These videos were taken using the iPhone application, Harry's Lap Timer, on November 10th, 2011 at the Meadowlands autocross, hosted by MotorsportsNE. The Hamfist Racing Mazda RX-7 won top honors, as the Fastest-Time-of-Day, with a lap time of 60.705 (click here for the complete results). Harry's Lap Timer integrates racing data-acquisition through the iPhone hardware (GPS and accelerometer) and iPhone high definition video to allow for video-data-overlay. The program is not bad for a $19 application. After this first go-round with the program, it became clear the sampling rate was too low to provide any useful data for autocross application. It needed additional hardware support so an Emprum GPS module was ordered. The new unit will provide 5 hertz sampling rate. This will take five times as many data samples as the original iPhone GPS internals (1 hertz - illustrated in the below videos). Keep tuned to www.HamfistRacing.com for updates and reviews for the Emprum accessory GPS module and it's integration to the iPhone application, Harry's Lap Timer in 2012. Hopefully this program can become a new tuning (and driving) tool for the Hamfist Racing team.
Note: Video #2 has an accelerometer error (reading force of gravity after reorienting the phone)