This video is fantastic for showing you a prime example of screamer pipe noise!
http://videos.streetfire.net/hottest...969A262AD1.htm
Wait till about 2mins20 or so onwards, basically all the in car stuff.
The car is well laggy so there is a long time when not on full boost, then you can tell exactly when full boost hits, often changes down a gear to get it on boost.
Mega sounding car once the screamer opens