Hey there,
First:
Standard 6.6 is not really do-able. More like 6.8
Second
Now, there is some other thread where we talked this over, realise a 0-60 isn't a proper comparison to begin with, too many factors are involved... (traction, tire temperature, weight, shifting...)
Now, if you really insist, let's say a 5.7 might be possible, (
My estimate, can't confirm!!) if traction is sufficient that is.
However, don't compare power upon 0-60...
eg.
280BHP EVO IX: 5.7 (4x4 drive)
420BHP M3: 5 sec flat
560BHP Lexus LFA: 4sec flat
You have double the power on a LFA than an EVO, only 1.7sec faster...
My point is, BHP is pretty much worthless under 60Mph.
However, greater difference will be seen above 60Mph... MUCH greater difference I assure you