Ask on the iRacing forums or on Reddit how to improve your driving and become faster, and chances are you’ll get Virtual Racing School as reply.
Virtual Racing School is an online service for data analysis. It uses the telemetry functionality of iRacing. A windows program logs the telemetry data and uploads it to the VRS servers. On the website, you can then analyse your laps. You can compare not only your own laps, but also to (very fast) reference laps provided by VRS. Below screenshot shows a comparison for turn 1 at Watkins Glen in the Porsche 911 GT3 Cup:
I lose around a second in this corner. It is quite obvious why – I brake earlier and longer with less maximum brake effort. The fast driver brakes later and harder, then feathers off the brakes as he turns in and gets on the throttle earlier. The lines are different, too – I turn in too late.
Analysing your weak spots like this can be very helpful in improving your driving and becoming faster. This is however not the only thing VRS offers. It also offers a driving academy, setups, the possibility to compare your laps to team mates, and even 1 on 1 coaching. The free functionality is limited to one analysis session a week, there are three subscription plans that offer more functionality.