Is that Tim's handy work? Boy has some great AL tig skills.
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thats gonna make redoing the intercooler piping interesting......if the TB faces up we might not be able to close the hood.
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Originally Posted by disturbedfan121
(Post 327471)
thats gonna make redoing the intercooler piping interesting......if the TB faces up we might not be able to close the hood.
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I love it. Can't wait to see that on a car.
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The 90deg turn out or that TB makes baby jesus cry...
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Originally Posted by neogenesis2004
(Post 327498)
The 90deg turn out or that TB makes baby jesus cry...
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Any thoughts on creating something that would allow a larger than stock throttle body to be installed? I really hate the 3rd design.
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Any one of these manifolds will allow for a larger TB to be installed, just modify the flange accordingly.
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3 Attachment(s)
The only thing I really found suggesting a raised velocity stack was when the stack inlet radius was toroidal (meaning, not a constant radius). For a constant radius inlet, the stack was suggested to be flush against the floor.
Originally Posted by Braineack
(Post 327201)
in regards to this manifold design:
http://img68.imageshack.us/img68/7941/velocitycw7.png Attachment 210182 Attachment 210183 Attachment 210184 |
Originally Posted by apexonyou
(Post 327474)
i love it. Can't wait to see that on a car.
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Originally Posted by disturbedfan121
(Post 327471)
thats gonna make redoing the intercooler piping interesting......if the TB faces up we might not be able to close the hood.
Stephanie |
Originally Posted by JayMX5
(Post 327510)
Any thoughts on creating something that would allow a larger than stock throttle body to be installed? I really hate the 3rd design.
Stephanie |
would be cool to see how mine's coming along :cry:
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Stephanie, how compatible will these be with oem equipment? I know EGR is gone (which is no problem), but what about vacuum lines and PCV?
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run the pcv to a catch can or just let it blow oil onto the IM lol
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I was playing some more.
I really like the idea of a tapered IM. With what I'm finding, it's providing the best flow into #4. A little too good in this certain case: http://www.boostedmiata.com/projects...d-nostacks.jpg I removed the stacks...seems like they really helped create a larger area to pull airflow from. With the stacks back in place I got flow back into #1. http://www.boostedmiata.com/projects...tacksfloor.jpg so then I thought, why not move the TB inlet back 2" inches to see what difference it had...in the same conditions it flow like the first one...it's almost like the stack of #1 needs to be right at the inlet to work. http://www.boostedmiata.com/projects...ongerinlet.jpg so at this point I thought angling the TB would be the best to retain that lost flow but as to not disturb the airflow to the rear of the manifold. Which seemed to help. http://www.boostedmiata.com/projects...ngledinlet.jpg I was really starting to like this shape, so I went crazy with teh inlet and did the common "teardrop" shape and saw pretty good results. http://www.boostedmiata.com/projects...ngledinlet.jpg |
Originally Posted by Braineack
(Post 327905)
so then I thought, why not move the TB inlet back 2" inches to see what difference it had...in the same conditions it flow like the first one...it's almost like the stack of #1 needs to be right at the inlet to work. http://www.boostedmiata.com/projects...ongerinlet.jpg |
your final design reminds me of some of the versions made for the sr2d0et. what if you make the tb 2" further out from #1 and not closer?
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You can see I tried that between images 2 and 3.
The differences between all the above are 1. no stacks. 2. stacks 3. 1.3" added between wall and stacks 4. 14° angle on inlet. 5. crazy angled inlet and teardrop taper. I mean hell knows if I'm setting up these pressure boundaries correctly, but it's pretty obvious which variation flows evenly the best. This has me thinking about something, going to try a different inlet variant. |
Originally Posted by Braineack
(Post 327968)
You can see I tried that between images 2 and 3.
The differences between all the above are 1. no stacks. 2. stacks 3. 1.3" added between wall and stacks 4. 14° angle on inlet. 5. crazy angled inlet and teardrop taper. I mean hell knows if I'm setting up these pressure boundaries correctly, but it's pretty obvious which variation flows evenly the best. This has me thinking about something, going to try a different inlet variant. |
Originally Posted by y8s
(Post 327971)
put the ridge in!! and radius the transition between the TB area and plenum.
this however seems to be a great design....and could easily work without moving headlights out of the way: The basic shape of the plenum is the same, only with a 45* downward tapering inlet. http://www.boostedmiata.com/projects...nlet-shape.jpg This seems to allow the velocity to stay high all the way to #4 and the airflow curls into the runners. If you look at the stock 1.6L manifold, it kinda does the same thing. The time between when #1 and #4 get airflow is much closer than any other design I've simulated. http://www.boostedmiata.com/projects...t-velocity.jpg flow trajectories http://www.boostedmiata.com/projects...nwardinlet.jpg http://www.boostedmiata.com/projects...trajectory.jpg |
So wheres the Rapid Prototype to test on a cylinder head for flow? :D
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1 Attachment(s)
i scanned my face. please check my flow.
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Man you have some seriously screwed up eyelids.
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Originally Posted by cjernigan
(Post 327995)
Man you have some seriously screwed up eyelids.
hard to do by yourself when you can't see! |
Makes sense now. Now scan something awesome in hi-res so we can really be wowed. (Not that any 3D scanning isn't amazing enough.)
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sorry, alls i got for now is a few rotary wing helmets. might interest samnavy but that's prolly it.
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needs more IM pictures and idears.
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Originally Posted by elesjuan
(Post 327986)
So wheres the Rapid Prototype to test on a cylinder head for flow? :D
Here is an example: http://forums.nasioc.com/forums/show....php?t=1600687 The walls look a bit thin for a working prototype for this one. I think it may just be a test fit for an aluminum casting. |
Originally Posted by ZX-Tex
(Post 328019)
Word. I think glass-filled ABS, either FDM or SLS formed, is used pretty commonly for test manifolds. Being a mostly dry-flow manifold helps too. ATI in Austin could do it easily, though they are not cheap. I would guess $3-$5K. The size makes it expensive. I do know a guy who has a rapid prototype source in China that is really cheap.
Here is an example: AMS Subaru Intake Manifold: Work in Progress - NASIOC The walls look a bit thin for a working prototype for this one. I think it may just be a test fit for an aluminum casting. I need to get my escort cylinder head reassembled, at least on the intake side to build a ghetto flow bench. I've been wanting to try and build and test something like this for since my 2.3 Turbo days. Just never had half the equipment needed for this until now. |
Originally Posted by elesjuan
(Post 327986)
So wheres the Rapid Prototype to test on a cylinder head for flow? :D
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I say pictures or ban!
Unless it is proprietary of course. I can appreciate that. |
Originally Posted by ZX-Tex
(Post 328158)
I say pictures or ban!
Unless it is proprietary of course. I can appreciate that. I too wanna see what an ABSURDFLOW!!@&$ intake manifold looks like.. Probably pretty crazy :D |
This is some interesting stuff!
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Originally Posted by elesjuan
(Post 328179)
:)
I too wanna see what an ABSURDFLOW!!@&$ intake manifold looks like.. Probably pretty crazy :D Tim @ BEGI :ne: Turbotim. Unless, of course, BEGI hires me, in which case there'd be two Tim's at BEGI ;) The only intake mani I've welded is the one on my car, and I wouldn't consider it absurdflow. It gets the job done (I/C piping thru the fender) which is more important IMHO. BUT...I just got the whole sha-bang cosmos package loaded onto my home computer during lunch! Apparently we had an extra seat here at work :) We're still running solidworks '07 so I'm going to have to start over with the models cause I can't import scott's '08 files, and I have never used Floworks so I'll have to teach myself that one. And my vintage '96 15" CRT will need upgrading, I'm used to running dual 19" LCD's at work hehe :) |
Originally Posted by TurboTim
(Post 328219)
And my vintage '96 15" CRT will need upgrading, I'm used to running dual 19" LCD's at work hehe :)
Some of our CAD/graphics guys are using single 30" monitors. They are simply awesome. |
Originally Posted by TurboTim
(Post 328219)
Huh? This is BEGI's thread. BEGI :ne: Absurdflow
Tim @ BEGI :ne: Turbotim. Unless, of course, BEGI hires me, in which case there'd be two Tim's at BEGI ;) The only intake mani I've welded is the one on my car, and I wouldn't consider it absurdflow. It gets the job done (I/C piping thru the fender) which is more important IMHO. You mentioned your Rapid Prototype on the cylinder head and I think ZX-Tex said he wanted to see.. Was curious what kind of psychotic crazy high flowing contraption you might've come up with for intake side :) |
Ill post up some pics here shortly but we are working on some 1.6L short runner manifolds and will be done with the first batch shortly. Orders can be placed via Welcome to Flipside
Gary P.S. didn't mean to steal thread, started one https://www.miataturbo.net/forum/t27887/#post328318 |
Originally Posted by cjernigan
(Post 327995)
Man you have some seriously screwed up eyelids.
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Originally Posted by G2B
(Post 328313)
Ill post up some pics here shortly but we are working on some 1.6L short runner manifolds and will be done with the first batch shortly. Orders can be placed via Welcome to Flipside
Gary P.S. didn't mean to steal thread, started one https://www.miataturbo.net/forum/t27887/#post328318 That design flowed the worst of every design brainiac tested. |
Originally Posted by elesjuan
(Post 328308)
Oh I know you're not Tim @ BEGI.
You mentioned your Rapid Prototype on the cylinder head and I think ZX-Tex said he wanted to see.. Was curious what kind of psychotic crazy high flowing contraption you might've come up with for intake side :) |
Originally Posted by G2B
(Post 328313)
Ill post up some pics here shortly but we are working on some 1.6L short runner manifolds and will be done with the first batch shortly. Orders can be placed via Welcome to Flipside
Gary P.S. didn't mean to steal thread, started one https://www.miataturbo.net/forum/t27887/#post328318 you haven't poste a price for people to order it. |
Originally Posted by TurboTim
(Post 328849)
Gotcha. :bigtu: maybe soon.
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Dyno! (and get our files while you're at it)
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Files are on the way. Got a call from anthony today.
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Originally Posted by TurboTim
(Post 331297)
Dyno! (and get our files while you're at it)
Originally Posted by paul
(Post 331298)
Files are on the way. Got a call from anthony today.
yay, I really want to see artie's before and after. |
I'd scan the printouts but they are kinda useless since before is referenced to engine speed and after is referenced to wheel speed
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Scott, hope you're still playing around with this stuff now that you have your own manifold. Have some ideas:
Originally Posted by Braineack
(Post 327905)
I was playing some more.
I really like the idea of a tapered IM. With what I'm finding, it's providing the best flow into #4. A little too good in this certain case: http://www.boostedmiata.com/projects...d-nostacks.jpg
Originally Posted by Braineack
(Post 327905)
I removed the stacks...seems like they really helped create a larger area to pull airflow from. With the stacks back in place I got flow back into #1. http://www.boostedmiata.com/projects...tacksfloor.jpg
Originally Posted by Braineack
(Post 327905)
so then I thought, why not move the TB inlet back 2" inches to see what difference it had...in the same conditions it flow like the first one...it's almost like the stack of #1 needs to be right at the inlet to work. http://www.boostedmiata.com/projects...ongerinlet.jpg
Originally Posted by Braineack
(Post 327905)
so at this point I thought angling the TB would be the best to retain that lost flow but as to not disturb the airflow to the rear of the manifold. Which seemed to help. http://www.boostedmiata.com/projects...ngledinlet.jpg
Originally Posted by Braineack
(Post 327905)
I was really starting to like this shape, so I went crazy with teh inlet and did the common "teardrop" shape and saw pretty good results. http://www.boostedmiata.com/projects...ngledinlet.jpg What my comments have been building toward are the following suggestions. I'd love to see a sim if you care to continue geeking out with me. Start with something like your 3rd or 4th sim above, and make the following changes: 1. Keep the velocity stacks on the runners, but put them on the outside of the manifold, so the entrances are on the level of the "floor" and there's no turbulent swirl around them. 2. Put a velocity stack on the throttle body flange. I think it would be best to have the flange outside the manifold, as with the runners, to avoid the stagnant, turbulet areas behind the mouth. In general, this should more evenly distribute the intake charge into the volume of the plenum and reduce turbulence. Put some care into how the short-side radius meets the #1 inlet. 3. Play with the angle of the tapered "roof" and throttle body (which as above I think should be parallel) and throttle body fore-aft position, along with short-side radius to #1, until you become a god of Miata intake manifold design. Then we will all :bowdown: Thanks, I'm learning a bunch. This is way better than copying pictures on HondaTech. |
Hey, can SolidFlow provide timed flow demands, simulating the pulsed, alternating flow demands of each cylinder? One of the geeks here said that's pretty important.
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Seems from the simulations that a bigger throttle body would help, right?
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Not on a personal computer. That kind of processing power won't be available for another 10-15 years in a personal computer. If done at high resolution these runs can take you well past 20 hours on a high performance processing center. A transient like that, could take weeks, if the ram is available to handle that information.
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Originally Posted by TravisR
(Post 333481)
Not on a personal computer. That kind of processing power won't be available for another 10-15 years in a personal computer. If done at high resolution these runs can take you well past 20 hours on a high performance processing center. A transient like that, could take weeks, if the ram is available to handle that information.
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A lot of it comes down to what you want to pickup. The general flow patterns are probably about right on. Where the difference shows up comes from the harder questions like how much flow, what temperature, what pressure, and small geometry changes like velocity stacks. This simulation probably should detect something like changing the throttle body orientation, but more than likely couldn't tell the difference between a 1 inch radius and a .125inch radius on a runner stack.
Another weird thing about these simulations is that you can run the same exact simulation twice and get 2 answers that are pretty different. It's like solving the solution for a x^6+x^5+x^4+x^3+x^2+x-5. A polynomial with more the 4 roots is not solvable, and that’s been proven. So the machine has to just basically guess to find the roots, and depending on where it guesses you get different closeness to the true answers. An example would be: If he runs the same problem twice maybe the machine guesses some good guesses on the first run, and comes out pretty close. If the machine on the second run picks some bad guesses then he would get quite a different answer. If he cranks up the resolution there are more guesses all total, and the computer can tell that where there used to be one cell pointing in a reasonable direction there are now 18 cells, and that previous vector makes no sense. Also these simulations very much build like a snowball effect. Its what you would call an N+1 problem. If it takes one of the elements near the throttle body, and the machine just guesses it wrong, everything else behind that cell is very likely to be screwed up. A lot of times a truly good solution involves some advanced techniques; variable meshing density, turbulence setting manipulation, complex boundary conditions. The simplicity of the interface of these programs is a little evil. When you first start using these you think you can solve world hunger. After a few years of using them, you realize if you can’t do an analysis like this by hand, then you probably shouldn’t touch it. I can’t do them by hand, but I’ve had some skilled hands give me a good enlightening on the subjects, and I’ve had around 5 years of experience in using this. Its funny because I started out with, gasp, modeling intake manifolds. My actual parts flowed reasonably close to what the machine predicted in 2003 computer technology. I wasn’t doing anything fancy though, symmetrical designs, and 90* direction change from throttle body to runner. All I was trying to get out of it was if the flow was going to be evenly distributed and it did its job. |
I second TravisR's comments. I don't do this stuff at work, but I'm involved in discussions of the results, and it's been said more than once that if you don't have a pretty good idea what answer you're going to get before hand, the FEA isn't going to be much help.
I remember a project in school where we modeled a simple 2D divergent equation. The point was the limitation of a numerical, rather than analytical, solution. More, smaller steps means more precision, but at the same time, more calculations. Each calculation involves rounding, which affects the input to the next calculation. At some point, the accumulated error of rounding starts diverting the results. So in something as basic as setting up your mesh size, there is actually a peak in quality of results, and a maximum accuracy that can be achieved. Until I can get to a library.... I can speculate about ways the pulsed flow changes the requirement. My main thought is to reinterpret the results with the idea that at some times, most of the flow is going to go into #1, and at other times, most of the flow is going to go into #4. There are probably some good lessons, in that we want to make sure we aren't hosing one of the cylinders by poor flowpath design, as I commented above. I suspect the continuous flow into cylinders #1-3 in the sims is protecting us from the problem of stagnation against the back of the manifold increasing flow into #4. In general, I think that as much as possible, we want the plenum to "look" the same to each cylinder at the time of intake valve opening. That suggests extending the plenum a bit past the #4 runner to provide volume on the trailing side for it to draw from. I'm not sure about the reduced plenum cross section moving toward the back. Edelbrock doesn't seem to do it. It may be that as long as you are above a certain size, being larger or smaller doesn't make much difference. It could be that the only reason to have a taper is to be able to provide good contours on the short side radius between the t/b and the #1 runner. My instinct is that #1 and #4 are where the work needs to go, and if any applicable "best practices" are transferred, #2 and #3 will kind of take care of themselves. The only real way to know is data, of course. Individual cylinder EGTs are one way. I knew an old-school drag racer who used those on his V8. Not a sophisticated guy, but he data logged individual EGTs and jetted each barrel of his dual four-barrel high-rise setup to equalize them. Light years beyond a lot of import drag racers I've seen in operation. For dyno work, you could build a configurable manifold. Play with volume behind the #4 runner, play with some sort of filler material in various places to change contours and flow paths, etc. It might be possible to attempt single-cylinder flow analysis by configuring the runners to reflect the flow conditions at various point in the operating cycle. Say, one cylinder at a time, or have #4 flowing wide open with #1 and #2 closed, and #3 at some reduced flow rate. Maybe tapering the runner to a venturi to control flow rate. Obviously, it won't simulate the possible interference of other runners' pulse events. I don't actually know any of this, except the V-8 guy story. I love making stuff up on the internet. :jerkit: I need a better library. |
Well if anything the intake manifold is much worse in the simulation that brainiac is doing then in real life. That is the good part. Velocity is not your friend, and more then likely he put pressure openings on the runners (28inches of water or something) and atmosphere at the T/B. That means the air is probably flowing through the throttle 4 times faster then it oughta, because only one cylinder fills at a time, and its pulsed flow. With the velocity much much lower, the gas "hugs" the walls much better, and disrupts flow in the cylinders much less, thats because less force=less differential field flow shear going into the runner.
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And I just remembered that Cosworth's 350Z manifold has trumpets in the plenums.
http://www.nyxracing.com/cosworth-ca...2.html?image=0 As does the Duratec manifold: http://www.cosworth.com/popup.php?ur...U2NDUwLmpwZw== Looks like they are working on some different theories. Air moves past the trumpets to fill the plenum, then reverses into them. Avoiding the velocity across the runner openings and resultant potential for uneven flow. Also, countering my suggestion above, it looks like the trumpets may provide additional volume of air accessible to each runner to prevent adjacent cylinders from robbing each other. |
Just looking at that... that company has entirely too much time on their hands.
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I need to figure out how to do this:
and FWIW, simply adding a butterfly valve in the TB inlet significantly changes how everything flow that's I've posted in the past. |
Cosworth also has barrel throttle kits for the Duratec. They're used on the Atlantic motors.
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