The latest fifth-generation Su-57 fighters from early production batches will be equipped with advanced second-stage AL-51F1 engines. Currently, the aircraft fly with first-stage AL-41F1 powerplants.
Work on the AL-51F1 has been completed, the engine is ready for serial production, and integration into the fighter has begun.
After these engines are put into mass production, earlier-production Su-57s will be retrofitted with them.
Recall that the baseline AL-41F1 engines for the Su-57 have a maximum thrust of 8,800 kg, trailing the American Pratt & Whitney F119-PW-100 rated at 10,500 kgf by 16%.
Thus, the AL-51F1 in non-afterburning mode will provide Su-57M fighters with a sharp increase in supercruise speed to 1.9 - 2.1M. Currently, this figure reaches 1.6 - 1.7M. Afterburning thrust is 18,000 kgf.