Open AiM .drk files without Race Studio 2

An AiM RaceStudio 2 .drk file starts with RDX and stores its samples at the end of the file, not after the header. Wild Telemetry decodes it channel by channel, verified against Race Studio's own CSV exports, and draws the track even though the file contains no GPS coordinates at all.

Format at a glance

Format at a glance

Extension	.drk
Vendor	AiM (RaceStudio 2)
Magic	RDX
Data region	Anchored at end of file
Scaling	Per sensor type, plus zero-offset calibration
Lap count	Header count equals Race Studio's displayed count
Position	Dead-reckoned (no GPS in the file)

Why is this format hard to read?

The sample region is anchored at the END of the file: it is found by subtracting the summed channel lengths from the total file size, because a variable-size, undocumented block sits between the channel definitions and the data. Any reader assuming a fixed offset lands out of alignment.

Decoding scale is set per SENSOR TYPE, not per channel. Wheel speeds arrive as km/h times ten, RPM raw, and GPS slope, heading and gyros as 1e-4-radian fixed point. Accelerometers and dampers additionally carry a per-channel zero-offset calibration. Getting any of those wrong breaks nothing visibly: it simply returns plausible, wrong numbers.

The product: FUJI

What you get when you open a session.

Fuji, coloured by how much time changes hands over each 50 m window between lap 15 (2:04.975) and lap 1. Neutral is exactly zero, the scale runs to ±1.12 s, and the 9 corners come from the stored layout.

What it does not do

The binary carries no beacon table. If you need the vendor's exact lap times, export the Race Studio CSV as well and upload it alongside the .drk.

If the session's heading never accumulates 300 degrees the track is not reconstructed, and we say so, rather than drawing a kilometres-long straight line.

Have .drk files?

Tell us which logger you run and we will say whether we can open your files before you install anything. Answered by hand.

Send us a file