How SRT Validated the 204-mph Top Speed of the Charger Hellcat

Wednesday, January 28, 2015

How SRT Validated the 204-mph Top Speed of the Charger Hellcat

From the February 2015 issue of Car and Driver

Modern computer design tools can accurately predict a car's EPA mileage, number of crash-rating stars, and top speed even before the first prototype is constructed. With several supercharged models knocking on 200 mph, simulations based on wind-tunnel studies are the preferred means for avoiding the risky business of actual top-speed measurements. Also, topping 190 mph on any U.S. automaker's test track is difficult due to the tire scrub inflicted by their steeply banked corners.

Enter Erich Heuschele, the SRT vehicle dynamics engineering manager, who wouldn't settle for a number generated by a simulator. Heuschele hustled the Dodge Charger SRT Hellcat to a 204-mph two-way average on the 7.5-mile banked oval at the Transportation Research Center (TRC) near Columbus, Ohio.

2015 Dodge Charger SRT Hellcat

Heuschele, a champion amateur road racer and veteran Viper tuner, admits that his trip to the outer reaches was a riveting experience. "Driving 10.2 miles flat-out at TRC for 183 seconds definitely got my adrenaline flowing. I was shaking when I stepped out of the car after the runs." Except for a bolt-in roll bar, a racing harness, and a fire-extinguishing system required by TRC, Heuschele's Hellcat was stock. The tires were inflated to 40 psi to resist the extra loading imposed by the 28-degree banking. Three radar guns, VBOX test equipment, and one Harry's GPS LapTimer recorded data. A medevac helicopter was on hand just in case.

Farther north, Cadillac warmed up the CTS-V on the 4.5-mile banked circle at GM's Michigan proving grounds. One prototype topped out at 197 mph, held back by the tire scrub resulting from cornering at a steady 0.35 g. To prove that the car was good for more, GM engineers John Buttermore and Brian Wallace made the trek to TRC. Their test car ran 201 mph with the wind. But into the wind, the highest speed achieved was . . . 197 mph. That's a two-way-average top speed of 199 mph. But we'll give Cadillac the 1-mph break because we trust it will continue CTS-V development until the car is capable of topping 200 mph on a calm day.