I help build and crew on 2 different cars, an outlaw dirt modified and a winged 360 sprint car. Has this system been used on any 1/4 mile or 1/2 mile circle tracks. How accurate would the system be without the use of a "high quality" GPS signal? We would only be able to use the phone's internal GPS. What is required to add the tracks we race at?
Thanks you for the info.
Not sure how good the data will be with internal GPS especially on a race car (G forces tend to be higher). Good way is to do a session and check how the plot on "Traveled route" view looks. If the laps are fairly consistent looking then the lap times should be accurate. If the laps are just mess or zig-zag, then the lap times are bad or even worse do not register.
5 Hz GPS like the QSTARZ BT-Q818X cost anywhere from $40 to $80 so I would not save on that.