Exhaust sound

Breaking news, useful data or technical highlights or vehicles that are not meant to race. You can post commercial vehicle news or developments here.
Please post topics on racing variants in "other racing categories".
Engineer
0
Joined: 02 Aug 2009, 13:02

Exhaust sound

Post

Hi guys

I have a question about Porsche Carrera GT exhaust sound .
I know it's not an F1 question,but from previously asked questions,I've receved the most info right from this site .
So...Why/how does the Carrera GT exhaust system creates its specific sound.
Where is the key,how does it work?
I know ste sound is influenced by the intake manifold design or different tipes of filters (racing filters)and the exhaust system design.And that's it.This is where my knowlege stops.
So,if anyone knowsor has any useful info,I would be really gratefull for it.

Tnx for your answers,and I'm looking forward to read them

by by

Giblet
5
Joined: 19 Mar 2007, 01:47
Location: Canada

Re: Exhaust sound

Post

Fair question, but it has been posted in the wrong category. I will move it to 'Automotive news and technology subforum'.

Without going into too many details, as they are far too reaching, I will say that few people take into account much of what they are hearing is the intake sound. You are actually hearing the engine from 'both ends' when outside. An F1 driver mostly hears the intake when at speed, well unless you drive for Renault and the exhaust outlets are at the front of the car.
Before I do anything I ask myself “Would an idiot do that?” And if the answer is yes, I do not do that thing. - Dwight Schrute

User avatar
Pandamasque
17
Joined: 09 Nov 2009, 17:28
Location: Kyiv, Ukraine
Contact:

Re: Exhaust sound

Post

What do you find so special about the Porsche Carrera GT sound?
Don't get me wrong, it sounds wonderful, but from what I've heard in my close encounters with this car it sounds not much different from other high revving naturally aspirated V10 engines (not that there are many that rev as high :) ).

Caito
13
Joined: 16 Jun 2009, 05:30
Location: Switzerland

Re: Exhaust sound

Post

For reference:
[youtube]http://www.youtube.com/watch?v=fdePhx9HVjo[/youtube]



It sounds great, but I don't think it's a "different" sound.
Come back 747, we miss you!!

hecti
13
Joined: 30 Mar 2009, 08:34
Location: Montreal, QC

Re: Exhaust sound

Post

the noise from an engine is defined mainly by the number of cylinders it has. back in the day when you were allowed to have any type of engine configuration in f1, you could easily point out what type of engine a car had just by the noise it made. v12s shout, v10s are flat(like in the carrera gt and gallardo) and v8s "rumble". some things that affect the noise are induction and exhaust design, whether its carbs, itb's, or single tb, turbo or supercharged. The exhaust obviously has to muffle that noise for the car to be street legal, thats why the carrera gt has a muffled sound to it(compared to a v10 f1 car). engine displacement can also affect the noise (pitch) as well.

Caito
13
Joined: 16 Jun 2009, 05:30
Location: Switzerland

Re: Exhaust sound

Post

We could say not only number of cylinders, but the interval at which they fire is very important too.

You can have odd fire, even fire, and they make very different sounds.

With an exhaust you can equalize it, but the DNA of the sound resides mainly in the interval and amount of cylinders.
Come back 747, we miss you!!

User avatar
Holm86
243
Joined: 10 Feb 2010, 03:37
Location: Copenhagen, Denmark

Re: Exhaust sound

Post

I think the Carrera GT has a very specific sound.

Many of the other V10 supercars sounds more alike eachother but the Carrera has a unique sound in my ears. Very smooth yet very aggresive.

Its the only car i think sounds better with the stock exhaust than with an aftermarked one.

hecti
13
Joined: 30 Mar 2009, 08:34
Location: Montreal, QC

Re: Exhaust sound

Post

Holm86 wrote:I think the Carrera GT has a very specific sound.

Many of the other V10 supercars sounds more alike eachother but the Carrera has a unique sound in my ears. Very smooth yet very aggresive.

Its the only car i think sounds better with the stock exhaust than with an aftermarked one.
I know what you mean, the first time i heard one i described it as a "coughing" noise. It for sure has a tuned exhaust and was designed to sound like it is, but it still sounds like a v10, flat and wailing.

Formula None
1
Joined: 17 Nov 2010, 05:23

Re: Exhaust sound

Post

The Nissan VQ35 engine from the mid 00s was very melodic for some reason. It always surprised me to hear a 350z, infiniti g35, fx35 suv, etc., from that era due to it's distinct warbling sound. Anyone else notice that? I'm curious how they created it.

Jersey Tom
166
Joined: 29 May 2006, 20:49
Location: Huntersville, NC

Re: Exhaust sound

Post

Formula None wrote:The Nissan VQ35 engine from the mid 00s was very melodic for some reason. It always surprised me to hear a 350z, infiniti g35, fx35 suv, etc., from that era due to it's distinct warbling sound. Anyone else notice that? I'm curious how they created it.
Yup. And I get to hear it every time I get in my car :)
Grip is a four letter word. All opinions are my own and not those of current or previous employers.

alelanza
7
Joined: 16 Jun 2008, 05:05
Location: San José, Costa Rica
Contact:

Re: Exhaust sound

Post

hecti wrote: and v8s "rumble".
I'd say that's only true of crossplane V8s, hi revving flatplane ones such as the ones used in f1 sound more like 2 inline 4s stuck together
Alejandro L.

User avatar
Pandamasque
17
Joined: 09 Nov 2009, 17:28
Location: Kyiv, Ukraine
Contact:

Re: Exhaust sound

Post

alelanza wrote:
hecti wrote: and v8s "rumble".
I'd say that's only true of crossplane V8s, hi revving flatplane ones such as the ones used in f1 sound more like 2 inline 4s stuck together
Good point. Let me illustrate. This is Aston Martin V8 Vantage GT2.
Here's the sound with the earlier crossplane crank engine:
[youtube]http://www.youtube.com/watch?v=0ofFf8tv80k[/youtube]
This is the 'same' 4.5l V8 engine but with flatplane crank for 2011:
(jump to 2:00)
[youtube]http://www.youtube.com/watch?v=nyR0EC_ZaxU[/youtube]
hecti wrote:... engine displacement can also affect the noise (pitch) as well.
I don't think that is correct, not for pitch anyway. I can't find it right now but I had a formula to calculate the rpm based on the pitch and the number of cylinders regardless of the displacement.
Holm86 wrote:I think the Carrera GT has a very specific sound.

Many of the other V10 supercars sounds more alike eachother but the Carrera has a unique sound in my ears. Very smooth yet very aggresive.
The Lexus LFA sounds similar. That's the only thing I like about that car :?
[youtube]http://www.youtube.com/watch?v=u2UHaSRGBaY[/youtube]

hecti
13
Joined: 30 Mar 2009, 08:34
Location: Montreal, QC

Re: Exhaust sound

Post

i love v10s

RH1300S
1
Joined: 06 Jun 2005, 15:29

Re: Exhaust sound

Post

Perhaps someone can confirm this......

It seems entirely logical to think that cam design and compression ratio also has an effect on exhaust note. I can imagine a valve being opened aggresively will have sound different to one being opened gently. Or perhaps a 'cammy' engine just produces a more violent bang.

We all know the difference between a car with a loud pipe but no tuning to one that is making power and a sensational sound.

Caito
13
Joined: 16 Jun 2009, 05:30
Location: Switzerland

Re: Exhaust sound

Post

At least in idle you can certainly hear a difference between cams.

With a lot of overlap you can hear the engine go:

pa pam pa pam pa pam

rather tan

pa pam pa pam

you get it.. right? jaja.
Come back 747, we miss you!!