Honestly on the road, I don't see people needing more than 350-400bhp in a car like an Impreza or an Evo. 99% of cars on the road will get toasted with that amount of power through bends and on the straights. In smaller chassis where the power won't go down so well, 250-300bhp in something like a Focus again, imo is good enough. But agree you need handling to go with the power. Mine has GAZ shocks all round, and fully polybushed front and rear. I've upset plenty of smaller engined BMWs, Audis and Mercs before.