>> that M53 dry thrust is some 15% more than the F414.
an interesting article comparing various fighter engines though not the M53.https://defenseissues.net/2014/12/06/fi ... mparision/
maybe the M53/M88/EJ200 with low bypass ratios are optimized for high alt and high dry thrust as a % of wet thrust - trading off a bit of fuel economy - a necessity for air to air missions to sustain nearly supersonic speed for longer periods. the 404/414 were designed for F-18 which operated mainly at medium level for strike and not so a2a oriented initially because the F-14 was there for the long range counterair mission...now after super hornet 414 design changes it has caught up with the euro engines...... the F135 engine still has 2X the bypass ratio of the M88 ... both a factor of the large engine size able to keep things moving with 50% air and perhaps need to meet the 900 mile combat radius range so fuel economy is important.
the fighter with the highest bypass ratio still operational is the RR RB199 on tornado with 1.1 - flies fast and slippery in the low alt DPSA mission https://en.wikipedia.org/wiki/Bypass_ra ... ass_ratios
at other end we have ratio 12 on the latest geared turbofans with the huge fans on civilian planes. fuel sipping to the core with > 90% bypass air.
engine design seems like having to balance some 100s of interlinked factors in a house of cards , meeting the use cases and somehow getting a design that is still reliable and maintainable over long term.
no wonder only a few countries with the deepest STEM resources and dozens of engines under the belt (so biggest historical data bank of design choices) run the show.
time seems to be its own teacher, and hard lessons are also learnt from operational experience only - cheen has taken some slaps in their efforts to quickly close the gap, but they are persisting and putting 1st gen engines into flying duties and gathering data banks which kaveri can never gain sitting on the ground in a static testbed....just as ISRO is still taking blows and learning hard lessons on lab vs inflight failure modes.
we need to get kaveri into a couple of Mig29U or Su30 and atleast start this long journey. HAL should pay itself to produce a couple more Su30 and engage retiring pilots onto flying this testbed, and equip the WSO station with the engine monitoring kit.