Thanks for those nozzle diagrams Dude, they are very useful to visualise what's happening.
I remember reading Stanley Hookers book "Not Much of an Engineer" (I know the feeling
), in which he explains how at Mach 2 the Olympus is only providing about 8% of the total thrust but then goes on to say that at the low speed end of the take-off run it was 100% of the thrust so his designers were not let off the hook. That falls to 82% in subsonic cruise.
Ah, found the figures for Mach 2, the inlet provides 63% of the total thrust, exhaust nozzles 29%. That certainly explains why the thinning and re-profiling of the inlet lip was so important to improving the fuel burn, and hence range.