I'm curious a bit as to what the over all sound of an engine is really a matter of it's exhaust and not the engine itself. Bit of an odd question, I know, but I think it can have a decent effect on one of my builds.

Now, I know different engines sound differently, but I'm curious as to how much of that is really just exhaust. A diesel sounds different than a gas engine because of how it works. An inline-6 sounds different than a V8 and so on. But what about a V8 vs another V8? If it's big-block vs small block the BB will be deeper and louder because it's simply bigger, but how about a 302 vs a 5.0? They're both the same displacement but my '67 Mustang's 302 sounds WAY different than my '89 Bronco with a 5.0. From start up to revs. I'm curious as to how much of that is the engine itself and how much is just the exhaust pipes and muffler behind it. Displacement isn't the only factor, I mean a Y-block sounds completely different than a 5.0, actually sounds a lot like an IDI diesel of all things.

I bring it up because a couple weeks ago at a car show a guy in a Ford GT floored it as he was leaving. Didn't peal out, didn't make a show, just made the engine loud and went fast. However I never in all of my life heard such ferocity from a car. It sounded like a T-Rex roaring. Wasn't obnoxious, wasn't overly loud, just sounded like a car that knew what it could do and could do a hell of a thing. But... the Shelby Mustang GT500 has the same engine in it, and the 5.4 Trition has been used in Ford's trucks as well. Now granite the GT and Shelby have different superchargers on them, and the truck version is tuned differently, but from my research the Shelby engine is basically the same except a slightly different cam (which if it was way different I could see, but it's considered marginally different) and rods. But the Shelby doesn't sound nearly as intense as the GT.

It got me thinking on it all, mainly of what I could do to get that sound from my car, lol. I know the GT has a very different exhaust, from the headers to the tail pipes, and I'm curious as to how much of it all is just that, and how much of it is engine choice.

I bring it up because, well, if I can get what i want from the right exhaust, engine choice isn't as strongly effected, if it's produced only from that exact set-up, well that changes things.


Any ideas?

 

Stephen,

I'm no exhaust guru by any means but I would think that two engines of identical build will have different sounds depending on several factors...

Cam... overlap and lift... headers vrs exh. manifolds... size of exhaust piping (exhaust and tail) larger ain't always better for the performance or the sound. Dual pipes feeding a single muffler or dual mufflers..... crossover pipe or not, type of mufflers...racing, turbo, stock, with or without cat converters... and in those areas... are the mufflers gutted..?? turnouts at side or rear also affect the sound.. add a megaphone to get an obnoxious sound

I agree...some of the mustangs sound almost like the gates broke and satan is coming, while other have a nice mild exhaust sound... The Chevy trucks get a unique sound by removing the cat conv and using a bypass pipe. It's a combination of several factors.

YMMV...

later
john

 

John is right. There are several factors involved. But the bottom line is, every engine will have its own, unique sound. You can have the exact same pipes and mufflers on a small chev, big chev, FE big block, Cleveland, sbf, Mopar big or small block, etc., and each will sound different. Someone familiar with them all could tell them apart blindfolded. And as John mentioned, when you start making cam and compression mods, that will change them all some, but again, if you know what they're supposed to sound like, you can pick them apart. Fords, imho, have always had a deeper, healthier sound than any chevrolet, which is why I figured they nicknamed chev engines after rodents.

 

All else being equal, one other factor that contributes to engine sound is compression. A higher compression engine will sound different from a lower compression engine.

 

I agree with the above (compression and cam - which equates to lift) that can effect the "sound" of an engine beyond the exhaust. I would add a third: power adders. Examples: turbos, superchargers, and even nitrous. All of these will give the engine a different sound too.

I have a very mild 454 that is going into my '73 Camaro. The exhaust I choose will make it sound nice, but it won't sound nearly as "snotty" as a high compression 454 with a big cam.

Phil

 

so , the engine is a big air pump, so you can kind of equate it to a pipe organ.
the size of the pipes, the length of the pipes can be tuned lower and higher, longer bigger diameter pipes contribute to lower frequencies. blowers etc push more air. Then you have the mechanical noises which can be amplified and carried along with everything else. higher rpms, roller rockers all that stuff. Music to my ears anyway.
Interesting question.

 

just a note (ha ha!!) I was playing with my 54 flatty (canadian ) and blew the muffler open ..loud ..expensive ..so I threw on a 30 buck cherry bomb ..expecting to hear a roar ..anda rumble ...damm thing is quiet ....just like before..so they are probably right ..so bigger header pipes ..and a big say 3 inch exhaust will make it rumble???

 

is you need be able to push enough air to fill the pipes. not sure my little holly, at 94 cfm would fill a three inch header.

 

so ...2 .1/2" should sound better ..L ol....

 

I sure hope so, I just ordered red's 2 1/2" long tube for 53 f100. I have a couple new 17" mellow tones to stick on the ends. I can hear this truck now with stock manifolds and 3ft glass packs, but just barely. Headers should be here in three weeks as he doesn't stock the coated ones. I'll put some audio clips together.
Me and this truck will make some beautiful music together I'm hoping
Bill

 

A thing to remember with exhaust size is larger isn't always better. If they're too large the exhaust cools and slows down, which backs up your engine and costs power. It's why I laugh whenever I see a Civic with a 4" exhaust like a diesel... course at that size the engine might not produce enough exhaust to fill the tube and back up when it gets cold, lol.


That's a good comparison BK. Makes a lot of sense. I know the GT has a different supercharger on it than the Shelby GT500. I know I seem a bit focused on that difference but I've heard a lot of great engines in my life, I have never heard a set up as beautiful as the GT was though, and I was waiting for a Lamborghini Countach to take off, lol. Too bad you can't get that across in a video or something.

 

Im not any kind of expert on the matter, but I do love the sound of any V8 with a fairly unrestricted dual exaust. When I drive all I want to hear is the rumble of the motor, the ride of the straight axel, and the way you can feel the road with manual steering and brakes along with the breeze provided by the cowel vent and ventilaters (wing windows) doing what they were desighned to do,(cool you by evaporating the swet as it forms on your skin) cruisin with arm on the door and waving back to all the nice folks giving me the high sighn as I go by. Thats what its all about for me. And any stock flatty or sixers all have my deep respect for still doing there job after all these years, they all sound perfect IMPO. Not that it makes any diference but Im throwing in my set up b4 I installed it, out the back, from my slightly modified 302. We all like different things for our trucks so this is just what I like, no what I love. Good luck finding the sound that makes you fall in love with it, Im sure you will.