Thank you, my Bro. Your support amidst the strenuous or hysterical objections of Butt Gang boys (菊花党) really helps.
According to my calculations, if J-20's empty weight is of 22 tons (2 more than F-22, because its body, nose to nozzle, is 10ft or 3m longer), and carries 3 tons of fuel for the testing or demo (25 tons total), assuming dry thrust is 60% of max thrust, it will requires the engine to have > 212kN of maximum thrust, to left the J-20 in an effortless 90 degrees, vertical climb, without the use of afterburner,
WS-15 has already passed 180kN, IMO, and may have already hit 212kN. This is shockingly more powerful than even the most patriotic Chinese, has predicted. But it's really not that surprising, because WS-15 is rumored to be based on the YAK-141's powerful R79-v300 engine, which was rated as 206kN. That was developed in the 1980's by the Soviets.
It is not beyond belief, because F-35's F135 engine is rated as 196kN, probably under-reported by 10-15% to protect the maximum performance secret. And it's been in production for 10 years already.
I think we have underestimated the WS-15, because the idea that China can't do aircraft engine has burned into our heads.
China's strict secrecy regarding WS-15, and intentional deceptions through the Internet Forums, doesn't help either. China has really got everybody fooled this time. China lived up to its reputation as Master of Deception.
PLAAF knows very well, the engine makes a plane. One must guard the true performance of the engine jealously, because, the performance envelope of the whole plane could be easily approximated using wind tunnel testing and software simulation, once its engine performance is determined.
.