Can you put your stock turbo back on or was that the core for the smoker you got in there now? That's where my money is, usually if you have a bad ring/piston it will smoke on decel even without a huge pull beforehand and it won't have near perfect compression. I've seen many of my shitty turbo cars puff smoke between shifts on some 20g that came off of another POS DSM but otherwise didn't smoke at all. Got another 20g with a lot less POS and it never puffed smoke again.