Neptunes
Ormeside,
Your Neptune sounds as good as it looks. And you had all the bells & whistles imaginable, too.
I never had to go through any tunnels myself, but I believe that in the (pressurised) B-29s there was always some anxiety in the tunnel about what might happen if the pressurisation failed at one end - but not at the other - and you became the slug in a giant airgun !
The Wright Compounds must have been one of the monster 4-row radials (the "corncob engines"). IIRC, they had to give up after four rows as they couldn't work out how to aircool a fifth. No doubt your turbos exhausted near the engines. In the P47 "Thunderbolt", a long exhaust pipe led from the Twin Wasp to the turbo in the bottom of the fuselage a long way back.
This caused much alarm and despondency among onlookers not familiar with type when you cranked-up, for the usual gush of flame, smoke and soot came out not where expected, but near the tail, and they feared the worst.
Danny.