Great addition for a stock or lightly modded engine. The device bolts on and restricts airflow to the waste gate below full boost allowing quicker spool and MUCH more low end torque. Factory overboost protection remains in place. Can be used with Stage II software, factory banjo bolt must be re-installed for use.
Full boost comes at 3500 RPM as opposed to 5500 RPM and the torque curve is much flatter. Excellent for posting lower times on the track.
Had on my 87 944 Turbo for about 150 miles, decided to pursue other avenues of modification which will require me to remove it.
Works as advertised, barely used, original paperwork/installation instructions.