What is actually in a RaceBox CSV
The header block, the channels, the sample rate, and the two gotchas that make most people's lap plots wrong.
Corner IQ started because I wanted to look at my own laps without paying for a subscription. The first job was understanding the file the RaceBox Mini writes.
The header
Before the data table there is a small block with the track name, the configuration, the number of laps, and one line per lap with its time and sector splits. Most importers throw this away. Keep it: it is the only place the lap times are official.
The channels
Each row is a 25 Hz sample: a record number, an ISO timestamp, latitude, longitude, altitude, speed, G-force in three axes, the lap number, and lean angle. The axis names are the first gotcha. The channel labeled X is longitudinal on the bike (braking and acceleration), not lateral. If you plot X as cornering force your traction circle is rotated ninety degrees.
- 25 Hz means one sample every 40 ms. At 150 mph that is about 9 feet between points, so braking markers are only as precise as that.
- Lap numbers restart at the timing line. The first partial lap is out-lap; drop it before you compute a best.
- Speed is GPS speed, so it lags a hair under hard braking. For brake point work, use the longitudinal G channel.
What the demo does
The Corner IQ demo on this site reads the header for track and lap times, treats X as longitudinal, colors the GPS trace by speed, and reports the session numbers: best lap, top speed, peak braking G, peak lean. The sample is my best lap from NCM Motorsports Park; drop your own CSV on it and nothing leaves your browser.