How to stop engines from shutting down during overheating?

[ultraroblox]

All air-breathing engines overheat soon after reaching supersonic speeds and automatically shut down, even though I have "Ignore Max Temperature" enabled. All of my planes are unflyable due to this...

[FancyMouse]

You need to provide more info (screenshot of plane, mods installed, etc.). It doesn't sound stock behavior. The closest mod behavior I know is from KSP interstellar, where you'll have to add a precooler after your intake to not overheat the engine. But that limit is way beyond supersonic - e.g. rapier is ~1350m/s. Without interstellar, or with interstellar but precooler properly mounted, should be totally ok to reach 1.4~1.5km/s.

[ultraroblox]

Sounds about right, I have Interstellar Extended and that happens usually with rapiers. Its really a pain with SSTOs, but this time I'm only going 900 m/s and my ram jet starts to overheat.