Data acquisition has completely changed racing, and now that focus on numbers is starting to seep into regular road cars. Chevrolet kicked off the trend with its Performance Data Recorder, but now Porsche is offering its own product based around a smartphone app.
The Porsche Track Precision app is part of a special version of the Sport Chrono performance package exclusive to the track-oriented Cayman GT4, 911 GT3, and 911 GT3 RS. It combines vehicle data with video and lap times generated by an attached smartphone's camera and GPS to give drivers ways to analyze their lap times.
The app itself can be downloaded for free from the iTunes Store or Google Play. It includes maps for 60 race tracks; others can be added using a map editor, or by driving a lap with the system turned on. Once the track is selected, the driver secures the phone to a windshield mount.
Recording starts automatically once the car passes the start line. The app monitors steering angle, pedal positions, speed, longitudinal and lateral acceleration, and sector and full-lap times. It also shows deviations from an ideal reference lap using a virtual "ghost car."
Much of this information is drawn from an onboard control unit which sends data to the attached smartphone via WiFi. Transmissions occur 10 times per second and include a "high-precision time stamp," which Porsche says helps ensure accuracy. Drivers can also switch between their phone's GPS, the car's, or an external unit if they desire.
The system also includes pre-wiring for a "lap trigger" that must be purchased separately from Porsche Tequipment. This is meant to provide more precise lap timing by using a transmitter placed at the start/finish line and a receiver mounted on the rear side window to mark the start and finish of individual laps.
Cayman GT4, 911 GT3, and 911 GT3 RS owners who don't buy the Sport Chrono package can also have their cars retrofitted for the Track Precision app and its addenda by Porsche Tequipment.