True, in gt3 the noise is less noticable. The purpose of a blow-off valve is to keep the turbo spun up between gears so that it doesnt take forever for it to spin up again. The GT-one has a VERY distinct and clear sound, but the fact is, with lower hp cars and ones with smaller turbos or ones without the frequent shifting racing transmission, you wont notice the sound nearly as much as Gt2. It is more realistic, but it doesnt sound as cool. I also agree w/ the straight pipe thing. If i got a cobra 427 w straight pipes, i wanna hear it! it sounds cool, but it isnt loud enough! That baby should ROAR!