This two birds of pray can't be compared performance wise simply because J 20 is a bomber,not an air superiority fighter and PAK FA will be a multirole air superiority fighter.So PAKFA will definately have advantage in air combat.Pakistani and chinese members here complains about the straight engine air intakes and the underbelly of PAKFA.But they deliberately forget that the PAKFA tds are not fitted with the internal weapon bays,the YF 23 also had angled belly but still was stealthier than F 22,and it is not necessary to have s shaped air intakes to shield the engine fanblades from radar waves;radar absorbing composite mess can do the job with same efficiency at a much reduced cost and shaping.Example-the Silent Eagles achived same degree of frontal stealth as JSF by that technique.
Meanwhile,the members also praise and claims superiority of J20 because their DSI inlets.Though DSI reduces rcs but also seriously hampers the aerodynamic performance of the fighter.DSI fighters can't fly at greater speed of mach2 and can't turn more than 9g turns.Moreover J 20 has big canards and there are no better ways to sacrify stealth than adding canards on a frame.But PAKFA will definately achieve much greater agility
with 3d tvc and the LERX without increasing rcs.Besides the J 20 will be under powered because it is a much bigger and heavier platform than PAKFA but will use engines with same power output.So in air combat J20 will be definately in disadvantage against PAKFA.
REGARDS....
Meanwhile,the members also praise and claims superiority of J20 because their DSI inlets.Though DSI reduces rcs but also seriously hampers the aerodynamic performance of the fighter.DSI fighters can't fly at greater speed of mach2 and can't turn more than 9g turns.Moreover J 20 has big canards and there are no better ways to sacrify stealth than adding canards on a frame.But PAKFA will definately achieve much greater agility
with 3d tvc and the LERX without increasing rcs.Besides the J 20 will be under powered because it is a much bigger and heavier platform than PAKFA but will use engines with same power output.So in air combat J20 will be definately in disadvantage against PAKFA.
REGARDS....