Exhaust chamber design. I'm stuck, please help!

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faytmorgan
faytmorgan
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Joined: 12 Nov 2012, 07:33

Exhaust chamber design. I'm stuck, please help!

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On my lonesome I have been working on a set of mufflers that don't sound like fecal matter. I am having a difficult time finding just the mufflers (race mufflers). I DO NOT want an entire exhaust system. I do have the capability of fabing up mufflers, I have custom made equal length headers to an x pipe thus far. I DO NOT want the mufflers to have those two little connections keeping them together. I will be making this a side exit.

The motor is a carbed 5.5 lt small journal sbc. Should be able to make power to 7800 or so rpm.

I am looking for the highest frequency/note/tone/pitch I can get. I very much enjoy the higher, crisper, cleaner sound the euroapean v8 makes. I hate with a passion the rumble of the harley/dumptruck American v8. I have heard flowmasters on these cars. I don't know if it was the particular flowmaster series or what. But that m3 was a dumptruck. I am trying to avoid that.

Sounds like a chevy small block doing a dyno pull to me...
http://www.youtube.com/watch?v=Y-mGGf5Ncx8

BMW E92 M3 Eisenmann race exhaust - YouTube

amazing high frequency sound
iPE Innotech E92 M3 Evolution Valvetronic Exhaust System F1 Sound - YouTube

BMW M3 iPe Valvetronic Exhaust Sound (Drive By, Downshift, Rev) - YouTube

Here is a cutaway of a corsa muffler.

http://s805.beta.photobucket.com/user/P ... ml?filters[term]=recent&filters[primary]=images

I am rather sure that the chambers in the muffler can be designed as such to reflect frequencies to cancel out the unwanted frequencies. I just can't find the math anywhere to determine the dimensions of the chambers.

I am working with 17.9 inch long primary tubes that are 1 and 5/8 in diameter, they go into a 2.5 inch collector, that then goes into a 3 inch x pipe, that will then go directly to the side exit mufflers. I am keeping it as short as possible to help retain the sound I am after.

This is what I am avoiding.
Magnaflow Exhaust on a Chevy Truck - YouTube

Same motor different car different mufflers...
http://www.youtube.com/watch?v=IVWZMKMmjMQ

So does anyone know how to design the muffler to achieve this? Or designing a resonator to do this? Or simply the chambers inside the muffler to do this?

I am so stuck. Also I don't think a helmholts resonator of any kind will do the trick. that would only cancel out the freq. I think this is more like a musical instrument where the sound entering is not going to be the sound at the bell of the horn coming out.

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strad
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Joined: 02 Jan 2010, 01:57

Re: chamber design. I'm stuck, please help!

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I am looking for the highest frequency/note/tone/pitch I can get. I very much enjoy the higher, crisper, cleaner sound the euroapean v8 makes.
Then skip the hassle and go with Bassani.
To achieve anything, you must be prepared to dabble on the boundary of disaster.”
Sir Stirling Moss

faytmorgan
faytmorgan
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Joined: 12 Nov 2012, 07:33

Re: chamber design. I'm stuck, please help!

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Bassani is no where near the high freq that the ipe f1 exhaust produces- otherwise, I would.

mx_tifoso
mx_tifoso
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Joined: 30 Nov 2006, 05:01
Location: North America

Re: chamber design. I'm stuck, please help!

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So you only care about the sound and not at all about the actual performance?

And that M3 with the iPe is eargasmic! I was actually smiling from ear to ear while hearing it.

Although the comparisons or mentioning of the american V8 sounds, especially the 90's Silverado, is a bit unecessary since we're talking about M3's right? :lol:
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flynfrog
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Joined: 23 Mar 2006, 22:31

Re: chamber design. I'm stuck, please help!

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faytmorgan wrote:Bassani is no where near the high freq that the ipe f1 exhaust produces- otherwise, I would.
you are not going to get f1 sounds out of an engine that doesn't rev even half as much. The chamber you would need is not going to be a simple geometry you are basically going to need to take half of each pulse and phase shift it while ignoring the other half pulses.

faytmorgan
faytmorgan
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Joined: 12 Nov 2012, 07:33

Re: chamber design. I'm stuck, please help!

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mx_tifoso wrote:So you only care about the sound and not at all about the actual performance?

And that M3 with the iPe is eargasmic! I was actually smiling from ear to ear while hearing it.

Although the comparisons or mentioning of the american V8 sounds, especially the 90's Silverado, is a bit unecessary since we're talking about M3's right? :lol:
The ipe f1 exhaust is the closest thing I have heard to an f1 engine. I have a theory that it has more to do with their x pipe design.

see the hole in the middle of the x pipe?
http://i.imgur.com/batEA.jpg

I know that the chambers have to be designed that way, I just don't know the math. That is what I am looking to find is the math. I figure I would design it as corsa does with the rsc. But I have no idea how to calculate the chamber dimensions within the muffler.

olefud
olefud
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Joined: 13 Mar 2011, 00:10
Location: Boulder, Colorado USA

Re: Exhaust chamber design. I'm stuck, please help!

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I’m not sure as to just what you have in mind. But if, you don’t have 180º headers, you’ll have a beat rather than a rip in the sound.

langwadt
langwadt
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Joined: 25 Mar 2012, 14:54

Re: chamber design. I'm stuck, please help!

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flynfrog wrote:
faytmorgan wrote:Bassani is no where near the high freq that the ipe f1 exhaust produces- otherwise, I would.
you are not going to get f1 sounds out of an engine that doesn't rev even half as much. The chamber you would need is not going to be a simple geometry you are basically going to need to take half of each pulse and phase shift it while ignoring the other half pulses.
and F1 is flat plane, most road cars are cross plane

look at the crazy manifold on an old GT40 vs. a ferrari 355

faytmorgan
faytmorgan
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Joined: 12 Nov 2012, 07:33

Re: Exhaust chamber design. I'm stuck, please help!

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thing 1.180 degree headers are only efficient to about rpm.

thing 2. the s65 does not use 180 degree headers

thing 3. the s65 is a cross plane v8 not a flat plane like ferrari and zonda etc.
----------------

those 3 things above are NOT thinking out side the box. The ipe f1 exhaust system as posted in my original post uses factory headers and down pipes, it does not have cats, it uses an x pipe to a axle back muffler set. There is also a video I posted that shows what the s65 sounds like with just the headers whilst it is on the dyno, and it sounds almost identical to a chevy 302 at 8k rpm.

This is in relation to the exhaust past the headers to be acoustically tuned to produce a higher pitched exhaust note. Kreisseg, Ipe f1, rpi exhaust, essienman, and megan racing have exhaust that ALL sound higher pitched. the ipe is the highest pitched of them all. All of these exhaust utilize an x pipe, rear axle back, and retain the factory downpipes and headers. So when I this is possible why don't you read the post I posted, listen to the links, and then see what I am trying to do.

it will NOT sound exactly like an f1 car, it will get very high in frequency level. This has been done, I am attempting to understand HOW it was done. I figured on a website dedicated to f1 car design that someone would know the technology in acoustically tuning the exhaust....

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strad
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Joined: 02 Jan 2010, 01:57

Re: Exhaust chamber design. I'm stuck, please help!

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You aint gonna get the sound you want from a small block V8
To achieve anything, you must be prepared to dabble on the boundary of disaster.”
Sir Stirling Moss

faytmorgan
faytmorgan
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Joined: 12 Nov 2012, 07:33

Re: Exhaust chamber design. I'm stuck, please help!

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strad wrote:You aint gonna get the sound you want from a small block V8

You just saw a video of the s65 sounding exactly like a 302. and then you saw a clip of it with the ipe f1 exhaust. OR you didn't pay attention. Also why don't you listen to a corvette with tubi exhaust. They sound very close to this, very slight difference. So THAT tells me you are wrong and I am right. And you have nothing to back anything up of what you are saying.

I am done with this site. Obviously there is no knowledge here.

garygph
garygph
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Joined: 13 Oct 2008, 14:25

Re: Exhaust chamber design. I'm stuck, please help!

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I am done with this site. Obviously there is no knowledge here.
That has to be the most ridiculous statement I have read here and there have been some real blinders. I have taken years of pleasure reading and learning from some very very clever, experienced, educated, intuitive people on this site. That comment of yours just totally highlighted the waste of energy anybody has spent trying to help you.