Retepetsir
King of Subsonic
If you've got a mobile phone with GPS then you may be able to download and use this software:
http://www.racechrono.com/
Good for lap times (track days) along with 1/4 miles, etc. Seems pretty good to me so far!
http://www.racechrono.com/
Good for lap times (track days) along with 1/4 miles, etc. Seems pretty good to me so far!