BMW Performance Modifications - BMW N51N52 - 3 Stage Intake Manifolds - Full Bolt-On Turbo Kitsbr br Verstarken notes that the BMW N52N51 engine is a naturally aspirated inline six-cylinder engine that was used in various BMW models from 2004 to 2015. br br One of the notable modifications to this engine is adding the three-stage intake manifold, which was designed to improve engine performance at low, medium, and high RPMs.br br The three-stage intake manifold and our Full Bolt-On Turbo Kit has been used in various BMW models, including the 1 Series, 3 Series, 5 Series, X1, and Z4. The N52 engine was used in the 128i, 328i, 528i, X3, X5, and Z4, while the N51 engine was used in the 128i, 328i, and X3.