KAAN is designed to have significantly better stealth capabilities than the Su-57.
Who is NATO's enemy ? Russia, meaning it will face the SU-57
and the KAAN can compete with the SU-57; in fact, with the MUM-T concept
( KAAN + KIZILELMA + ANKA-III/IV ) will even be technologically superior to Russia
Radar cross-section estimates of 5th generation Fighter Jets and their sizes against living beings from smallest to largest:
Tarantula (Spider) ▸ -40 dBsm
F-22 Raptor ▸ -40dBsm
F-35 Lightning II ▸ -23 dBsm
KAAN ▸ -25 dBsm ... -5 dBsm target
Eagle (Bird) ▸ -20 dBsm ... -10 dBsm
J-20 Mighty Dragon ▸ -20 dBsm ... -5 dBsm
SU-57 Felon ▸ -10 dBsm ... 0 dBsm
Human ▸ -5dBsm ... + 5dBsm
To understand the real world difference lets take S-400's 91N6E Search radar as reference. According to the manufacturer 91N6E has a detection range of 390 km against a 4 m2 target. So it should be detecting , a F/A-18E Super Hornet (1 m2) from 275 km, the Su-57 (assuming 0.1 m2) from 155 km, and a F-22 (-40 dBsm) from 27 km.
In short, a Radar will be having between 6 to 10 times greater detection range against the Su-57 compared to F-22
KAAN utilizes a modern airframe geometry specifically engineered from the ground up to minimize its Radar Cross Section (RCS)
KAAN powered by 2 x GE-F-110 turbofan Engines (2 x 29,000 lb)
Why the Su-57's RCS is Higher Than Competitors
- Exposed Engine Faces: Unlike the deep, serpentine S-duct air intakes found on the F-22 and KAAN, the Su-57 has a direct path to the engine fan blades
- Manufacturing Fit and Finish: Closer look at production models and public airshows has revealed noticeable gaps between fuselage panels, exposed fasteners, and standard screws rather than seamlessly flush rivets
- Design Philosophy: The Sukhoi team prioritized extreme maneuverability and heavy, versatile internal payload storage over pristine, all-aspect geometric stealth
Radar
KAAN : MURAD-600A ( 2000+ GaN T/R modules ) .... 180-200 km against 1m2
SU-57 : NO36 BYELKA ( 1500+ GaAS T/R modules ) .... 140-160 km against 1m2
Low Priority Listening (LPI): KAAN's radar features LPI capability, making it more difficult for enemy aircraft to be detected by Radar Warning Receivers
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Professionals compared the radar detection ranges of the 5th gen SU-57 against KAAN based on estimated data
In a pure head-to-head clash over open airspace:
KAAN opens fire first while remaining completely invisible to the Su-57's radar.
RCS with the best possible acceptance
KAAN : 0.0030 m2
SU-57 : 0.0700 m2
RCS with the worst possible acceptance
KAAN : 0.01 m2
SU-57 : 0.1 m2
Radar Engagement
SU-57 vs KAAN : 25 km vs 102 km
MURAD-600A AESA Radar is based on detecting Aircraft with 1m2 RCS from 200 km
and RCS value from the frontline for X band 10GHz as 0.0030 m2 [ -25dbsqm ]
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Souce :
https://theaviationgeekclub.com/the...st-the-felon-compared-to-f-22-f-35-heres-why/
A source speaking to Reuters said that Gregory Meeks, a leading Democratic member of the U.S. House Foreign Affairs Committee and New York Congressman, did not approve the sale of F110 engines to Turkey. 
