[BMW GENIUS]

Does anyone know if the firing order for the N55 is different than the firing order of the S55? I'm just trying to put together the pieces as to why they both sound completely different even though the displacement and engine layout is the same. Would the Bore/Stroke really change it that much? To me they sound as different as a cross-plane V8 (LSx engines) compared to a flat-plane V8 (Ferrari's V8 engines). Does anyone know or agree?

[configt]

I am more blown away by how quiet this N55 is in my M235i. I have had a lot of cars and this is by far the quietest/smoothest running engine I have ever experienced.

[hans007]

maybe they just turned teh volume up on the active sound... jk

i've sat in my friends f80 and though i havent driven a m235i , i've driven a 535 and an x3 with the n55. and yeah the n55 is so much quieter it does seem a little weird. honestly the n55 is one smooth buttery engine, and i'd say i like it more than the roughness of the s55.

[Bimmer86]

Originally Posted by hans007

maybe they just turned teh volume up on the active sound... jk

Not sure of the actual engine, but the ASD of the S55 is actually louder lol.

[BMW GENIUS]

Its not so much the volume as it is the pitch and tone. The N55 sounds a lot deeper and and barks and roars, as opposed to the S55's rasp and screams!

[335BOY]

probably the fake sound piped in.It does sound great

[BMW GENIUS]

My buddy just got the eisenmann black series exhaust for his F82 and it sounds like a boosted S54. Yet the N55 has the same displacement and (as far as I know) the firing order so what can make it sound so different OUTSIDE of the car? I'm not talking about the ASD inside the car.

[Cyberdemon]

I don't think the firing order is necessarily going to be any different, but you're talking about cars that from the time the exhaust leaves the combustion chambers have 2 completely different exhaust and turbocharger setups.

The F8x has two turbos each of which is collecting the exhaust pulses from 3 cylinders, vs the single turbo twin scroll exhaust manifold on an N55 which is pumping the 2 banks of pulses into one turbo. Beyond that you're piping the sound through a larger and more elaborate set of tubing that has different crossovers, diameters, etc.

Ultimately you're going to collect the pulses and amplify them differently as soon as they exit the engine block. Those sounds are going to cascade and cancel out differently and give you a much different sound.

If you've ever modified the exhaust on a turbo car you'll know you can get a lot of different results based on the catback, downpipe, up pipe, etc. Multiply that by a completely different turbo setup and I think you have your answer.