see i have a GT and i put headers on, the car still moves just fine from a start, actually i like it better now because daily driving is much smoother, and totally worth the pull in the high end...and this is commin from an n/a GP owner ha

anyway the loss of backpressure means less low end torque, the better flow means more high end torque. essentially your shift your powerband into the higher RPMS so the car wont fall on its face as much after 4500 RPMs