THE SERIOUS BUSINESS OF FUNNY CAR AERODYNAMICS
With the introduction of the Chevrolet Monte Carlo on the high-profile stage of professional Funny Car competition in 2004, GM Racing reaffirmed Chevy’s commitment to excellence in drag racing’s most spectacular nitromethane-burning category. In its first season in quarter-mile competition, Chevy’s Monte Carlo Funny Car captured seven nationalevent victories, advanced to 13 final rounds and DOWNLOAD | X05MO_CH262 earned low qualifying honors six times. In 2005, GM Racing developed a Chevrolet Monte four Monte Carlo drivers finished in the top 10 in Carlo Funny Car that combines the identity the NHRA Funny Car standings: Tommy Johnson Jr., of the production car with the aerodynamic Tony Pedregon, Cruz Pedregon and Del Worsham. characteristics required to create a competitive race car. GM Racing also developed a Monte Carlo body specifically for the Top Alcohol Funny Car class, which Bob Newberry drove to the 2005 TAFC championship. “I’ve had more Top Alcohol Funny Cars than I can count, but the Chevy Monte Carlo is the best I've ever raced,” said Newberry. “The construction of the Monte Carlo Alcohol Funny Car body involved a four-part development team: GM Racing, Roush Industries, S & W and myself. The body had to be approved by NHRA and could not be modified in any way after it came out of the mold. That called for the development of an entirely new race car because there wasn't a current, state-of-the-art Alcohol Funny Car body in competition. Starting with the Monte Carlo that’s used in the nitro-burning Funny Car class, we were able to make some modifications with the approval of the NHRA, and the result was an outstanding Top Alcohol Funny Car body.” A sophisticated street car with race-inspired styling, the Monte Carlo is a classic Chevy nameplate. The strengths of today’s Monte Carlo make it one of America’s best-selling cars in the midsize coupe market and the most successful NASCAR racer. Now the storied Monte Carlo is taking its place among the legends of NHRA drag racing. Work began to develop GM Racing’s vision of a Chevrolet Monte Carlo Funny Car in the summer of 2003. The primary goals of the Monte Carlo marketing team and GM Racing engineers were to keep the shape and appearance of the new body as true as possible to the current production car, while adhering to the aerodynamic fundamentals needed to create a competitive race car. “A Funny Car body has to make a tremendous amount of downforce,” explained Terry Laise, GM Racing aerodynamicist. “The nitromethane engines create enormous horsepower, so you’ve got to have enough downforce to apply the power to the track. As the speed of the car increases, you produce more traction by taking advantage of the ambient air. You also need enough front downforce so that the driver can steer the car down the track. Obviously, you don’t want any more drag than necessary, but with the amount of power that is created, drag does not become a primary factor when designing the car. “A Funny Car body is so extensively reshaped that you could probably make a satisfactory shell out of most production cars – but we wanted Chevrolet’s new Funny Car to actually look like a Monte Carlo,” Laise noted. “We've managed to develop a race car that looks a great deal like a Chevrolet Monte Carlo but performs better than the cars we've raced in the past.” The first step in developing the new Monte Carlo was a performance assessment of the Chevy Camaro and the Pontiac Firebird, the two previous models used by GM Racing in NHRA competition. This included a vigorous, comprehensive aerodynamic comparison of how the two cars stacked up against the current competition in the Funny Car class. Working with Don Prudhomme’s Snake Racing Funny Car team, extensive research was conducted at the GM Aerodynamics Laboratory in Warren, Mich. Testing revealed that the five-year-old Firebird and Camaro molds (the oldest in Funny Car competition) were still very competitive. DOWNLOAD | X02MO_CH096
The science of aerodynamics has progressed since the early days of Funny Car racing when Bruce Larson competed with a nearstock fiberglass replica of a first-generation Camaro body.
“We knew we needed to make some changes, but it was good to know that we didn’t have to take huge strides with this development project to meet our goals,” said Laise. “Our technical notes, wind tunnel data and various feedback indicated we had to make minor adjustments to make the Monte Carlo better right out of the box. “I helped design the Monte Carlo body used in NASCAR, so some of the same technology could be applied to the Funny Car program. At GM Racing we translate and share technology among all of the racing series in which GM competes. Sometimes it's difficult to pinpoint specific areas, but you don’t forget what you did to develop one race car when you begin work on another. Although racing in NASCAR and NHRA Funny Car are two completely different sports, the laws of physics remain the same.” Through additional wind tunnel research and input from several Chevrolet and Pontiac Funny Car teams, improvements were made over the previous designs. Several attributes of the Firebird and the Camaro accelerated the development of the Monte Carlo body. For example, the dimensions of the Camaro and the Firebird fell short of the maximum dimensions allowed by the NHRA technical department. The Monte Carlo body was constructed to take advantage of these rules. The Camaro and the Firebird were also notably light on the front end, creating a slight front-to-rear balance deficit that at times made the cars difficult to drive. The new Monte Carlo body addressed these shortcomings, and with its refined shape and overall balance, a significant amount of aerodynamic efficiency was established without a great deal of additional drag. “The Camaro was an outstanding reference point when we began building the Monte Carlo,” said GM Racing director Mark Kent. “You want to have downforce, but you also want to have a good balance from front to rear. You want to have some adjustability so that the driver feels comfortable steering the car. Every driver has a preference on how much front downforce the body should produce – some drivers like it light, and some like it heavy so that they know when they turn the steering wheel, the car reacts. You also want to offset that with rear balance so that it coincides with each crew chief’s clutch setups on the car. Aerodynamic drag is also an important point to consider, but not nearly as important as getting the front and rear balance and overall downforce established on the car. “One of the areas we focused on was the greenhouse,” Kent continued. “Since we designed the Camaro, NHRA mandated a maximum height so we were able to take advantage of the production Monte Carlo’s roof shape. We brought it down by a small amount and tucked it in a little bit. That improves the airflow over the driver’s compartment all the way back to the box. We also shortened the overall length of the car by eight inches and ended up constructing the greenhouse to match the overall shape of the production car.” GM Racing engineers also incorporated new safety features in the Chevrolet Monte Carlo Funny Car body. The carbon-fiber body was made stiffer and therefore more stable. A larger burst panel was installed to allow greater dissipation of energy in the event of an engine explosion, and an enlarged escape hatch in the roof accommodates drivers wearing the HANS device. A wider windshield improves visibility. The burst panel on the Monte Carlo measures 576 square inches, twice the size of the NHRA minimum requirement of 288 square inches. The driver roof hatch opening measures 399 square inches, exceeding the NHRA minimum requirement of 306 square inches by more than 30 percent. “The Chevy Monte Carlo Funny Car is an outstanding race car,” Laise said. “The body is lighter, it’s stiffer, it’s safer and we know it’s aerodynamically better than the car we ran previously. The Monte Carlo Funny Car also retains the styling cues of the production version. The front grille area is very detailed, and the rear glass behind the door mimics the shape of the production glass. “We’ve managed to develop a car that looks a great deal like a Chevrolet Monte Carlo you would see in the showroom but performs better than the Funny Cars we’ve raced in the past. That’s great for GM and an important avenue for our company to promote our technology and high-quality products.” For Chevrolet and GM Racing, building a better Funny Car is serious business. ###