More power is always welcome.. ask any fighter pilot and he'll tell you.
A fully loaded Sukhoi will need it anyhow am not saying it need 380-400kn Right now but derated IZ 30 type engine for around 150 wet thrust and around 100+ dry will be gold. Also as the engine gets older and in general the thrust specially in varied Indian condition drops to 10-20 % . Sukhoi will be flying over sea to mountain and deserts as our dedicated attack jets armed with brahmos , other anti-ship missiles.
And an upgrade to engine is also to provide better fuel efficiency and maintenance which IAF seeks and IZ 30 engine for Su 57 is going to provide the same.
Infact that was what IAF asked in the first place but russian offered AL41 since IZ 30 wasn't ready. As of now it is developed and undergoing testing Once it enters serial production by 25 onwards we will be able to re consider based on what is offered.
Pilots will ofcourse demand more power but that's not the point.
Point is do su30mki needs more power to meet any operational requirements?? Which one and how much power??
Answer to these questions is given hal test pilot as no it has no shortage of power on operational front. Which means neither iaf nor hal is proposing engine upgrade only russian are proposing it for money.
Bramhos can only be carried by 40 odd su30mki which are upgraded for it that too only one bramhos weighting 2500 kg while normal payload for su30 is 8 tons+ . So even with bramhos in belly with more air to to air missiles (4-6) and fuel tanks to increase ranges to 2000-2500 km still su30mki will have payload to spare.
Other upcoming missiles are much lighter than bramhos like bramhos ng or rudram series and itcm based missiles.
Anyway no one carries full payload. 99% of mission are not more than 4-5 tons of payload even if heavy air to ground missile are carried.
Similarly su30mki speed is already much higher than most modern jets including Rafale , f35 etc. So even if it's speed comes down a bit it's no big deal also because it still has thrust vectors to dance in dog fights and it has now got mica ir type longer range CCM making dog fights rarer.
All in all engine upgrade is not on cards. Russian are pushing it because they don't have an aesa and without that what Value will they actually add??
