exhaust engineering.

Real tech discussion on design, fabrication, testing, development of custom or adapted parts for Pontiac Fieros. Not questions about the power a CAI will give.

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ericjon262
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exhaust engineering.

Post by ericjon262 »

there are lots of things about my car I don't like, one of them is the exhaust. it sounds good, but the routing isn't very good, and doesn't leave much room for cable routing or movement. so, something on the list for the next time the cradle is out, is to put a better planned, and hopefully more efficient, exhaust on that will help spool the turbo faster. at this point, I've gone as far as mapping out a header flange in sketchup, and began on a 3-1 header for the rear, with the collector ending just barely past the head. it's not exact equal length by any means, but all cylinders are within one inch of each other. and I could get the brought down to probably about 1/2" with a little bit more work.

I'm working on another design that will bring the end of the collector closer to the end of the head for better packaging.

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I'm either going to do this or a simple log type manifold. either way, construction will be stainless weld el's, probably in 321.I haven't modeled a log yet, and probably won't. more work than it's worth when simple measurements will tell me what I need to know.

anyone have any input?
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Emc209i
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Re: exhaust engineering.

Post by Emc209i »

Don't do logs. Build manifolds.
ericjon262
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Re: exhaust engineering.

Post by ericjon262 »

well, right now my goal is to keep primary volume/length to a minimum, and each primary as close to equal as possible. while packaging in the smallest amount of space possible. I've made some progress on the next rendering but I'm only working on it in my spare time/at night, so progress is slow.
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ericjon262
Posts: 2819
Joined: Mon May 24, 2010 5:34 pm
Location: Aiken, SC

Re: exhaust engineering.

Post by ericjon262 »

on a side note, centerline radius on a 45* weld el is not quite what it is normally listed as... the 45* els are listed on most sites as 1.125" CLR, if you draw a 45* 1.125" CLR arc, your el will be way shorter than an actual 45* weld el. from a design perspective, this is very important info...

now this can go to the scrap pile...


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left vs right is a huge difference...

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The Dark Side of Will
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Re: exhaust engineering.

Post by The Dark Side of Will »

Have you calculated what the actual CLR is? Where are you sourcing your weld el's?

Have you checked out www.onshape.com ?

I assume this is primarily a packaging driven exhaust design for your turbo, right?
ericjon262
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Location: Aiken, SC

Re: exhaust engineering.

Post by ericjon262 »

The Dark Side of Will wrote:Have you calculated what the actual CLR is? Where are you sourcing your weld el's?

Have you checked out http://www.onshape.com ?

I assume this is primarily a packaging driven exhaust design for your turbo, right?
packaging is one of the bigger concerns, I want to move the turbo away from the strut tower a couple of inches. If I can make it spool faster in the process, hellz yeah! I'm looking at acerace right now for the el's

http://www.aceraceparts.com/collections ... s-weld-els

I called them and asked about actual dimensions, because the el's pictures looked like alot larger of a radius than the ones in my sketchup drawing. they sent me an email from their manufacturer's spec page.

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from what I can see, the true CLR on the 45* el's, is 2.25, like the large radius 90* el's, which makes enough sense, 90/2=45...

the onshape program looks pretty cool, I'm gonna check it out.
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
ericjon262
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Re: exhaust engineering.

Post by ericjon262 »

still not equal length, getting it closer though. I need to take about 1.5" out of the leading runner, and add about 1" to the shortest to get them pretty close. right now, that appears completely doable...

Image
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ericjon262
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Re: exhaust engineering.

Post by ericjon262 »

lots of little tweaks on the rear, but it's getting closer...

Image
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ericjon262
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Re: exhaust engineering.

Post by ericjon262 »

Version 3.0...

Image

not really all that close to equal length, but as the gas velocity goes up, the distance becomes a smaller and smaller part of the big picture. as an added benefit, this design would cost quite a bit less than most of the others previously shown. I can potentially get them closer to equal length by adding spacers in the 180* bend in the #6 primary.it would be super awesome to have a rendering of a 3500 F23 setup right now to do a digital test fit... oh well, just have to take lots of measurements on the one in the garage and verify fitment that way...
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
The Dark Side of Will
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Re: exhaust engineering.

Post by The Dark Side of Will »

How many spare parts do you have?

The block itself isn't that hard to mock up if you know the block deck, bank angle and width across the deck and pan rails.
The head can be approximated by assuming the exhaust flange is 90 degrees to the block deck and then adjusting by the distance from the block deck to one of the exhaust flange bolt holes.
ericjon262
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Re: exhaust engineering.

Post by ericjon262 »

I have a set of heads and an intake, that's about it. the exhaust ports are 90 degrees to the deck, which puts the flange 30 degrees off vertical outboard. I thought about doing a very basic drawing of the engine, to give an idea of positioning of the exhaust relative to the block, but it would require a huge amount of work that I don't feel like doing right now.

I'm 90% sure the last design will be the one I roll with. I'm trying to figure out what I'm gonna do for a turbine housing, I'd like to do VGT to some degree, and I have a couple of ideas that I might be able to make work that could provide some pretty epic results. it would be based on a VGT setup Borg-Warner prototyped a while back, but as a bolt on for a divided T4 turbine housing.

https://youtu.be/J06nj5-B_AE

this one looks pretty cool too, I wonder what types of changes take place in the blading when going to a axial flow turbine. to me, it looks like the turbine is more of a reaction type in this design, but it's hard to tell without a good close up of the blading.

https://youtu.be/Gz0qZpxXnLg
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
ericjon262
Posts: 2819
Joined: Mon May 24, 2010 5:34 pm
Location: Aiken, SC

Re: exhaust engineering.

Post by ericjon262 »

Here's version 3.1, my biggest concern is spark plug access. with this design the number 6 primary might be in the way of access to the number 6 spark plug. the longest length is just under 10", the shortest is just over 8"

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"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
ericjon262
Posts: 2819
Joined: Mon May 24, 2010 5:34 pm
Location: Aiken, SC

Re: exhaust engineering.

Post by ericjon262 »

started on the front manifold. lots of tweaking to do still...

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"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
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