Why does turbo engine produce less engine noise than naturally aspirated engine?

[mofbb]

Sorry for the noob question. Tried search google and the answer said turbo engine are usually smaller engine. However, many of BMW cars are using 4.4L turbo engine but why is it still makes less noise than the M3 naturally aspirated 4.0 v8 engine ? Thanks !

[tibra1]

The turbos actually "muffle" exhaust sounds to an extent..because the exhaust are being redirected to drive a turbine in the turbos..I was shocked at how "muted" my 335 sounded even with a full catless setup

[Mahzari]

A turbo works by using some of the exhaust gases to spin the physical turbo compressor. It is a very efficient muffler of engine sound.

[mofbb]

Thanks for the quick responds ! I really appreciate that !

[djt511]

Thats why most complain of the lacking grunt of the GTR, and possibly the future M3...

[IFX]

I don't care why. All I know is, the N/A sounds badass. The only turbo motor i've heard, that I like and is completely stock is the Porsche Turbo.

[Krozi]

The turbo absorbs a lot of exhaust pressure by spooling the turbine, thereby muffling sound.

[socalm3lover]

Also, the E9X NA engine is far more "on the edge" to make the horsepower they want. With turbos, you will have a mild engine and with the boost, make a lot of power (and a lot more with a simple chip).

Not sure what I will do, but I if I get the new one, I will definitely miss the radical mechanical cacophony of this engine.

John

[btgM3]

one of the few gripes with my 997 TT was the lack of an exhaust note...always regretted not taking the gt3 that was on the lot that day

[S65frk]

So are we talking about engine noise or exhaust noise two different things? Because it makes sense why the exhaust is quieter but what about the engine?

[rjd598]

Originally Posted by IFX

I don't care why. All I know is, the N/A sounds badass. The only turbo motor i've heard, that I like and is completely stock is the Porsche Turbo.

[GeeRam]

Originally Posted by m3alabama

Turbo's don't rev that high but if they did (and a few do) the intake sound is just as loud or even louder.

Especially with ALS

[TK-421]

My friend's big single 1JZ in his S13 safely revs to 10K if he takes the rev limiter off. With an open downpipe it's loud as shit (especially the "pop" when a fireball shoots out) but is noticeably quieter than, say, a Honda K20 revving just as high with straight pipes. Basically +1 to most of what's been said already. And idk why the F10 M5 needs that bullshit with its speakers replicating engine noise - I've driven a stock E63 with the TTV8 and it's pretty loud.

[MediaArtist]

BMW needs a premium option to add a speaker to your exhaust to really show off that beautiful computerized V8 engine note.

[Sniz]

Originally Posted by IFX

I don't care why. All I know is, the N/A sounds badass. The only turbo motor i've heard, that I like and is completely stock is the Porsche Turbo.

huh, they dont sound good at all

Originally Posted by btgM3

one of the few gripes with my 997 TT was the lack of an exhaust note...always regretted not taking the gt3 that was on the lot that day

exactly

now modified they can sound pretty wicked, but stock I think they sound really not pleasing.

how they drive is a different story

[Fugly M3]

doesn't the M3 also have 1500 rpms on the bmw turbo engines? is it not also designed to be aggressive-sounding? I get that turbos are generally quieter, but the M3 is generally designed to be louder, no?

[Sniz]

Originally Posted by E46M54325Ci

doesn't the M3 also have 1500 rpms on the bmw turbo engines? is it not also designed to be aggressive-sounding? I get that turbos are generally quieter, but the M3 is generally designed to be louder, no?

rpm does not dictate volume. If that was the case my dremel would blow my ears out.