aside from the weight differance, is there any visual differance between a S5 Turbo rotor and an S5 NA rotor? I was under the impression that the turbo rotors had a indeted faces and NA rotors were smoorth faced. If my belief is correct, then the NA motor that I just finished diassembling for my 91 NA had turbo rotors installed. If I'm wrong, then I learned something.

 

The T2 rotors will have a deeper compression bowl than the NAs. Post a pic of your rotors.

I don't know of any Mazda rotor that has completely smooth faces. The bowl is there to allow the flame front from the trailing plug to move into the lower part of the chamber... I hope that came out right. Its getting late.