Telemetry

Strictly, telemetry means data sent from the car in real time; at track days, the word usually covers any logged data. A basic setup records GPS position and speed plus acceleration from motion sensors. Adding an engine data connection brings in RPM, throttle and temperatures. Race cars add steering angle, brake pressure and much more.

Data shines when you overlay two laps. Speed traces show where one lap braked later or carried more speed. G traces show how smoothly you transitioned between braking and cornering. Lining data up with onboard video adds context: what you saw and did at each point.

Avoid drowning in channels. Start with speed and lap time against distance, ask one question at a time, and remember each sensor's limits. An engine-data throttle reading, for example, is often the throttle plate position, not how far your foot moved.