Still if it take 1000hp to get 5000 its a good gain me thinks.
When Renault were running their turbo F1 engines (the monaco motor)they were getting in excess of 1300 hp from 1492 cc
So considering that the top fuel engines are around the 8000 cc mark and the F1 engine was running a derivative of petrol ( closely guarded by chemists at the time) not Nitro Methane.
Turbo charging is a better option only much more difficult to package due to it having to be connected to the exhaust, oil feed and some types coolant to operate and be fitted in the most confined area of a road car.
Still having said that there are superchargers available that are basically belt driven turbo's and these require less power to drive them than the older ROOTES type
regards Kermit