Exhaust sound

[bulldog]

I am new to V8 performance exhausts. I have not been very excited about the exhaust sounds. The closest thing that I like so far is the Corsa. What I would like to get is a sound that is close to the sound of a mustang. The Camaro sound is just raw and loud. I dont know how to describe the mustang sound other than calling it a gurgling sound (not the drone sound).

Here is best example of the sound that I could find



So what is it about the camaro sound as compared to the mustang? Obviously there is a completely different engine, different displacement, but I dont know what to call it (harmony or melody) of the mustang sound, is there any way to get more of a harmony/melody sound that is more like the mustang, instead of the raw sound that I am hearing from the Camaro?

[Paperer]

That's what I have always heard from guys at muffler shops. They tell me they have people come in and they want their car to sound like another, and they tell them "Well, go buy that car".

I only hear a raw sound on a Camaro when a cat back system is installed. The stock exhaust sounds more like a Mustang to me.

[THE EVIL TW1N]

Originally Posted by bulldog

I am new to V8 performance exhausts. I have not been very excited about the exhaust sounds. The closest thing that I like so far is the Corsa. What I would like to get is a sound that is close to the sound of a mustang. The Camaro sound is just raw and loud. I dont know how to describe the mustang sound other than calling it a gurgling sound (not the drone sound).

Here is best example of the sound that I could find


So what is it about the camaro sound as compared to the mustang? Obviously there is a completely different engine, different displacement, but I dont know what to call it (harmony or melody) of the mustang sound, is there any way to get more of a harmony/melody sound that is more like the mustang, instead of the raw sound that I am hearing from the Camaro?

some of it probably has to do with the firing order.

[GoldBowtie]

There are lots of Mustangs around here and I would never want my Camaro to sound anything like them. IMHO Mustangs sound like an artificial, exagerated sound. Camaros and Corvettes sound genuine, like the engine really produces that sound (even if it derives from the aftermarket muffler). You can tell a Mustang without looking since it sounds like a microphone was added to a small engine of some kind.

[Kilo-9]

Originally Posted by THE EVIL TW1N

some of it probably has to do with the firing order.

This is what I've been told, too.

[Doc]

Believe it or not an exhaust system is not unlike a pipe organ; moving air through pipes. An organ's pipes are tuned through diameter and length to get the desired pitch. The amount of air moved through it determines the softness or strength of the sound; small amount of air = wispy; strong flow of air = bigger tone with more body to it.

The exhaust tone of a car starts in the cylinder; it's diameter and length of the chamber. The size and shape of the combustion chamber plays a part. The valve size and shape plays a part as it controls the release of the air into the pipes. The diameter, length and thickness of the exhaust pipe shapes the sound a lot; bends in it dampen harmonics. Look at a pipe organ; straight pipes to get the maximum pure sound yet they still use dampeners to control harmonics. Exhaust pipes are shaped and bent according to what's necessary to feed them into the collector and route them to the back, which does affect sound.

Firing order affects sound as each pipe is slightly different from the others and is "played" by the explosion of air being pushed through it. The cat and muffler obviously affect the sound by what they absorb and dampen. By the time the air gets out the back it's been bent, twisted, turned, dampened, absorbed and slammed around anywhere from a few hundred to a few thousand times a second; 8 cylinders are singing through those 2 pipes. You've probably noticed how different rpms produce a different sound from the same setup; it might go from raspy to sweet to raspy again all in one run through the rpms. The air pulses created by revolutions per minute create frequencies all their own.

It works like a piano; certain frequencies work in harmony, others clash and produce dissonance. Pluck a guitar or piano string and watch it; for a few seconds you'll see the harmonic wave pulses along the string where the string appears blurry and wide and narrows to the actual string width. The narrowest part is the harmonic node which has the most balance and the least resistance. Air moving in pipes works exactly the same way. Believe it or not the very best, most efficient exhaust system would be one designed to play like a musical instrument, with the harmonic nodes hitting perfectly at the beginning and ending of the CAT and Muffler, and finally the end of the exhaust pipe. It would flow the best, sound the best, and probably be a total PITA to design and test. But man what a sweet sounding system that would be.

If you took an 8 ft piece of 3" exhaust pipe and tapped it with a hammer, it would ring like a tubular orchestra bell. Those are the harmonics you have to control. The size and length of the pipe, the thickness of the tube wall and metal it's made out of determine the pitch and sound quality. Actually, now that I'm thinking about it, tubular bell designers would probably be very helpful in designing a header/exhaust system.

For our purposes to find the "best sounding" setup you'd have to test every header with every cat and muffler combination and pipe diameter to see which sounds the best. Not an easy or practical task unless you're a performance mag with the resources to run such a comparison. Although if one were to actually do this, I suspect the combination that sounds the best would also be the one that performs the best.

[Doc]

Oh and as for the sound clip posted, Mustangs have a higher pitched sound; more treble and midrange frequencies. The Camaro has a deeper tone with more bass frequencies. Pipe diameter plays a critical part in complimenting those freqs.

[FiLTHy PHiL SS/RS]

Try hooking up a rusty trumbone to your exhaust and tune that sucker in...

:party0048:

[MTron]

Originally Posted by Doc

Oh and as for the sound clip posted, Mustangs have a higher pitched sound; more treble and midrange frequencies. The Camaro has a deeper tone with more bass frequencies. Pipe diameter plays a critical part in complimenting those freqs.

Truly an epic post and description as to the sounds involved in exhaust systems!...Good Job!!

Coming from the IT world, i would like to remind people who watch all these vid's on the Camaro's exhaust to note that 99% of consumer electronics are extremely sub-par on their ability to record lower frequencies with any reasonable clarity and accuracy. For example, if you look at even mid-range HD camcorders they have relativly small mic's, but go look at a standard definition TV camera (used by reporters and such) or a very high end standard def camcorder and the mic will be much larger.

So you may have a nice camcorder for vid's, but your sound reproduction is not where you think it is

All this adds up to the fact that most vids posted of the exhaust will lack a great deal of the bass reproduction.

Oddly enough, if you want to get a better sound clip, move the camera FURTHER away from the exhaust, which allows the bass frequencies to propagate more which allows for a more even recording level (as the higher frequencies dissipate faster then the lower frequencies) allowing the volume to be boosted a bit to compensate

[brandotron]

Originally Posted by Kilo-9

This is what I've been told, too.

Me three. I always thought the mustang guys had the cooler exhaust note, while we're stuck with all the horsepower.

[Doc]

Originally Posted by brandotron

Me three. I always thought the mustang guys had the cooler exhaust note, while we're stuck with all the horsepower.

Of course if you have a Camaro you don't often get to hear the mustang exhaust notes because they're always behind you.

[Doc]

Originally Posted by MTron

Truly an epic post and description as to the sounds involved in exhaust systems!...Good Job!!

Coming from the IT world, i would like to remind people who watch all these vid's on the Camaro's exhaust to note that 99% of consumer electronics are extremely sub-par on their ability to record lower frequencies with any reasonable clarity and accuracy. For example, if you look at even mid-range HD camcorders they have relativly small mic's, but go look at a standard definition TV camera (used by reporters and such) or a very high end standard def camcorder and the mic will be much larger.

So you may have a nice camcorder for vid's, but your sound reproduction is not where you think it is

All this adds up to the fact that most vids posted of the exhaust will lack a great deal of the bass reproduction.

Oddly enough, if you want to get a better sound clip, move the camera FURTHER away from the exhaust, which allows the bass frequencies to propagate more which allows for a more even recording level (as the higher frequencies dissipate faster then the lower frequencies) allowing the volume to be boosted a bit to compensate

Thank you.

Very true and while bass frequencies are omnidirectional, mid-range and highs are just the opposite; very directional. Mic position can have a huge effect on the perceived sound tone.

Mtron... Mellotron? Fantastic instrument; fantastically expensive in its day and a fantastic PITA maintenance-wise but oh what a sound! Do you use or know of the Mtron emulator by M-Audio? Killer digital reproduction of the Mellotron without the maintenance hassles.

[MTron]

Originally Posted by Doc

Thank you.

Very true and while bass frequencies are omnidirectional, mid-range and highs are just the opposite; very directional. Mic position can have a huge effect on the perceived sound tone.

Mtron... Mellotron? Fantastic instrument; fantastically expensive in its day and a fantastic PITA maintenance-wise but oh what a sound! Do you use or know of the Mtron emulator by M-Audio? Killer digital reproduction of the Mellotron without the maintenance hassles.

Heh, yea it is a great instrument, and i know of, but never used the emulator, but i am very familiar with MAudio

As for my name, its actually just the first letter of my first name, and the first 4 of my last. All through school everyone called me Tron, cuz my last name was too long to often say, and Matthew was ridiculously common.

In later years it has been adapted by friends to stand for MegaTron in reference to my size (6'5 , 270 lbs) or Tronbulance/AmbuTron in reference to a university party which got a little....(lol...little)...out of hand

[uke]

Everyone else covered it pretty well, but yeah, you're not going to get your Camaro to sound like a Mustang without transplanting a Mustang engine into your Camaro (in which case you should be smacked...hard). The firing order, harmonics, etc can't be duplicated without completely changing the engine.

I suggest looking up soundclips of different Camaro exhaust setups (or GTO/Corvette clips, since they're VERY similar) and find out what you like.

I have a Magnaflow setup with longtubes, h-pipe, and bigger camshaft in my LS2 GTO. It has a little bit of a hollow ring to it in the 2-3K rpm range, nice rumble at idle, and wails like a banshee at WOT. Works for me

If you like a bit more raw, roaring sound, I might suggest either Spintech mufflers or SLP Loudmouth. The Corsa's were a bit too high pitched to me, but that's just my preference.