To elaborate further on relationship between F1 and fighter engines, let's look at two WW2 era mechanically supercharged V-12's made by the same company with some of the same technology and probably some of the same engineers.
Mercedes F1 car, 1939, 480 bhp, 3 liters, 160 hp/l
DB601, 1939, 1175 hp, 33.9 liters, 34.7 hp/l
160/34.7 = 4.62, ratio of specific output of F1 engine to specific output of fighter engine.
The factor of 4.62 accounts for the fact that the F1 motor had smaller displacement (specific output generally decreases as displacement increases), ran on much better fuel, and only had to last 2-3 hours rather than hundreds of hours, was hand built, and had a production run of 10-12 rather than 10,000 or so.
Back to the 1980's turbo F1 example, let's say 1,000 (reliable) hp from 1.5l. 1000/1.5 = 667 hp/l
Derate by a factor of 4.62 to get to a figure for aircraft -> 144 hp/l
Multiply times displacement of notional modern piston fighter engine (let's use 33.9 liters of DB601) -> 4,890 hp.
So something like 5,000 hp.
A lot less than my 15,000 guesstimate above but nothing to sneeze at. In either case I think we are looking at way more horsepower than any WW2 fighter prop system could handle.