[AlphaKilo]

Originally Posted by amit_mechengg

Not exactly. Its combination of many factors. The fluid dynamics of exhaust gases generated from the exhaust valves, their timing, flow rate, velocity and similar many factors.

A honda city cannot sound like AMG if you implant a AMG exhaust onto honda city.

Would be greatly helpful, if you manage to elaborate your points. My bare basic idea was so because, even a roaring engine can be muffled and made to sound like a pig, by tuning or playing around with the exhaust system and mostly, the sound is damped/augumented in the exhaust system. But as you said, there is lot more to it than just exhausts which cause the noise! I would say, exhaust helps to release the sound created in the engine into the atmosphere as much as it exhausts the expelled gases. I love to learn, so correct me if I am wrong.

[Latheesh]

I love our TATA 407 :-) that is very unique!

Agree with above comments, its a result of combination of entire system design

[Guna]

BTW the boxer engine in the Forester makes a very different sound (known as Boxer growl) which is attributed to the unequal headers.

[Sutripta]

I would think that the major categories would be
Exhaust
Induction roar
Mechanical noise.

I think you are concentrating on the exhaust. For that, the most important is the firing order of the cylinders, and the exhaust system plumbing.

It is because of the firing order that different engine families have different characteristic sound signatures. But not always. The traditional American V8 sounds very different from the V8s of European exoticars. (Different cranks configurations). The inline twin can have different firing arrangements, sounding very different.

Next are the various exhaust systems. Nowadays however, emission legislation means that variety in exhaust systems is being stifled. The turbo, if used, dampens sound.

Sound as a signature is a very powerful emotive issue. (Harley, I believe was trying to copyright its sound). Mazda spent a huge amount of effort to make the Miata sound just right. And look at all our Bulleteers bemoaning the loss of the old bullet thump in the new engines.

Regards
Sutripta

[suhaas307]

^^ I'd like to supplement Sutripa's post.

Toyota/Lexus sought help from Yamaha Acoustics for the purpose of tuning the exhaust-sound in their LF-A supercar.

AMG tunes exhaust in their cars to produce that deep rumble and that bellow you hear when one steps on the gas.

Porsche has given the exhaust-note quite a lot of priority, in the new 991 type 911, so that it spits and crackles in the overrun.

[skandyhere]

Originally Posted by vina

What is on-topic raises the question of what you mean by "slow sounding" - do you mean the pitch (also called frequency) of the clatter? That is low not because of bore/stroke, but because the engine is low revving in the first place.

This is probably on the fine line between relevance and being , but well, the engine is low revving in the first place because the stroke is long. Obviously the stroke, among myriad other things, does influence how the engine sounds, which in turn influences how the car sounds.