How Stock Car Telemetry Works

Testing Stock Cars with Telemetry

Before a race, a NASCAR team has a limited amount of testing time on the track -- five two-day tests, and five one-day tests. So the team wants to use that time to gain as much information as possible. It might install as many as 60 sensors on the car [source: Wise]. The team will check several things, such as:

  • Shocks
  • Throttle inputs
  • Tire pressure and temperature
  • Airflow over and around the car
  • The frame's distance from the ground (measured with a laser altimeter)
  • Suspension (measured with actuators, or valves, attached to the chassis and wheels)

An antenna on top of the car broadcasts the info back to the pit crew's computers. Or, the car's own system collects the information so that engineers can download it later using a relatively familiar piece of technology, a laptop running Windows [source: Kushner].

­The team, which consists of engineers and automotive technicians, coordinates test information with wind tunnel data about the car's air resistance, both alone and in combination with other cars (see How Stock Car Drafting Works). The team members also gather data about the track surface and conditions so that they can tune the car to that racecourse.

Of course, all this happens before the actual race. In the race, although the pit crew might have a race engineer, communications between the driver and the pit crew are limited to analog technology.

And that might be a good thing. Telemetry is allowed in Formula One races, and it is part of why those cars and teams are so astronomically expensive. In 2005, a Formula One team might spend around $200 million, a sharp contrast to the $15 million spent for a NASCAR team [source: Wise].

More importantly, NASCAR feels -- and many fans agree -- that too much telemetry can take the fun out of racing. "Keep our athletes athletes," is how Nextel Cup series director John Darby puts it [source: Wise]. As athletes in every sport rely on increasingly sophisticated technology, it's likely that eventually Darby is going to have to be more specific.

To learn more about stock car racing and related topics, visit the links below.

Related HowStuffWorks Articles


  • "Afar radios provide wireless data telemetry to enhance TV coverage of NASCAR and Indy 500 racing events." Afar communications. (Accessed 1/8/09)
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  • "Kentucky Speedway -- Franchitti Test Day Summary." (Accessed 1/7/09)
  • Kushner, David. "NASCAR Waves Techies Away from Track." New York Times. 2/11/1999. (Accessed 1/8/09)
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  • "M3 Suspension Telemetry Data." European Car Web. (Accessed 1/7/09)
  • Maloof, Denise. "The New Frontier." Sports Illustrated. 2/29/2002. (Accessed 1/8/09)ht­tp://
  • Meserve, Jason. "Keeping track of NASCAR." Computer World. (Accessed 1/8/09)http­://;395727197;fp;16;fpid;0
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  • "What is an actuator?" wiseGEEK. (Accessed 1/8/09)
  • Wise, Jeff. "NASCAR Goes High-Tech." Popular Mechanics, 3/2005. (Accessed 1/8/09)


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