Hello,
It seems that Insim doesn't send a packet at the 1st passage on the starting line of a hotlap (same for the 1st passage - at the start - during a race but less important).
How to detect the passage on the line to start the timer (for my Predict of Detect&Monitor) ? (if possible avoiding mci packet : info Node vs StartNode, because I stopped using them)

Hi.

Have you considered using the telemetry API to help you with this? There's no reason why you can't combine use of Insim and the telemetry API in a single program.

Use IndexedDistance and watch for the first zero crossing. You will need to use interpolation and knowledge of the track length to compute the exact lap start time. Linear interpolation works well enough in my experience, though there are more advanced possibilities if there is significant vehicle acceleration/deceleration across the start/finish line.

I haven't tried this personally in LFS, but I used this technique when developing a telemetry add on for Grand Prix Legends (GPL). In principle, it should work with any sim.

Hope the idea helps.

Or take data from game memory. It switch from 0 to 2 after crossing start/finish line.

Thank you for your answers and ideas.
The question was to validate that it was not possible in an official way.
So, I used a 3rd method = check current Node (I have it in memory) vs Start Node (I didn't find it in memory but I have it thanks to the RST package).