Protagonist is a young underdog racer competing against others. Much of the story is about competition, and takes place in the pit spaceship hangars. The racers each have ramjet ships. The race course is an oval 'groove' of space the size of a solar system, which was created in distant past by an alien civilization for reasons unknown. I think the special space in the groove enables faster than light racing.
Imagine an entire solar system designed as the most awesome racetrack in the history of the sport. Imagine personality-implanted robots, whose knowledge and influence can make or break a racer's career, and fusion-fueled ships that move at extraordinary speeds. Imagine a young hero from Earth, braving the unknown to reach Clypsis, where his dream of being a faster-than-light racer can come true.
Protagonist does drive a ramjet-like ship (using your opponents fumes is a tactic).
Middle of the track is faster (makes it harder to pass).
Protagonist does spend a lot of time modifying his spaceship to go faster, so mentions of the pits.