Quote:
Originally Posted by quenotte
BMW also had that kind of "hose to firewall" on previous models like Z4 3.0si.
A closer example: M235i vs M2 OG airbox!
M235i and M2 OG share nearly the same engine (only different spark plugs, pistons, oil pump, diverter valve).
M2 OG has, on top of regular full pipe from behind kidney grilles, an additional red opening in engine bay:
This additional opening adds some engine induction noise and you will clearly hear more turbo noise.
I test this 335i MPPK/M2 OG airbox when I had my M235i.
So, yes, not having full ducted pipe may be to provide more engine induction noise  |
Does that opening make a such a difference? I think the ASM or Exhaust noise will overlap the duct noise.
Hose to the firewall is this one, you can really hear the engine breath, one yo change to an aftermarket exhaust, is inaudible
