Glad to hear its common if not normal. Right now my recirc is about 1.5'. I wanna make sure we are on the same page just gauging my issue. When you let off under load it pops a few times not LOUD BANG but pop, pop, pop kinda like an exhaust leak but no real pattern.

 

I would assume this is what you did, but be sure the recirculation goes back before the turbo, also a popping sound when you let off the throttle, if it pops more then once can be a lean condition be careful with this as it can really spike your EGT's. That being said if you do have a exhaust leak it will pull in air and can burn additional oxygen in the exhaust track again making a popping noise. Before getting it tuned better ( which is the most likely culprit) make sure everything is tight and there are no leaks anywhere.