You'd have to bore out and increase displacement to at least 2.0L-2.1L to reach 250whp on a streetable N/A B18C1.
With big N/A setups you don't see many dyno postings because the numbers are never really big. What you do see is impressive track times which is all that really matters. Peak horsepower numbers equal, N/A will usually display the superior engine transient response time to F/I setups. That's why N/A numbers are never nearly as big as F/I setups yet they pull close numbers at the track.
Of course, tell the F/I guys that and they'll just complain about traction all day long
Not that I'm putting F/I down. I just wish some people would see the larger picture. Sometimes there's more to a car's performance than a peak horsepower number...