Recommended GPS Setup
RaceTrace relies on GPS to record your position around the course. The iPhone's internal GPS provides reasonably accurate lap times, but often does not produce accurate speed vs. distance graphs. We highly recommend using RaceTrace with an external GPS device.
It's important that the GPS has a clear view of the sky. This means the GPS should not be in a pocket or glove box, but mounted outside the vehicle. If the iPhone's internal GPS is being used, the iPhone itself needs a clear view of the sky.
We've tested several external GPS receivers. Our current favorite is the Bad Elf Pro. It's a 10Hz unit with logging capabilities, meaning you don't need to take your iPhone out on the track. You can import data into RaceTrace when you get back to the pit. It connects via Bluetooth, so no cables or computer are needed! This is especially useful for kart and motorcycle riders where vehicle mounting space is scarce.
The Dual XGPS150A is another good choice. It's less expensive because it's not a logger, but the GPS accuracy is great.
Please let us know your experience using other GPS devices.