What parts change the engine note?

Forza Horizon Forza Horizon 4 FH4 Discussion
1

Obviously changing the whole engine or the exhaust changes the engine sound but do any other upgrades change the sound?

What i want to know is how to boost the engine performance without changing the sound?

2

Conversion

  • Engine
  • Aspiration
    Engine
  • Camshaft
  • Rotors / Compression
  • Single Turbo
  • Twin Turbo
  • Positive-Displacement Supercharger
  • Centrifugal Supercharger
    That’s all.

Note

  • Essentially the engine sound (its tone) remains identical (unless you swap to a different engine option), with only the pitch changes.
  • The more power / less resistance the engine’s got, the higher pitch the engine sound tends to be of.
  • “Camshaft” and “Rotors / Compression” upgrades rise the limit of the pitch.
  • Different aspiration options add/remove the characteristic sound corresponding to the aspiration type. This sound alters according to the maximum permitted boost.
3

Too Simple.
The Camshaft increases RPM’s, which makes the sound higher pitched.

4

…by rising the limit of the RPM (Redline).

But which doesn’t pertain to the subject by much.

5

In real life, nearly every kind of upgrade changes the car notes in some way or the other. In Forza;

  • Exhaust upgrades may or may not change the sound
  • Cam updates with only make the revving sound higher (more high pitched)
  • Forced induction upgrades will introduce new sounds
  • Engine swaps will change the sound entirely

Think that’s about it.

6

The major problem of this sound system is the underestimation of exhaust’s influence.

While which basically defines the dominant part of a sound’s character…

It’s also the reason that why cars with similar engine configuration can have distinct sounds. (an I4 sounds like V12… possible)

Let’s take an apparent example:

The very pistol firing the same cartridge, with or without a suppressor.

Don’t think that they sound identical… (they do, in Forza Science though)

7

Yes, well, what can you do? They had this really neat feature in FM2 where sound character would change noticeably between different exhaust and cam upgrades.

8

None.

I remember adding ECU or ignition (don’t remember which) would change the pitch of the RB26 in FH3 but it was difficult to spot and probably an unintended effect.

It’s very possible to change sounds by layering a more aggressive sound over the quieter stock one, but this requires work, and all the focus seems to be on adding cars to prolong the game’s lifespan, so… not happening in FH4. We don’t even have FM7’s sound updates yet, all of which would be very welcome!

IRL you change the air filter and the sound changes. It’s that sensitive.

Personally I want really loud turbos, superchargers, etc. I add forced induction and I want to hear it. Instead, I have to pay attention to hear my huge turbos spooling. That’s something that could be improved.

I love driving cars with centrifugal supercharger upgrades like my 1993 Cobra R but all of my turbo cars have muted turbos and many cars with PDS have muted whines as well.

9

^^ Silly issues like these that make me want to stop playing the Forza games. What’s the point of collecting so many cars if they’re going to sound mostly the same or have wrong sounds altogether?

I think the sound character changing drastically with upgrades is something people have been requesting since FM3, because FM2 was their last good game with sound changes to cars’ character after applying upgrades.