I don't believe there was a turbo 240z made Kris, the 280zx (L28ET) responds roughly the same with boost (on it's 60trim t3) 15psi is about 250whp on both motors.

The SR is clearly a more technologicly advanced motor, but the torque compared to an L28 is nothing. Although with that light of a car, who needs 300ft/lbs of torque @ 15psi?