How much of an engines sound is due to exhaust?

[paulpsz008]

So I'm working on a project car at the moment and just wondering which way to go engine wise and started thinking.

How much of an engines sound is due to exhaust design, and how much is purely from the engine?
Obviously my project will end up with a custom/modified exhaust system on it.

[stevesingo]

The intake system can generate almost as much noise as an exhaust.

See here...

http://www.youtube.com/watch?gl=IE&hl=en-GB&am...

Steve

[Jerkins]

stevesingo said:

The intake system can generate almost as much noise as an exhaust.

Certainly in the case of my car - I fitted bike carbs to my toy's 1660cc x-flow engine, and the intake noise is FAR noisier than the exhaust!

I really must do something about it, probably by fitting an air box (but I don't really want to... )

[stevieturbo]

What do you mean by sound ?

Obviously the engine moving air creates the sound. But what you actually hear is largely determined by exhaust design, and the volume of air the engine is shifting.

[mwstewart]

Cam specification also plays a big part in distribution of sound.

[Daston]

As well as the fire order of the Cylinders.

[Nick3point2]

mwstewart said:

Cam specification also plays a big part in distribution of sound.

Cam timing in my opinion is the best way to improve the sound of an engine, instead of just making it louder!

[pblake55]

totally agreed,

Nick3point2 said:

Cam timing in my opinion is the best way to improve the sound of an engine, instead of just making it louder!

[macdeb]

Daston said:

As well as the fire order of the Cylinders.

and how many.