The front toe block adjusts front arm sweep. Larger amounts of sweep (like 2.0 or 2.5 deg) will give the car less initial steering, but more through the middle and exit. Generally it makes the car feel a little softer on the track. Smaller amounts of sweep (0.0-1.5 deg) will generally give more initial turn in, but less steering through the middle and exit of the corner. Basically feels a little stiffer on the track.