I used to work at Inwood & Beltline, right off the end of the runway. It was great when the warbirds would fly in, but the B-17 was something else! It was so big and nasty on takeoff that it shook the building to the point stuff was falling off shelves. I can only imagine what Fifi would do.
Just imagine what they would be like with WWII grade fuel instead of 100 Octane. They don't produce near the rated horsepower they otherwise could. I can only imagine a 1000-plane raid forming up over England. Wow.
I was in the grass beside the runway at Airsho' one year when "Fi,Fi" took off. You could feel the vibration of those engines when she went past. A sort of out of rhythm thrumming that is hard to describe. Freakin' awesome.
I've read the B-36 was insane in that regard.