This includes lining up pipes behind BMW’s N52 inline-six, and its great-sounding cat-back option (Heads-up, at the time of this writing, there’s a sale on it for 128i owners).

BMW's N51 and N52 engines are practically identical, ... are offset by its superior intake manifold and factory tuning. The changes don't affect the N51's reliability either, ...

But the aftermarket is usually always better for this type of part, and in my case, I decided to throw on Turner Motorsport’s N52 intake for the E8X and E9X BMW chassis.

BMW's N52 engine is popular among automobile enthusiasts, but it's not all rosy. Some years are better than others, according to those same gearheads.