Originally Posted by BmwECY
that's a bunch of crap, coming from a n55 owner. let's consider some facts:
-1//m uses n54
-335iS uses n54
the n55 is under-performing with the same mods/tuning as the n54. so, with downpipe, intercooler, and 15+ psi, you'll be nowhere near a n54 with the same hardware/tuning. the n55 is a crap motor that's about to be rendered obsolete when the 2013-14 340i and 440i come out.
Your post is crap.
Oh and how about this. N54 sounds like crap. N55 has an exhaust note of the gods