Okay, I guess I'll pitch in my 2, 3, or maybe hundreds of cents.
I've been playing GT2 quite a lot recently, so.....
For some reason, sticking race exhaust on some cars DRASTICALLY changes its exhaust note, sometimes to something that the engine is NOT.
eg. Toyota Supra 2.5 TT-R, Subaru Alcyone SVX, and the Venturi Atlantique 300.
Race exhaust on any of these cars make them sound like FOURS rather than SIXES.
I think that's all I can say for now. Back to GT5 sound discussion.
I remember that distinctly (the Twin Turbo R was my first car
)
I think it's because a race exhaust is typically equal length, which tends to remove any semblance of the engine's geometry, and makes it sound like it's revving far higher - a race-tuned 6 should howl and scream like half a V12, and is not too dissimilar to a race-tuned four at 6/4 times the RPM or, indeed, a flat-plane V8 at 6/8 times the RPM.
Now, what that means is, PD clearly selected a stock (that is, from a library, not necessarily "standard", unmodified) sample set to try to get that fizzy howly stuff going on, and just ended up using what sounds like a NA rally car, or touring car etc (usually 4 cyl.).
Of course, all of this only applies to the exhaust; the intake still has its own distinct sound. Race machines typically have their own runners (with throttle bodies), sometimes feeding into a common plenum, sometimes "open", which often means the geometry of the engine (cylinder pitch, bank separation, any difference in runner + port length - think VW VR / "W" engine) is evident in the intake sound. Back in GT2, though, there were no separate intake / exhaust sounds.
Even now, we're still waiting for proper intake sounds.
V6 equal length exhaust
Straight six equal length exhaust
V8 intake (
exhaust)
Straight 4 intake
Straight 6s (from
1:35 demonstrates the requirement for separate intake / exhaust sounds
)
Now, some engines have built-in differences in the port length:
Kawasaki Z1300 (straight-six, slight difference due to ports clearing frame) ->
with race pipes which compensate for the difference. (
pic)
VW VR6 (cylinders are staggered, so every other port is considerably longer - gives that lumpy quality)
Finally, a V12
screamer...
I could go on for days
One thing to notice in all of these videos, is ambient noise, reflections / reverb, distortion due to microphone and its housing (esp. in video-cameras) and lack of focus of one particular sound (e.g., intake sounds are accompanied by the sound of the drivetrain and ancillaries.)
It's just something you have to deal with, and is why a multitude of recordings in different places, in different situations are required.
