Dodge Viper ACR
The American Club Racing (ACR) model was introduced in 1999. This model had suspension and engine enhancements focused on maximizing performance in road racing and autocross environments. Horsepower was, by the use of K&N air filters and smooth intake tubes, bumped to 460 hp (370 kW) in these models, while torque increased to 500 lb·ft (678 N·m). Weight was reduced by over 50 pounds (23 kg) by stripping the interior and removing other non-essential items such as the fog lamps (replacing them with brake ducts). The new stiffer, adjustable suspension removed another 14 pounds (6.4 kg). These models, which also have engine and handling modifications, has an "ACR" badge and 20-spoke BBS wheels.
Source: Wikipedia, 2011