That ain't flutter, that's dose. You need a dose pipe. You don't have an airbox so you're going to have to shove a 90° metal pipe on the front of the turbo and sit it nice and tight against the back of the power steering res and put a small pod filter on it, and you'll need to block off the BOV off too... Do a search for dose pipe, there's sh*t everywhere about it. This is my old car with a dose pipe when I first got it with stock a stock tune: