- Nothing to set up. Assetto Corsa publishes telemetry through Windows shared memory; StintLab finds the game on its own, whenever you start it.
- Every lap keeps its time, sectors and validity, a trace sampled every 5 m or so — speed, throttle, brake, steering, gear, rpm — the car, the track layout, the tyre compound and the driving aids.
- Not recorded: weather and temperatures, a circuit map, fuel and tyre wear.
- Each layout is its own track, and Assetto Corsa laps are never compared with F1 laps. Competizione is not on the supported list yet.
How Assetto Corsa telemetry works
F1 25 sends its telemetry over the network, which is why it has settings. Assetto Corsa does something simpler: while it runs, it keeps its live data in three blocks of shared memory — physics, graphics and session information — that any program on the same Windows PC can read. There is no setting because there is nothing to send.
StintLab looks for those blocks every 5 seconds and, once the game is there, reads them ten times a second. Start the game first or StintLab first; it makes no difference. Because shared memory is a Windows feature, this only works with StintLab on the PC you race on.
Assetto Corsa publishes no “distance round the lap” in metres, but it does publish how far round the lap the car is as a fraction, and the length of the track's racing spline. Multiply the two and you have distance — so an Assetto Corsa lap lands on the same distance axis as an F1 lap and charts exactly the same way.
What each lap records
| Recorded | Details |
|---|---|
| Lap time | Exactly as the game reported it. A lap time outside one second to one hour is a placeholder, not a lap, and is refused. |
| Sectors | Each sector time as the game completes it; the last is the lap time minus the others. If one was missed, none are kept — a partial set would mislead. |
| Trace | A sample every 5 m of track — or, above 180 km/h (112 mph), one per read, about 7.5 m apart at 270 km/h (168 mph): distance, elapsed time, speed, throttle, brake, steering, gear and rpm. |
| Track and layout | The circuit and its configuration together — Silverstone GP and Silverstone National are two tracks. |
| Car | The model, with the studio prefix on official content dropped: “Ferrari 488 GT3”, not “ks_ferrari_488_gt3”. |
| Tyre compound | The compound fitted for that lap. |
| Driving aids | Stability control, auto clutch, auto blip, tyre blankets, fuel and tyre-wear rates, mechanical damage and the ideal line. |
| Session | The session type and the game version. |
| Top speed | The highest speed of the session so far, as the lap was completed. |
How laps are judged
- Validity. The shared data StintLab reads carries no “lap invalid” flag. Rather than invent one, StintLab counts a lap as valid unless the game itself said otherwise during it — time spent in the pits, or penalty time added — and records which reason applied.
- The lap time is waited for. The completed-lap counter can tick over a moment before the lap time is written, so StintLab waits for a time that is present and different from the previous lap's, rather than reading a stale one.
- Replays and menus end a session; a pause does not. A replay would re-run laps already recorded, so it ends the session. Pausing is you taking your hands off the wheel, and you come back to the same session.
- A restart is a new stint. Restarting the session in place sends the lap counter back to zero; the new stint gets its own identity so its laps never overwrite the old ones.
What it cannot record
- Weather and temperatures. Assetto Corsa keeps them deep in the physics block, past the part StintLab reads safely. Reading further would risk inventing numbers, so conditions are left blank rather than wrong.
- A circuit map. StintLab does not read a car position from Assetto Corsa, so its laps have no map and no replay marker — the traces and replay controls still work.
- Fuel, tyre wear and pit stops. The strategy panel is built from F1 25's telemetry packets; Assetto Corsa laps show “Not recorded”.
Layouts, cars and fair comparisons
Every tool in StintLab works on Assetto Corsa laps: two-lap overlays, the braking table, theoretical best and the optimal lap, the practice plan and the season record. Two rules keep them fair:
- Each layout is its own track. A lap of Silverstone GP is never compared with a lap of Silverstone National, and your personal best is kept per layout.
- Two games are two tracks. An Assetto Corsa Monza lap and an F1 Monza lap are never compared, and never combined in your season record — merging them would invent a gain of many seconds.
Two notes on an Assetto Corsa practice plan are expected: “Game edition was not saved in these older laps” and “Weather was not recorded for these laps.” Assetto Corsa laps store neither, so every plan carries them. They do not mean anything went wrong.
Assetto Corsa Competizione
Competizione publishes the same shared-memory blocks StintLab reads, so in principle it records the same way. It has not been checked against the real game, and StintLab is not sold as supporting a game until it has been. When Competizione is verified, the waitlist email will say so.
Getting started
- Install StintLab and leave it running — closing the window keeps it recording in the tray.
- Start Assetto Corsa and drive. The tray badge turns green while it records.
- Open View → My laps after a few laps. Seeing nothing? Help → Setup check shows whether StintLab can see the game right now.
Questions
Do I have to switch anything on in Assetto Corsa?
No. Assetto Corsa publishes its telemetry through Windows shared memory by default. Start StintLab before or after the game; it looks for Assetto Corsa every 5 seconds and reads it ten times a second once it is running.
Why is my lap valid when I cut a corner?
Because the shared data StintLab reads carries no validity flag, so a lap counts as valid unless the game itself asserted otherwise during it — time in the pits, or penalty time added. If penalties are off in your session, the game says nothing about a cut, and StintLab cannot either.
Why is there no track map or weather for my Assetto Corsa laps?
StintLab does not read a car position from Assetto Corsa, so there is no map, and it deliberately does not read the temperatures, which sit in a part of the data where reading them risks inventing numbers. Conditions stay blank rather than wrong.
Does it record mod cars and tracks?
It records whatever car and track the game reports. Car names are tidied — the studio prefix on official content, such as “ks_”, is dropped, so “ks_ferrari_488_gt3” reads as Ferrari 488 GT3. Track names are built from the game's folder names as they are, so an official track can read “Ks Silverstone GP”. Each track layout is its own track.
Is Assetto Corsa Competizione supported?
Not yet. Competizione publishes the shared-memory blocks StintLab reads, but it has not been checked against the real game, and it is not sold as supported until it has. The waitlist email will say when it is.
Can I compare an Assetto Corsa lap with an F1 25 lap at the same circuit?
No. Two games are two tracks — different surveys, different cars, different physics — and StintLab keeps them apart everywhere, including the season record.