Hello everyone, kinda new here, but learning as i go along.

1. I got a buddy with a 18g on his dsm. Now he has a internal wastegate i belive, and when he shifts or lets his bov surge, his wastegate from what ive been told and heard makes a chuckling/laughing sound, its a repetative surge. can anyone explain this and maybe give a reason on how to duplicate it?
if you go on kazaa and download a video of the twinturbo viper, it produces the same sound.

2. If you have 3inch exhaust piping but on the stock muffler, will this produce any bad effects? or bottleneck type of effects?

 

anyone,?