If you increase the valve pressure (turn in the screw), you increase the valve's resistance to opening at lower vacuum levels, meaning part throttle or at idle but you also increase the occurrence of compressor surge, which is what a BOV is there to prevent in the first place.
U do know where is our airtrek turbo speed sensor located? My ODO speed meter aint working. The speed display on my turbo timer aint working as well. So i suspect there is no speed output from the...