Panagiotis Atmatzidis

a digital diary

Track Day 061214

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The race

This weekend I had the pleasure to take part on another track-day at Serres circuit. The track-day wasn’t all that good, because of the rainy weather and the poor conditions of our car. The tyres where gone and we were basically on continuous slippery slop while on track. The first day, which was the most rainy, I’ve managed not to lose car control, but my laps were pathetic. Really I had no idea I could go that slow.

The second day for me was even worst. The elise is a particular car in the sense that the oversteering in wet conditions happens at once and most of the time there’s not much that you can do. When the car starts to go it usually goes, before you can put yourself together. If you touch the breaks you’re gone for good. Anyway, the thing is that the car needs a very good service before undergoing any more track-days plus we need a new pair of tyres.

To give a hint of how slow we were racing1… At the same track my best lap is ~ 1.38 minutes and my father’s best lap is ~ 1.36 minutes. Today my best lap was 1.58 while my father managed to run on about 1.52. If you stop and think, it’s about 15 seconds slower on a 3.2km track per lap!

Recording the laps

However, I had the pleasure to test Harry’s GPS laptimer. This is an amazing iPhone application to record laps. Below you can see some footage of this amazing iPhone application. What left me most astonished was the range of iPhone abilities this little application manages to handle! It keeps data via the internal accelerometer and GPS! At the same time it records the video, low or high resolution depending on your choice. Then the application creates a video like the footage below, overlaying the data into the video inside the application. Apparently iPhone has some sort of hardware acceleration which makes the video creation procedure blazing fast for a mobile device!

I will buy an OBD WiFi adapter and an external GPS tracking device to record our laps more accurately. I had the opportunity to compare the GPS results with the track’s own lap timing system and I’ve found gaps ranging up to 2 seconds the first day and up to 0.3 seconds the second day. However, I believe that once you use a dedicated GPS device, the results will be accurate enough for amateur track-day driving! The OBD will give me more data like throttle, gear, etc.

The data is extremely important to analyze later your results later and visualize possible mistakes, points where acceleration or speed are not optimal, bad lines and so forth.

I was really amazed by this little application. I never expected an iPhone alone to be able to handle all these things, I knew it was theoretically possible, but it’s one thing to know and another to witness, right? :-)


  1. I say ‘we’ because I always drive with my father :-)