mike,
you should check the JB130!!
It is not only the thrust it is real power.
The exhaust gas leaves the nozzle with a very!! high speed.
that makes the speed. not only the thrust.
if this speed doesnīt fit into your reality I canīt help you.
but it is for sure.
do you know Ilja Grum?
He has seen this thing. Ask him.
do you know how drag behaves?
you need approx. twice as much power to be 50% faster. this is the case here,
look carefully. the fins a at the last one are smaller and the space between the fins is bigger. this result in less induced drag.