Megan, An interesting read and just to add a few points :-
1] The B-29 R3350 was a carburetor engine and so I was told this was a source of the engine fires on that particular installation. Once the engine became a fuel injector engine the engine fire problem was much reduced.
2] The Wright R3350 in all cases was a supercharged engine where the supercharger was directly driven from the crankshaft via a high or low gear. It was not a turbo supercharged engine.
The turbo term was used when turbo driven recovery turbines [ 3 off] were fitted to the engine . These recovery turbines were driven by the engines exhaust and each one recovered about 60 hp [ Total 180 hp per engine] . These turbines returned their recovered hp direct to the crankshaft , but had nothing to do with the supercharger
Brit312