You won’t see the benefit to run case vacuum to promote ring seal(using low tension rings) until at least 12-14" hg, and you can’t get that running off an intake manifold or turbo inlet while the engine is under any sort of useful load… If you’re pulling more than 1-1.5"hg in your inlet tube, you have a clogged air filter.
that’s why people with big HP doing this either run a separate belt driven vacuum pump, or a dry sump system with roots scavenge sections that create case vacuum.