The Racing Line at Sebring International Raceway

Sebring International Raceway is a classic American circuit, and host to the 12 Hours of Sebring endurance race. There also seems to be some sort of anti-motorcycle culture in place, which means that only four wheel connoisseurs need apply for track time here. Sebring's main configuration is over 3.5 miles long and includes two large straights, as well as several other high speed sections where WOT through the turns is appropriate. The conventional racing line taken at this track by fast drivers is very close to that calculated by the genetic algorithm.

Look to maximize the radius through Turn 1 by not hugging the inside wall. Use the full track on the exit while carrying as much speed as possible. Turns 3 and 5 have very clear, late apexes, although they must still be approached smoothly with a good amount of trail braking.

Big Bend should be wide-open for just about everybody, after which comes the hairpin. The line through 7, 8, and 9 is similar for all vehicles - stay tight to the inside through 7, and at 7A only a smidge of leftward steering angle should be necessary to get pointed in the right direction heading toward Turn 8. The Fangio chicane can be taken at full throttle.

After braking down hard for Turn 10, the Miata carries more speed at the apex and exits much wider than the GT3 RS. Both vehicles take both apexes at Collier and stay just wide of the curbing at Turn 12 while setting up for Turn 13. Braking for Turn 13 is soft and begins near or slightly after the apex at 12. The racing line through Tower should be very round, approaching circular.

Bishop can be entered flat out, but a lift may be needed toward the second apex depending on tires and power level. Exiting Turn 15 the you should be slightly left of the center line before steering left at the apex preceding Turn 16. Leading up to Turn 16 there is a large amount of extra space on the left hand side of the track that allows for a much wider turn in - that extra area was not modeled in the simulation. Lower power vehicles like the Miata may benefit from using some of this extra space, but as you can see, the GT3 RS actually doesn't quite make it back to the left hand curbing before turning into 16.

Turn 16 presents the most ambiguity in line selection. The wall shape creates an odd inner boundary with several apexes to choose from. The Miata enters wide of the first apex, touches the leftmost apex in the middle of the turn, and finishes out wide of the last apex maximizing speed through the corner. The Porsche, on the other hand, touches three apexes: the first apex, the middle apex (same as the Miata), and the one immediately after. The exit it thus tighter and emphasizes acceleration back out onto the front straight.