Try to turn in a little later and your clipping point will be further in the apex. By braking and turning in later than usual youll be able to accelerate earlier and get a higher exit speed. But if you turn in too late youll be having a hard time not to drive right off the track. This obviously kills corner exit speed completely.
If you delay braking by just a fraction later than usual, you wont be able to make it onto the shortest route (normal racing line). So instead you take the late apex line, as shown in the illustration above. Its a longer line, and you need to brake a little more, but the big advantage is that you are able to get on the throttle earlier.
It's usually better to sacrifice some entry speed in order to gain some exit speed. This is especially very useful in case there's a long straightaway after the corner. The difference of 2mph in corner exit speed will result in a 5mph difference, or even more, later on the straightaway.
So the exit speed is compensating more than enough for the loss of corner entry speed.
Slow in, fast out!
Hitting The Apex
Its possible that you are finding it difficult to compensate for the slip angles. If you never seem to be able to hit a particular apex because the tires wont steer where you want to go, you can help yourself by shifting your focus point.
As youve learned in the basics of racing, as a general rule you go where you look. So you can try looking a little further behind the apex, for about the same amount you want to correct your steering.