the best exhaust article EVER...maybe

[Frankenchevy]

https://www.chevydiy.com/chevy-small-block-engine-guide-exhaust-systems/

they include a section on tuning secondary tube length. they use a resonator box to blind the engine to the mufflers or whatever comes after the resonator box. say your engine's optimal secondary length is two feet, you install a resonator which is just fancy for something that disrupts the exhaust pulse to optimize flow. most people talk about resonators as a type of muffler, when the science shows they have a purpose in a tuned exhaust in conjuntion with the use of a muffler.

so the correct order would be header/manifold, collector, secondary tube length, resonator, pipe, muffler. does a crossover such as an x-pipe replace what the resonator does or should I run resonators, then x-pipe, then muffler? most people suggest running the crossover as soon as possible after the headers for max scavenging effect. this is also where the article says to place resonators.

maybe the book was written before x and h-pipes were popular. if anyone has some actual knowledge to validate any of this, it would be greatly appreciated. I already have the parts sitting around so I could try it both ways. I just don't want anymore welds than necessary on my exhaust. I'm kind of weird with my OCD.

 

[Craig 85]

Good article. That's a LOT of numbers! I looked at the copy right dates for his book and they are 1999 and 2009. I don't know if the 2009 is just a reprint.

I was always told that you wanted a cross over about 18" back from the collectors (This was before X pipes were introduced). X pipes help with scavenging, but placement on a 4x4 chassis may not put it at the optimum location.

 

[4WDKC]

Good article. That's a LOT of numbers! I looked at the copy right dates for his book and they are 1999 and 2009. I don't know if the 2009 is just a reprint.

I was always told that you wanted a cross over about 18" back from the collectors (This was before X pipes were introduced). X pipes help with scavenging, but placement on a 4x4 chassis may not put it at the optimum location.

its not just limited to 4x4s, its hard to put it 18" behind anything with a transmission attached. Love and hate that article as it has always made me want to redo exhaust on my cars.

 

[Iowan]

https://www.chevydiy.com/chevy-small-block-engine-guide-exhaust-systems/

they include a section on tuning secondary tube length. they use a resonator box to blind the engine to the mufflers or whatever comes after the resonator box. say your engine's optimal secondary length is two feet, you install a resonator which is just fancy for something that disrupts the exhaust pulse to optimize flow. most people talk about resonators as a type of muffler, when the science shows they have a purpose in a tuned exhaust in conjuntion with the use of a muffler.

so the correct order would be header/manifold, collector, secondary tube length, resonator, pipe, muffler. does a crossover such as an x-pipe replace what the resonator does or should I run resonators, then x-pipe, then muffler? most people suggest running the crossover as soon as possible after the headers for max scavenging effect. this is also where the article says to place resonators.

maybe the book was written before x and h-pipes were popular. if anyone has some actual knowledge to validate any of this, it would be greatly appreciated. I already have the parts sitting around so I could try it both ways. I just don't want anymore welds than necessary on my exhaust. I'm kind of weird with my OCD.

That was an Exhausting read.........

 

[Frankenchevy]

its not just limited to 4x4s, its hard to put it 18" behind anything with a transmission attached. Love and hate that article as it has always made me want to redo exhaust on my cars.

I really does. if you even try to search about resonators on the internet, everyone treats them as a lightweight muffler and it always tossing them out. turns out, they are for tuning your secondary length. this is why I'm wondering if x pipes have now taken their place.

as for x pipe placement, I plan on going up in elevation with the secondary pipe to match the elevation change of the frame going rearward. I want to run the x pipe above and just rearward of the front u joint of the rear drive shaft, then back out to parallel to the frame rails where my mufflers will go, then up and over the rear axle. I want it quiet but efficient.

still trying to figure out if a resonator should be installed upstream from the x pipe based on that article. I found it interesting that no mention of crossovers were mentioned but this picture looks an awful lot like a crossover application. I'd like if they had shown a cross section of the pipe.

You must be registered for see images attach

 

[4WDKC]

I really does. if you even try to search about resonators on the internet, everyone treats them as a lightweight muffler and it always tossing them out. turns out, they are for tuning your secondary length. this is why I'm wondering if x pipes have now taken their place.

as for x pipe placement, I plan on going up in elevation with the secondary pipe to match the elevation change of the frame going rearward. I want to run the x pipe above and just rearward of the front u joint of the rear drive shaft, then back out to parallel to the frame rails where my mufflers will go, then up and over the rear axle. I want it quiet but efficient.

still trying to figure out if a resonator should be installed upstream from the x pipe based on that article. I found it interesting that no mention of crossovers were mentioned but this picture looks an awful lot like a crossover application. I'd like if they had shown a cross section of the pipe.

You must be registered for see images attach

AS i understood it the resonator box is open and acts like the crossover/xpipe therefore one wouldnt be needed but, what is in the resonator box? Is it empty, glass matt, chambered?

 

[Frankenchevy]

I was thinking of putting a hollow box running side to side just past the crossmember where the cab and bed meet where both primaries enter and share pulses, while also scrambling the flow. I'm not sure if mixing the banks in a big dumb box is the way to go, might completely kill velocity. I guess I need to keep tapping away on google. most info I come up with is in no way scientific and as previously stated, most people are viewing resonator boxes as another form of muffler...

 

[Frankenchevy]

AS i understood it the resonator box is open and acts like the crossover/xpipe therefore one wouldnt be needed but, what is in the resonator box? Is it empty, glass matt, chambered?

this is how I saw it too, and again no mention of crossovers. so they may indeed fill the role that resonators once did.

my main parameters are in this order: 1. economy, 2. quietness without totally killing power

 

[4WDKC]

this is how I saw it too, and again no mention of crossovers. so they may indeed fill the role that resonators once did.

my main parameters are in this order: 1. economy, 2. quietness without totally killing power

dont use chambered mufflers ie most versions of flowmaster, a straight through design is quieter at idle and cruise speeds. A friend has some one his 454 equipped car and it droned so bad he had to add resonators to the system in the tail pipes.

 

[yevgenievich]

Having a resonator box or an x pipe should be relatively equivalent. The idea is to get a pressure drop that helps scavenge from the secondaries. Resonator box probably more than x pipe

 

[Frankenchevy]

Having a resonator box or an x pipe should be relatively equivalent. The idea is to get a pressure drop that helps scavenge from the secondaries. Resonator box probably more than x pipe

just to clarify, you're suggesting that a resonator at the end of the tuned length secondary is more effective than an x pipe?

 

[yevgenievich]

just to clarify, you're suggesting that a resonator at the end of the tuned length secondary is more effective than an x pipe?

Basic understanding that I have gathered from related materials and general understanding is that a large resonator that joins two secondaries would theoretically be better. The basic flow indicates that the exhaust will flow better if it is dumped in to a lower pressure chamber. The tuning will also usually give benefit in a very specific rpm band.
As for mufflers, a straight through muffler that has outer packed chamber with perforations in between will be quieter at lower rpms, louder at higher rpms and actually flow greater at higher rpms than a plain pipe.

Edit: edited for clarification

 

[Frankenchevy]

A large resonator that joins two secondaries would theoretically be better. The basic flow indicates that the exhaust will flow better if it is dumped in to a lower pressure chamber. The tuning will also usually give benefit in a very specific rpm band. There is also an idea that a straight through muffler that has outer chamber with perforations in between will be quieter at lower rpms, louder at higher rpms and actually flow greater at higher rpms than a plain pipe.

don't make fun of my 30 second printer paper sketch, but something like this?

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edit: I could build the box to fit right behind the crossmember where the cab and bed meet. the article points out that the resonator should be equal to the displacement of the engine for a v8 application, i.e. 350cubic inches. it's not clear if that's per side or total. it states that as a minimum. even 700 cubic inches is a relatively small chamber.

 

[yevgenievich]

don't make fun of my 30 second printer paper sketch, but something like this?

You must be registered for see images attach

I would eliminate that angle on incoming pipes if possible, but it is basically an H pipe. The initial picture you had to me would be a better solution, but what you have is probably the next best thing. Would need to get a fluid dynamics person to figure out the sizes or just give it a try sizing to physical limitations. Have to think of the engine firing events, the speed of the valve closing and opening and speed of gasses traveling as well.
Engine masters have done some testing of different configurations already. For exception of making the h pipe section larger.

 

[Frankenchevy]

science n'sheit