1) Why not just put a regular turbo on and agree to not over boost it?

That's what a turbo normalizer is - except that the agreement is made
with the Grand Canonical Ensemble, which enforces the agreement for you.

If the outside of the cylinder is 20" [pressure]

I don't think the outside pressure matters. Unlike with (say) the cabin
of a jetliner, the outside pressure is =not= helping to hold the engine
together. The strength and thickness of the material is. There could
be a vacuum outside and it wouldn't matter. (well except to the extent
that there's no oxygen in a vacuum

Jose
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