You could try it in deep space I guess. By that I mean anywhere after 5 gigameters where Kerbol no longer has gravitational influence, or doesn't appear to anyway. I think the maximum G force anything can possibly take in KSP is ~25, because that's the limit on the interface thingy.
The only thing for certain is that full acceleration with anything over 1000 thrust rips the ship apart, and my Super-Engine with 6000 thrust can go no more than 1/10 throttle before the engine explodes or falls off or something.
However, flying directly into the sun makes you fly off at higher than lightspeed in an apparently random direction, so you would utterly destroy any ship you tried this with but the effect would be the same.
In short, device = sun.
