to very specific areas. By directing where the weight goes they can improve handling by optimizing balance and lowering the center of gravity.
Also, reduced weight, at the cost of some engine power, is desirable at certain tracks but not so at others. For the '99 season, and until the Mosport race this last August, the team could not take advantage of this because they could not get the first generation C5-Rs below 1,200 kg. In contrast, the new chassis can be pared down to the next weight break, 1,150 kg. On tight tracks like Laguna Seca and Mosport, which place a premium on handling over raw power, the C5-Rs will turn better lap times at 1,150 kg, even with less power. At high-speed tracks like Daytona and Road Atlanta, the higher weight (and reduced handling and braking performance) are more than made up for by the increased engine power. Besides with the wider, lighter chassis and improved power, thanks to the 7-liter LS1, the Corvette team gained ground in another area this past season.
At the level where the Corvettes and Vipers are competing, every race, including the 10-, 12-, and 24-hour endurance contests, is an all out sprint to the checkered flag. With that kind of intensity, even the smallest problem, mistake, or simple bad luck can separate the winner from the losers. And with that kind of intensity the skill and dedication of the crew can make all the difference in the world. Like an engine as it gets broken in or racing slicks as they get warmed up, the crew became more disciplined, more unified, and better in every measurement as they got more experience.
The many technical improvements to the C5-Rs and the improved performance of the team came together on Labor Day weekend at the Texas Motor Speedway. Ron Fellows, Andy Pilgrim and the crew overcame incredible heat to record a decisive win over the factory Vipers. "The win in Texas was important," said team manager Gary Pratt, "not only because it was our first victory but also because of the venue. Texas was a new addition to the series and it's a brand new speedway so everyone went there with a clean sheet of paper. We've shown that on a level playing field, where the Viper's years of experience and data don't mean as much, we can win with a comfortable margin."
Four weeks after the Texas race, Team Corvette demonstrated that their stunning victory in Texas was not a fluke. Two C5-Rs and three factory-backed Vipers traded the GTS class lead many times during the grueling 1,000-mile/10-hour endurance race, but when the checkered flag waved, a Corvette roared across the finish line first.
In testimony to just how competitive the GTS class is, the Vipers rebounded to victories in final two races of the '00 season. At Laguna Seca, one of the Corvettes lost precious time in the pits after being rear-ended by a Viper on the second lap, while the other C5-R fought handling irregularities and poor traction the whole race. In the final North American race of the season, at Las Vegas Motor Speedway, the No. 3 (Ron Fellows and Andy Pilgrim) car was put out of the race by a tremendous right-rear tire explosion at the end of the front straight. The other car had handling problems and finished a disappointing third, lapped by both surviving factory Vipers.
Though they did not finish the '00 season on the high note they wanted, everyone on the Corvette team is understandably proud of their successes. The consecutive GTS class wins in Texas and Atlanta demonstrated to Dodge and the world what the team had known since their outing at the '00 Rolex 24 Hours at Daytona in February. The C5-R emerged from its initial year of competition drastically improved and poised for success. It wasn't a question of "if," but rather it was simply a matter of "when?"
Going into the '01 season, the future for Corvette racing looks bright indeed. The C5-Rs will compete in all of the North American ALMS races as well as the 24 Hours at Daytona and the 24 Hours of Le Mans. Though the factory Vipers will not contest the entire series as they have in the past, they will likely show up for the major endurance contests. A small army of factory-supported, privateer Vipers, as well as the usual contingent of GTS Porsches, promises to keep the competition keen.
And there is a new kid on the block, the very controversial Saleen S7, out of the shops of well-known Mustang "tuner" Steve Saleen. Designed and actually built by British race car specialist Ray Mallock, the Saleen S7's mid-engine design and carbon fiber/aluminum honeycomb-stiffened tube frame make it look more like a prototype than a GTS class racer. The American Le Mans Series' decision to classify the Saleen as a GTS competitor is highly controversial since GTS racers are supposed to be modified production cars and the Saleen is, at the moment a one-off, purpose built racer. In theory at least the Saleen S7 holds the potential to thoroughly dominate the GTS class but it remains to be seen whether the Saleen team can capitalize on their opportunity.
Considering the always threatening Vipers, ever fast and reliable Porsches, and potentially dominant Saleens, the Corvette team's quest for a series championship in 2001 promises to be a fierce battle. It also promises to provide racing excitement, the likes of which have not been seen in decades, so stay tuned!