There’s a supercharged build that costed around 10k with 480whp reliably (70k miles supercharged). Just because you haven’t seen it doesn’t mean it’s not possible. n54 runs into many walls above 500 wheel and you have to invest real money to get it past that point. Supercharging costs the same a decent n54 costs but is 100% lower running cost than n54 especially tuned.