Re-engineering a turbo-ramjet

Factual Questions
1

Look at this image of a Pratt and Whitney J58 turbo-ramjet:
63ae17a2b5962683ab44f80b9934b6d5.jpg (1180×831) (pinimg.com)

Specifically, the large tubes which bypass the compressor and turbine sections during supersonic velocities.

The thing about ramjet operation is…it only works at velocities above the speed of sound: supersonic air being “rammed” into the intake is compressed/heated by the speed of the air so it can sustain combustion.

What if we preheat these bypass tubes?

Re-channeling exhaust thrust, electric elements, nuclear, magic unicorn farts…
could artificially heating the incoming charge of air sustain a ramjet light-off lower limit at a more feasible sub-sonic velocity?

2

Heat is not the point. You need the ram pressure to raise the pressure in the combustion chamber and to provide a “cork” that make the results of combustion expansion go out the back producing thrust, not out the front producing anti-thrust.

3

Indeed.

The ram effect doesn’t replace the combustor; it replaces the compressor stage.