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Exhaust Note/ Proposition

M

MONSTROSITY505

New member
Hello all. I'm new here, so bear with me. I have a proposition. I'm on a mission to make the 3800's exhaust note sound nice. I've found a video with a Holden Commodore VT (V6, 3.8L), and the car has straight pipe duals. I've been searching as much as possible to find out why it sounds so amazing compared to the 3.8's over here.. I was thinking the headers could be a factor to this, but it could also be the drivetrain difference. I have taken note that the headers are different on the Commodore. They are seperate.
This is just a wild theory, but could that have anything to do with the difference of sound? I've also found a video with a Commodore straightpipe exhaust note. I'm no expert, so go ahead and give me an in depth explanation of why this is.

Here's the video: https://youtu.be/JmnoXNJjiSs
 


^^^^^ that's a very good example

I want to do something similar eventually, I would love to hear that with a big cam... Lol
 
SaukRapids said:
GIYF ~ "3800 true duals"

The white GTP that comes up sounds like total ass, imho. https://www.youtube.com/watch?v=ctoJw8Qy-NE

A few forum threads came up so there's probably been others try different pipe diameter, muffler, etc.
Click to expand...
That thing sounds horrible.


Just put a cam with a 3 inch exhaust setup. It'll sound ok, not great but ok. Best you can get with a gp.

If you want better buy a gxp or another v8 car. You'll waste time, effort and more importantly money trying to reinvent the wheel to make a fwd 3800 sound great.
 
MONSTROSITY505 said:
I have taken note that the headers are different on the Commodore. They are seperate. I'm no expert, so go ahead and give me an in depth explanation of why this is.

Here's the video: https://youtu.be/JmnoXNJjiSs
Click to expand...
It helps if I remember that air is a fluid to understand exhaust. Each time a cylinder fires, a pulse travels down the exhaust. Separating the "pulses" is good for flow on any engine, right? V8, V6, V12..doesn't matter. The problem with a 3800's "sound" is that it's created by the bore, stroke and timing of the architecture. Also very simply, you can think of it as running two separate inline 3 cylinder 4 strokes next to each other. Do you think that could ever sound good?

I'm with chrsmi1.

Oh, and that video? That could be anything. I mean, you can't see the engine. Just have to take their word that it's what they say it is. Not everyone with a camera's honest.
 


I've been getting some feedback from other people and so far the only way to make it sound "nice" (IMO) is to make true duals. The problem I'm hearing is the clearence issue. And apparently the turbo setup would be the only way to get for the sound I'm trying to emulate. The thing I dont understand is, isn't it possible to just get the connected headers, and divide the connection into two while at the same time keeping the tubes right next to each other? Just look at ZZP's headers for example. What if you could cut into it, and just have someone add a middle piece. Would that still count for true duals?
 
I think if you ran a single exhaust from a semi-turbo style crossover, just use PLOGs for the front and rear, that would make the "headers" equal length and give you a better sound... It's not "true" duals, but it will sound like a turbo exhaust without the turbo noises.

Or you could build a custom "crossover", maybe a Y pipe that exits towards the driver's side and runs the same route as the turbo downpipe...

Anything that would resemble a true dual exhaust will have to be custom fabricated.
 
they best way to get a 3800 to sound decent is to remove the screwy things from the intake of the engine and install a whirlly thing on the exhaust
 


Lol I was looking at a RWD conversion somebody did on here a while ago, that's really the only way to get true duals in a GP. lol
 
Anybody ever messed with a side-resonator style exhaust? I've read a lot of good things about them on 350z's.

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SaukRapids said:
It helps if I remember that air is a fluid to understand exhaust. Each time a cylinder fires, a pulse travels down the exhaust. Separating the "pulses" is good for flow on any engine, right? V8, V6, V12..doesn't matter. The problem with a 3800's "sound" is that it's created by the bore, stroke and timing of the architecture. Also very simply, you can think of it as running two separate inline 3 cylinder 4 strokes next to each other. Do you think that could ever sound good?
Click to expand...

I am also interested in getting an L67 to sound good (but in a RWD). I think that Porsche flat 6's sound nice - so I wonder how much of the difference is between the flat6/v6, how much is flow, how much is cam, how much is exhaust design, etc? And maybe it's just the difference in how much engineering effort was put into getting a good sound. I would think Porsche spent time on this and GM... maybe not so much.
 
I like the J-pipe idea. I kinda wanna look and see how it works now, lol.

I'll try and be brief with my uneducated (I'm not a hydro-dynamics major) perspective.

I agree that the difference when I specifically think of another 3.8 exhaust compared to a 3800 is interesting. The higher profile engines that come to mind are newer Porches and the Nissan GT-R. All three have different bore and stroke, but more importantly, different valve trains. As you mention, lift, duration, valve size, number of valves, spring rate, and even seat angle will affect what air comes out. What air goes in, or is forced in (temp, pressure, volume) will affect the ..uhm "power"? of the pulse going down the pipe.

Interestingly, I think a J pipe tries to alleviate rasp by giving overlapping gasses a place to go. See, I think the root cause of rasp or rap (in my experience with pickups) is exhaust flow running into itself very near the engine, causing air and hence sound to bounce around inside the exhaust (maybe even air "slapping" against itself and/or the valves opening and closing). Does that make any sense?

I guess the Porche would have the shortest exhaust route, giving it a unique sound. Feel free about your perspective. This is just from my limited understanding.
 
I think it's the fact that the 3800 was derived from a V8 originally, so it's "missing" two pistons. That's where the 3800's good sounding exhaust note went. Lol
 
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