DAGChamp Car World Series acronym for "Data Acquisition Geek," a computer expert who maintains a team's Data Acquisition system and analyzes the data. Teams use sophisticated sensors, transmitters, computers and software to provide information regarding the car and the driver actions, or inaction. Everything from engine stress to the driver's heartbeat can be monitored. The information is analyzed to improve handling, performance and even driver technique. Data can be acquired by connecting a computer to the car or by wireless telemetry.
DEEP STAGETo roll a few inches farther into the beams after NHRA-race staging, which causes the pre-stage lights to go out. In that position, a driver is closer to the finish line but dangerously close to a foul start.
DIALING INThis refers to the driver and crew making setup adjustments to achieve the car's optimum handling characteristics.
DIAPERAn absorbent blanket made from ballistic material, often Kevlar that surrounds the oil pan to contain oil and parts in case of an engine explosion; required for Funny Car and Champ Car World Series cars.
DIFFUSERThe bodywork at the rear underside of the car that controls underbody airflow as it leaves the back of the car. A good diffuser generates significant downforce.