Turbos make big power wasy, A trans needs to be pretty stout!
On my current lowest possible boost setting at 10 psi, my 3,800lb car still went 130 mph through the traps at the 1/4 mile dragstrip! That has gotta be about 700 hp at the crank. On "low" boost.
What are you going to do with the car? drag? Road race? show?