A new leaderboard would be pointless. It would only benefit members of this forum and serve as a ranking system. For instance, fastest ACR many people know of is running 8.980s, but I run with two individuals who have 8.905 and 8.8xx tunes on their ACRs. No aids, no skid. They race them online and it is completely legit. I spent an hour with them asking questions and watching in order to believe it, but it is real.
You want to have fun? Forget the leaderboard. Racing and tuning is the fun part.
Btw* 8.9xx is possible with the Spec V GTR