The default time bonus for finishing a course within the 3X multiplier is 1500 points. The game then gives you 1 point per 100 milliseconds based on how much time is left in the 3X multiplier.

• Use this spreadsheet to easily figure out a specific score's in-game time.
• To interact with it, go to File → Make a Copy.
• Select the Hero and Course, then manually enter the score.
• Everything else is calculated automatically.

Here's a list of all the base max scores for all currently available heroes.

Recruit           | Agent             | Veteran
Mercy      7500   | Mercy      9750   | Mercy      7395
Reinhardt  7125   | Reinhardt  9810   | Reinhardt  9180
Sojourn    9510   | Sojourn    11715  | Sojourn    11580
Tracer     11640  | Tracer     11595  | Tracer     10710
Winston    10050  | Winston    10800  | Winston    13200