determining factor of exhaust/muffler sound?
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From: near chicago illinois
Car: have a 92 camaro rs...in pieces
Engine: none now...probably 383 stroker
Transmission: none yet
Axle/Gears: none
determining factor of exhaust/muffler sound?
I was curious what determines the exhaust sound? Every vid ive seen of one brand of muffler/exhaust sounds different on every car.... Here are a few vids of what sound id like to get when i get around to the exhaust..... the first you could here right off the bat what i mean as soon as he accelerates... http://www.youtube.com/watch?v=DS0D7LhoVjs. This second one starts at 1:20 into the vid.... http://www.youtube.com/watch?v=PSJ-AwBYBJI .. Heres the last... This last one just sounds sick. Just has a little more treble sound to it, which i dont want ... http://www.youtube.com/watch?v=H4c21_HO0PE. The only way that i could describe it is that it has somewhat of a demonic sound to it... I know a lot of mufflers sound good at idle but as soon as you punch the gas is just sounds like crap... Id like the mufflers/exhaust to maintain the sound at idle, through higher RPM's...
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From: near chicago illinois
Car: have a 92 camaro rs...in pieces
Engine: none now...probably 383 stroker
Transmission: none yet
Axle/Gears: none
Re: determining factor of exhaust/muffler sound?
Anyone know the answer to my question??? Im trying to find out what internals in the engine, as well as power adders contribute or alter exhaust sound. I dont get why companies put up vids of their exhaust sound when it wont even sound like that on other cars, unless its another one of the same exact car (N that might not even be the case)... If 2 guys both have the same exact exhaust on their cars they wont sound identical, so im curious what is the determining factor?
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From: CT
Car: 86 T/A, 83 Z/28
Engine: 5.0 TPI, 350 2 X 4 bbl
Transmission: 4 speed auto, 5 speed manual
Axle/Gears: 3.23 posi, 3.73 std
Re: determining factor of exhaust/muffler sound?
There are many factors of the motor itself which will effect sound. The one in particular that most people notice immediately is the cam for example a small cam will generally have a nice smooth idle where a big cam will have that lopey race car unevenness too it. Although everything right down to the compression ratio will effect the sound somewhat. What type of construction the muffler is will give a general idea of what a motor will sound like but thats about it. Although keep in mind online sound clips are terrable representations of what a car actually sounds like. Not only is the quality of the recording almost always lacking but the distortion is terrible. Also "clipping" of the sound is a big problem with loud exhausts as the sound emitted is louder then they can record.
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From: near chicago illinois
Car: have a 92 camaro rs...in pieces
Engine: none now...probably 383 stroker
Transmission: none yet
Axle/Gears: none
Re: determining factor of exhaust/muffler sound?
I understand that a lot of recordings sound crappy, thats not what i was referring to... Ill see if i can explain my point (what im looking for) using a few examples.... X-Ravin just posted a thread, which contains this link, ill use it as an example.... http://smg.photobucket.com/albums/v2...TAwithGMMG.flv 28 seconds into the clip the guy hits the gas then lets off of it, and as the RPM's drop you hear an example of what im talking about... Dont know what words to describe it but it sounds choppy, restricted, clogged....
Thats one example... heres another... One of the links i posted earlier... http://www.youtube.com/watch?v=H4c21_HO0PE .... This one sounds pretty good at first, then around 8 seconds in he lets off the gas, n around 8 1/2 to 9 seconds, theres that sound again...whats making that sound.. its annoying....
Heres another thing, that pypes violator muffler, they have a 2 videos on their site, one is the previous one i just posted this is the other.... http://www.youtube.com/watch?v=k2Cq84fzkZY&feature=player_embedded both second gen Camaros... The recording of the red one is crappy, ill give you that. But that muffler doesnt even come close to sounding similar... The 81 sounds 10x's better than the 78... THats what im curious about.... Id like to know what muffler is going to sound good reving and dropping idle... I mean who has money to mess around with 2,3, or even 4 different mufflers ....
So the cam, the constrution, and even the compression you say.... Cau you elaborate a little, So say the compression has an effect, whats a 10.5:1 gonna do vs an 8.5:1....Sound wise??? I know the cam gives it a smoother vs choppy idle, is that it, or does it effect thickness of sound, how smooth it flows, no rectricted sound either...
Thats one example... heres another... One of the links i posted earlier... http://www.youtube.com/watch?v=H4c21_HO0PE .... This one sounds pretty good at first, then around 8 seconds in he lets off the gas, n around 8 1/2 to 9 seconds, theres that sound again...whats making that sound.. its annoying....
Heres another thing, that pypes violator muffler, they have a 2 videos on their site, one is the previous one i just posted this is the other.... http://www.youtube.com/watch?v=k2Cq84fzkZY&feature=player_embedded both second gen Camaros... The recording of the red one is crappy, ill give you that. But that muffler doesnt even come close to sounding similar... The 81 sounds 10x's better than the 78... THats what im curious about.... Id like to know what muffler is going to sound good reving and dropping idle... I mean who has money to mess around with 2,3, or even 4 different mufflers ....
So the cam, the constrution, and even the compression you say.... Cau you elaborate a little, So say the compression has an effect, whats a 10.5:1 gonna do vs an 8.5:1....Sound wise??? I know the cam gives it a smoother vs choppy idle, is that it, or does it effect thickness of sound, how smooth it flows, no rectricted sound either...
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From: CT
Car: 86 T/A, 83 Z/28
Engine: 5.0 TPI, 350 2 X 4 bbl
Transmission: 4 speed auto, 5 speed manual
Axle/Gears: 3.23 posi, 3.73 std
Re: determining factor of exhaust/muffler sound?
Ok well lets see if i can clear this up a bit as best i can anyways. In the first clip when he eases off the pedal all motors sound like that some mufflers may accentuate it more or have more of a popping sound to it but i find they all have that sound. Scientifically although this is just a educated guess what i think its related too to the fact when thats happening the motor is choked off. The motors is being reved up way high and then the carb or throttle body (the motors only source of air) is closed. The sheer momentum of the motor is what allows the motor to spin at the higher RPM despite the fact that the air being supplied isn't sufficient. As result the motor winds down but in the mean time the cylinders will not be filled with nearly as much air fuel mixture as it was at full throttle causing a weaker burn. Now for the second set of videos although those cars supposedly have the same basic exhaust system alot of details are missing. The one big piece is do they have headers? Headers will give a much louder and more of a thunderous sound or rumble depending on the muffler. Another huge deal even more significant than the headers is the catalytic converter. It sounds like the louder one has no cat or at least a high flow cat where as the quieter one probably has a regular replacement. As far as the effect of the things like cams or compression its all really relative to other parts. For example increasing the compression on a motor with a big cam would not have the same effect as a car with a small cam. Generally speaking increasing compression it will tend to make it a little louder with a sharper sound but thats only one small piece of the puzzle. Everything right down to the ignition timing changes the sound somewhat so its really hard to create a certain sound. The cam dosnt really change the sound so much other than the idle from what i can tell but its not just that it sounds rougher ( i mean it does but its not like its just a missfire) but the whole sound is different. Its hard to attribute whats the causes the resulting sound if its the roughness or is it the fact the large duration causes the exhaust valve to open sooner while the gasses are still burning but its got a unique sound that can only be describes as "lopey".
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From: near chicago illinois
Car: have a 92 camaro rs...in pieces
Engine: none now...probably 383 stroker
Transmission: none yet
Axle/Gears: none
Re: determining factor of exhaust/muffler sound?
Thanks for the detailed reply... As for the motor not getting as much air, and the motor is choked off... Do you think theres a way to address that issue, if that is in fact the case, or is it inevitable? OR do you think that if, say the compression was lower,since the motor then doesnt require an extreme amount of air/fuel, like say a high compression motor...the unburnt mixture wouldnt be that big (air vs fuel), and the cause of the exhaust sound wouldnt be so drastic, or vise versa (high compression)?... Ill throw so more questions at ya later... for now im out... Peace... Thanks again...
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Joined: Mar 2008
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From: CT
Car: 86 T/A, 83 Z/28
Engine: 5.0 TPI, 350 2 X 4 bbl
Transmission: 4 speed auto, 5 speed manual
Axle/Gears: 3.23 posi, 3.73 std
Re: determining factor of exhaust/muffler sound?
Well Im thinking its pretty much the nature of the beast kinda problem. Or at least i don't know of a solution. Your best bet would be to try and get a muffler that minimized the sound but I think pretty much every aftermarket muffler will give it that sound to one degree or another which would be a good deal more noticeable than stock. I get what your saying about lowering the compression but the thing is the fact that the carb or TB is closed and the resulting pressure differential is what slows the motor down. Changing the compression would still result in the same pressure for the most part but may affect the time it takes to go from 5k to idle.
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Car: '92 Corvette, '89 1/2-a-'Vette
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Re: determining factor of exhaust/muffler sound?
I'll take this over here...
Sorry, yes, the primary pipe lengths, or distance from head port to collector is what I was getting at with reference to the location of the collector. The combination of the syncopated firing pulses on each side, with the primary pipe length culminates in a pulse/rhythm/tone, that could set up the basis for that car's exhaust sound in general. I think.
I have no idea why the CFi could have sounded better. Could have been cam and compression but there has to have been other combos since, that had similar cam compression that don't have "that sound".
I think you car needs another muff in the pipline somewhere to knock down the loudest parts. Then, I wonder what would happen if you split it like the early OEM system, but used 2" or 2.5, rather than 1.5? Or what ever it was back then?
and had each pipe go through a "turbo" muffler. I know those don't flow great, but for sound....I wonder how that would sound on your car.
I agree, I don't think that most people could tell a CFI corvette from a TPI corvette by sound, but for sure you could tell a CFI f-body from a 305 or 350 TPI f-body. Even more interesting, when I bought my 83 it had a "factory replacement," style Walker/Dynomax exhaust (only available in the later, crossflow muffler style muffler) and it still sounded more like the twin muffler early cars then a TPI car (only a hair quieter then the twin muffler setup). Why are they so different???
2 friends of mine had an 83 and an 84, one an LG4 and the other an L69, and we did all 3 cars at the same time (exhaust at one point, headers at another point, suspension...) and we added an early TPI car to the mix eventually. Mine ended up Headman 3/4 length (most call them shortie but they're not like mustang or corvette shorties), dual cats, flowmaster y, 3" open pipes I described earlier. the other 83 got ebrock TES + the early dynomax cat back (single 3" muffler and single 3" tailpipe), the 84 got Hooker 3/4 headers, later dynomax cat back (essentially mild steel TTL), and the TPI got edlebrock TES + SLP TTL. My CFI remained distinctly crossfire sounding, the other 3 were pretty hard to tell apart, I remember that the TPI car ended up quieter than the rest.
I kind of wonder if part of the CFI sound is compression and cam. They were advertised as having 9.8:1 with iron heads, and the cam was similar to the later TPI cam with less LSA.
This is for sure a thing. There used to be a knockoff of the Hooker Aerochamber that I put on my '92 K1500 2 door blazer. That had an interesting exhaust- driver's side Y into the passenger side, from there straight back to the muffler (cat went in that pipe but I removed it), straight back out of the muffler, 1 bend to the outlet. That one sounded BLAAAAA, almost like a bad open exhaust (muffler fell off) on axis with the tailpipe, and sounded deep, Aerochamber like off axis.
I'm not sure what to make of that, I mean the f-body shorter headers are closer to the corvette then the rest, for sure on the driver's side where the collector is typically below 3/5 and against the back of the K member. I guess they don't have the symmetry of the c4 corvette headers.
Mustangs sound pretty much the same with snake's nest equal-length headers as well as the standard non-equal ones. They don't sound that different outside the car with dumps before the axles either
2 friends of mine had an 83 and an 84, one an LG4 and the other an L69, and we did all 3 cars at the same time (exhaust at one point, headers at another point, suspension...) and we added an early TPI car to the mix eventually. Mine ended up Headman 3/4 length (most call them shortie but they're not like mustang or corvette shorties), dual cats, flowmaster y, 3" open pipes I described earlier. the other 83 got ebrock TES + the early dynomax cat back (single 3" muffler and single 3" tailpipe), the 84 got Hooker 3/4 headers, later dynomax cat back (essentially mild steel TTL), and the TPI got edlebrock TES + SLP TTL. My CFI remained distinctly crossfire sounding, the other 3 were pretty hard to tell apart, I remember that the TPI car ended up quieter than the rest.
I kind of wonder if part of the CFI sound is compression and cam. They were advertised as having 9.8:1 with iron heads, and the cam was similar to the later TPI cam with less LSA.
This is for sure a thing. There used to be a knockoff of the Hooker Aerochamber that I put on my '92 K1500 2 door blazer. That had an interesting exhaust- driver's side Y into the passenger side, from there straight back to the muffler (cat went in that pipe but I removed it), straight back out of the muffler, 1 bend to the outlet. That one sounded BLAAAAA, almost like a bad open exhaust (muffler fell off) on axis with the tailpipe, and sounded deep, Aerochamber like off axis.
I'm not sure what to make of that, I mean the f-body shorter headers are closer to the corvette then the rest, for sure on the driver's side where the collector is typically below 3/5 and against the back of the K member. I guess they don't have the symmetry of the c4 corvette headers.
Mustangs sound pretty much the same with snake's nest equal-length headers as well as the standard non-equal ones. They don't sound that different outside the car with dumps before the axles either
I have no idea why the CFi could have sounded better. Could have been cam and compression but there has to have been other combos since, that had similar cam compression that don't have "that sound".
I think you car needs another muff in the pipline somewhere to knock down the loudest parts. Then, I wonder what would happen if you split it like the early OEM system, but used 2" or 2.5, rather than 1.5? Or what ever it was back then?
and had each pipe go through a "turbo" muffler. I know those don't flow great, but for sound....I wonder how that would sound on your car. Supreme Member
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From: Park City, UT
Car: '92 Corvette, '89 1/2-a-'Vette
Engine: LT1, L400
Transmission: ZF6, T5
Axle/Gears: 3.45, 3.31
Re: determining factor of exhaust/muffler sound?
Jesus Christ. I was trying to reply to the thread above, hit the "end" button on my keyboard and got "I-Mac'd" by my POS Mac. It scrolled ALL the way down to the bottom of this 15 year old thread. Love this turd of a computer.
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