In "spec" racing leagues like gp2 for ex, you can make suspension and wing adjustments but the chassis and engines are all the same. Something like this is what i mean. You would have to rely on the honor system not to use power limiter, but I don't think that would be a problem at all.
No assists at all, no penalty, realistic settings,GTP rules.
Tracks, cars and laps are all negotiable just fun clean racing is what this league should be about
Edit, clearly I said your own cars so u would be able to adjust settings, not online garage.