You should change your name to "back to school". The EA888 (your GLI) and the EA888 evo4 (S3) are internally different engines, with reinforcements vs the non-Evo. The Evo has a different turbo from the non-evo. (Garrett (EVO 4) vs IHI for EVO Gen 3 and most non-Evo Gen 3/4) The Evo has a higher pressure fueling system (5076 PSI, compared to 2900 PSI on the non-EVO Gen 4) The Evo has changes to the camshaft and timing system overall, using a lighter camshaft. The Evo has changes to the intake system to allow the airflow to be more responsive to throttle input.