We have all been in the following situation during a race weekend:
We start off really strong during the first practice session and are encouraged at how this weekend might go. We go back out for practice two and we go faster, but everyone else goes even faster. Then over the next few sessions we continue to drop further and further behind the leaders. What is happening?
Well, as Ryan found out the most likely answer is that the leaders are adapting their lines to use the rubber being laid down to their advantage while you don't adjust enough.
We know the rubbered line is the "grippy line" but that doesn't mean we want to place the center of the kart over the middle of the rubbered line around the race track.
Instead, we use some inspiration from motocross riders and how they use ruts. They let the outside of the tire get up on a rut and use the rut to help rotate the bike to get out of the corner.
In a go-kart we want to get underneath the rubbered line and have our outside tires get out to the rubber after we turn in and are headed towards the apex to help rotate the kart.
What tends to happen is that as more rubber is laid down on the race track, we can turn in earlier. When we turn in earlier we don't need to turn as aggressively which means we can roll in more entry speed into the corner. They key here is that an earlier turn in does not mean an earlier apex. We want to continue to apex in the correct position but turn in slightly earlier as the weekend goes on.