benefits of full ECU remap?

[M6 MIA]

hi all,
fell in love with the S5 and wondering something: i am told that since its the same engine and transmission as in the RS4 that software upgrade should allow getting at least 420hp. the only thing i notice is a lower red line on the tachometer. is that the only thng holding it back--some programming?? does anyone have info on this? i want to buy this car its absolutely gorgeous but it simply needs more power. someone help me on this so i can buy my first audi!!

[JLM]

I dont think thats possible .The rs4 engine has more power because of the internals they are different from the 4.2 v8 version in the s5 .The rs4 engine is a highly reworked model from the old 4.2 L V8, having cylinder-direct fuel injection and 4 valves per cylinder instead of 5. It produces a total output of 420 PS (309 kW/414 bhp), over 100 PS (99 hp/74 kW)/litre.

[AuditudeA642]

The RS4 engine has nothing in common with the old 4.2 or the S5's 4.2 besides them being them having the same displacement. The RS4 engine can be best related to the 4.2 offered in the Q7 but it's still totally different than all the other 4.2's.