Paul,
What about this for the F1 Rocket. Turbo under the engine.  Forward
lower cowl air inlet ducted thru intercooler, larger duct to and around
turbo and exiting / ejecting aft lower cowl, with air exiting from rad
and oil cooling.
Would this be more efficient and help with cooling the turbo?
Dave D.

You have to be real careful about placing a turbo too low.
A major problem is oil drain back out of the turbo. It should be mounted
Well above the oil level in the oil pan. Either that or it gets real
complicated with a scavenge pump.