Hi Italian?
First you need to do a compression or leak down test. Leak down would be better compression is not bad either. Instruction are on the net just search how to. Next someone very wise once said " with great power, comes great responsibility. While the NA and TT look the same they are not the same car. The TT has a slew of other parts that help it become the legend it is. LSD, 6spd, oil squirters, bigger radiator, bigger brakes, etc. so while yes you could technically make great power going NA-T don't forget the additional power causes things to break and get hot. So I recommend making sure your car is ready mechanically prior to going turbo. Rant over