#1 - No. If the turbo says "Up to 550hp" or what not, it's just a rough guess of where the turbo will stop making more power. However, there are so many other factors inolved.ok so I got 2 questions.
#1 - if a turbo says "horsepower: 150-250" that means the horsepower it will increase above your vehicles current base hp right?
#2 - as well im sure the a/r size on the cold side of the turbo is important in some aspect, the a/r size on the hot side determines your bottom-end torque or top-end hp rating right? (ie: larger a/r means higher top-end hp, where lower a/r means better bottom-end torque but less hp on the upper rpms
#2 - for the turbine (hot side) a/r, the higher the number the higher the top end but longer spool up. Lower the number means it'll spool up quicker.