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Hello, thanks for the information.
I love the tutorials and I plan to use them.

I am clear that the first thing I will do is dismantle clean and check what I have in the intake and exhaust.

Maybe buy a butterfly and an admission of the St200 that I sell for € 130 (if my wife lets me buy it ....)

But looking for information about the intake pipes, I read this post last night:

Teoría: Largo del conducto de admisión - Suzuki Swift Argentina

And that led me to others and I realized that I'm not right to understand how the admission in two stages of this car.

I make the mistake of thinking about how monocylinder motors work where a free admission and a free escape is where they have the most power.

But from what I have seen there are complicated calculations of harmonic frequencies that are used in competicon but that the manufacturers for problems of space do not usually respect.

If this is done well you get a supercharging and an increase in power, therefore it is more important that the intake manifolds have the correct lengths than a wide diameter.
*
So I begin to understand when a cylinder breathes (in low) needs to have that flow of air prepared in the fine and long duct as fine as the valves allow and so long need the capacity of the cylinder. so it does not bother the breathing of other cylinders

All cylinders breathing create a frequency

if we use the first or second harmonic of that frequency we gain overpressure.

(This is not exact but in the next few days I will learn more)

The high-performance racing cars are optimized at the maximum RPM so it is the camshaft that commands.

In high-performance street cars, variable camshafts are used and therefore a variable intake, which means variable acoustic intake, by using this resonance by adapting length to engine revolutions.

Our engine has 170hp at 6250 rpm
And its torque is 162lp or 220Nm at 4250 rpm

So the long tubes of our intake would have to be calculated to work resonating at 3500 - 4250rpm?
And our short tubes to reach that resonance at 6250rpm?

I would like to see the curve power to see if you can see where those top points are to see if someone has the original factory car and we can see the graph?

Does anyone have the original graph of power and torque?

I do not think that the manufacturer optimized the distances of our intake manifolds, they are very beautiful and they fit the hollow of the engine very well to be perfect

I think that they have approached those measures respecting the thicknesses in their formulas.

As the length measurement is from the valve to the throttle butterfly maybe we could gain some length, shorten it I see it more difficult ... or in the case that our tubes do not have the perfect length measurement one could make a collector artisan admission

With the exhaust manifolds I see that something similar happens but I think the important thing is the total length and the section.

If it is difficult but it is entertaining and we do not lose anything to do calculations, it is free.
 

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Hello again I have found a final degree project that has clarified a bit what some call RAM effect or the resonance of food or whatever it is called
https://www.iit.comillas.edu/pfc/resumenes/55dc9bdac2a77.pdf

this is a small summary of the theory in the absence of a program that calculates it and the information of our necessary engine
https://docs.google.com/document/d/1Gnv2LjBM4YRCr-W-uSJyNdXl7wjRF0B_e9l8LPBq6EE/edit?usp=sharing



The calculator on this page does not work
https://www.engr.colostate.edu/~allan/fluids/page7/page7.html


Already with this page I leave it for today I will explode my head

https://jasf1961.wordpress.com/category/calculo-del-motor-engine-design/
 

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Discussion Starter #23 (Edited)
Now your going down the same rabbit hole many of us have gone down before. Your train of thought is exactly why this thread came into existence in the first place, so that I could document the actual dimensions of our components in order to refer back to them for custom intake manifold designs. There are a lot of variables that go into the factory design of these things, and the engineers make their own assumptions about what the best compromises are between competing factors. Those compromises are intended to make the most average drivers happy at a minimum cost. Enthusiasts may have different priorities than those engineers did.
Its easy to spend a lot of time reading about resonance tuning theory, but the end result of all that reading usually leads to the conclusion that the SVT manifold is probably the best compromise available on the market.
Speaking just for myself only, I'm skeptical that investing a lot of time worrying about resonance tuning is worthwhile, as it really only matters at very specific RPM's, and the entire rest of the band it has little or no effect. Because of that, If I ever get around to building a custom intake manifold, I wont be worried about resonance calculations.

There are some dyno plot sheets here:
https://www.newcougar.org/forums/2-5l-duratec-performance/89952-2-5l-dyno-plot-sheets-post-yours-here.html
 

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Hello, if you are right again all the theoretical work will have to be accompanied with practical measurements to see the effect of all the parameters that we can not calculate.

But I have the theory that the measures of length of the 170hp and the 205hp, of the st220 are the same, but i will take measures of length and capacity of the plenum another moment.
On the outside it looks the same:

https://www.newcougar.org/forums/2-5l-duratec-performance/197267-2-5l-hood-clearance.html

I explain my theory with a power graph:



In the graph we can see that the torque curve is not one, there are two curves:
One of low and another of high being:
Point 1 the maximum torque at low.
Point 3 the maximum torque at high.
And point 2 on the 3500 rpm when the second body of the intake manifold enters the short tubes, at the moment that sends the IACV, which by the way tomorrow, I think to check and clean it in my car.

I think that the point "supercharging effect" or resonance or whatever we want to call, that point where the engine breathes best, are the points 1 and 3 and maybe if we lengthen or shorten the intake manifolds we vary positions / rpm of the points 1 and 3.

And I'm almost sure that the graph of the ST200, the points 1 and 3 althougth they have more value are in the same RPM.
 

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you know, to back up the data you just compiled, you could probably actually calculate this, ish. RPM and approximate valve lift points in the revolution, coupled to the speed of sound through air and the length of the tube. find the RPM point at which the runner length is such that that pulse coming from the intake valve has exactly the time it needs to go all the way to the plenum, bounce off, and then come back to the intake valve when it's open again, and I'll bet you you'll get something similar to the points you just found.

that's the basic theory behind intake (and exhaust!) scavenging, so it should line up (ish.), although I say ish because flow is something very, well, fluid, and is affected by a bagilion factors, which might slightly sway the results. but i'll bet you it's an okay approximation.
 

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Discussion Starter #26
Yes, the runner lengths in the SVT upper manifold are the same as the basic manifold. Its the same casting, but the SVT manifold was honed out internally. (I hope "Honed" translates well to spanish for you)
Youre on the right track in your understanding of things, but dont forget the intake is only part of the equation. You also have cams, exhaust, fuel injectors, head design, and ECU tuning as contributing factors. Those inflection points arent where they are by chance, they are there because the engineers put them there.
 

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I do not want anyone to get confused with my quick translations from Spanish to English.

I do not see myself able to do those calculations.
But I do want to understand them.
I think if I'm right:
By shortening or lengthening those tubes, we would go up or down in rpm at point 1 and 3 and thus make point 2 go up or down.

But it is necessary?
Those who have many years of the car, and know it very well on the road, if you could modify the torque curve in its form, (not in power that we would all like) where would you place points 1 and 3: in the same place? , more together ?, more to the right?

Thank you.
 

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Hello, precisely to repair the IMRC I will disassemble the upper intake manifold and clean it.

"Honed" en español tiene muchos significados, como mejorado o afilado.
Pero no se si es:
"pulido" o "bruñido"?

Pulido:


Bruñido:



Thank you
 

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Discussion Starter #29
Yes, that is cylinder honing.
Intake manifold are honed using an abrasive putty.
[video]https://video.search.yahoo.com/yhs/search?fr=yhs-btf-002&hsimp=yhs-002&hspart=btf&p=extrude+honing+video#id=2&vid=eb118be86c4ade4d5fbc4a2db6d26ce0&action=click[/video]
 

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Hello
Thank you for the clarification, to see how dirty they are when I remove it, but first I will repair the IACV and prove it works.

I am very happy with the car, I was glad to see that I had the IACV transistor broken, repairing the transistor and cleaning the intake manifold, I know I am going to earn a lot of CV, (It is what I have to buy the car already broken and never having driven one in good condition)
Thank you
 

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Discussion Starter #31 (Edited)
Because this is a convenient place for me to save this information:
I measured the volume of my 3.0 UIM I have sitting in the corner and the SVT UIM I'm prepping to put on the yellow car.
I believe its from an 04-05 Taurus - 5100 ml
SVT UIM - 3950 ml
Will be measuring the normal 2.5 in the near future when I get the SVT manifold installed.

Now if only I could get Andy to measure his, we would know exactly how much extra metal came out of it...:poke:
 

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Still - no matter how much optimization you do, you're still working with only 2.5 liters of naturally-aspirated displacement. With relatively low compression. That juice isn't worth the squeeze when you're fighting for fractions of a horsepower point.

Work on increasing your grip for the REAL dividends.

The thing I enjoyed most about my 2.5 was its responsiveness. The SVT throttle body, paired with the lightened flywheel, gave such terrific throttle response.
How much less weight?

Stainless braided brake lines and upgraded pads gave terrific braking response.

Any known store? Where can I find them?



PRT billet front subframe bushings and energy suspension rear trailing arm bushings, along with a rear strut tower brace and larger rear sway bar and proper sticky tires, gave it terrific steering response and turn-in.

Any known store? Where can I find them?


Even though the 2.5 was gutless - even after all the intake and exhaust modifications I made to it - the car STOPPED when you braked, it REVVED when you throttled it, and it TURNED IN when you moved the tiller. No lag, no delay, instant gratification.

Thanks for the information, as always grateful
 

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The Fidanza aluminum flywheel weighs 9 pounds, IIRC. The stock Cougar flywheel weighs about 22 pounds.

The brake lines I have are Earl's brand. I bought them second-hand, but there should be available stock out there somewhere.

PRT parts are sold through prtautosport.com - he's doing another run of the subframe bushings, so they aren't on the online catalog right now. Email Josh to see about getting some if you don't see them there.
 

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The Fidanza aluminum flywheel weighs 9 pounds, IIRC. The stock Cougar flywheel weighs about 22 pounds.

Is there a loss of inertia or on slopes or in urban traffic with the aluminum steering wheel?

Thanks
 

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Is there a loss of inertia or on slopes or in urban traffic with the aluminum steering wheel?
Thanks
The main drawback is in low-speed driving, like moving slowly through a parking lot. On/off throttle transitions are rather dramatic, so there is definitely more lash, having so much less kinetic energy to smooth out the drivetrain. It also robs a little torque on the top end compared to the heavy original flywheel which will carry that kinetic energy with it.

But the responsiveness of the throttle is astonishing when you take away all that rotational mass in there. The entire car seems lighter and more responsive.
 

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Discussion Starter #36
MSDS header volumes:
Front - 1500 ml
Rear - 1100 ml
 
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