Or a short lived engine.
yep, on a really bad day you might shoot a piston out the bottom of your engine or completely blow a cylinder.
That would be pretty much a write off of the engine.
When you run high compression or a supercharger/turbocharger you are flirting with detonation in order to get maximum performance of every cubic inch of the engine.
Detonation in a high out put engine usually ends up bad.