I have a 2015 STI. When I'm taking off and the RPMs are going between 3k and 4k, I hear what sounds like a vibrating metal coming from the engine. This a normal turbo sound? I assume so but I wanted to make sure. Also if I am going about 4k RPMs and I press the gas hard and let off I hear a poof of sound. I assume that's the blowoff valve?
P.S. I'll record some of this sound on the drive home and post it later.