http://www.mariokart64.com/mkdd/ Here you can see the leaderboards for Time Trials. The site looks outdated, but it's still very active. I recommend checking out the standards: http://www.mariokart64.com/mkdd/standardc.php to see which standards your Time Trial times are. Another thing to keep in mind is that 50hz is allowed for Time Trials, and that there are 3 rankings: Combined (50hz and 60hz), 60hz rankings, and 50hz rankings. If you have any questions (for example how to submit times), feel free to ask in the MKDD discord: https://discord.gg/zhzfxZg