RS4@540hp vs RS4@436hp vs RS4@420hp
left RS4@436hp and original K04 turbos.
Middle has 540hp with K04 from RS6. Right RS4 is almost stock with a chip.
 Audi RS4 B5/B7
Audi RS4 B7 - B5
Audi RS4 B5 Stage3 vs Mercedes C63 AMG Stage1
Audi RS4 - stage 3 ~500hp
MB C63 AMG - ECU ~520hp