i think 2 -3 psi is pretty noticeable as i did notice my car lost power and then i noticed it was boosting 10psi when before was 13. so you can feel a bit of diff. (my problem is probably a boost leak or for the fact that clutch is slipping.. dunno)
yea 2 psi is noticable but i beleave the threoy is it will drop boost but cause the boost is colder and more dense it produce same power. dont hold me to that lol. just wanted to check i was right in thinking it dropped a bit of pressure