Before a race, increase the downforce and soften the suspension in the garage. You will also have to increase the ride height in order to keep the frame from touching the ground. Slowly introduce any changes in momentum and velocity.
Pay attention to other drivers to learn the circuits. Start at a non-championship race at Ace level. Start a free-practice session and when in the pits, move your view between the various drivers. Locate a decent driver (for example, the first McLaren driver that comes along) and watch how they drive the circuit. Take notes over several laps, while paying attention to their speed and gear at each corner.
Use the following gear settings to be a little slower exiting very tight corners (any corner you need to drop down to first gear for) and quicker exiting faster corners. Your acceleration will be much improved from about 100 mph upwards.
Sixth gear - Set the sixth gear for the fastest part of the circuit, making sure that the final rev counter light comes on. First gear - Set your first gear quite high, depending on the actual circuit. Use a value of 28 to 30 for slow circuits and over 32 for fast circuits. Second gear - Leave a large gap to second gear. Use a value of 7 to 8 for slow circuits and 10 for fast circuits. Third, fourth, and fifth gears - Set them at even intervals between second and sixth gears. If the gaps have to be un-even, make the largest gap between second and third gear. Ideally these gaps should be about 4 or 5, although this may be higher on fast tracks.