Some major differences from the FSI to TSI include:
-- chain timing vs belt as seen in the FSI
-- different fuel/engine management system
-- components in the intake system (as defined above)
-- oil filter and oil dipstick relocated
-- improved PCV system (proved to be problematic in the FSI)
-- compression ratio lowered to 9.6:1
-- more balanced cam shafts in the center of the block on both sides
-- down pipe
-- better emissions (by U.S. standards and regulation)
-- more 02 sensors on exhaust system