VICS Sucks!!!!

[M.Hicks]

From what we all know about flow characteristics, I'm having a hardtime beliving this:
http://www.msprotege.com/forum/attachment.php?attachmentid=46693
out flows this:
http://www.msprotege.com/forum/attachment.php?attachmentid=46692
First it would seem the open butterfly would create a restriction in the intake tract, also it would seem that when the butterfly is open it creates a "long runner" inside the manifold which we all know aids in low-end power. And that @ 5200rpm the butterfly should close, illiminating both the restriction and the long runner, thus utilizing short runner theory(a more direct intake charge). But we know this is not the case, so...
The only sense I can make out of it being the way that it is; is the extra plenum increases total manifold volume allowing greater flow capabilities at higher RPM, but that doesn't explain the susposed restriction of the butterfly right in the middle of the intake tract. The only sense I can make out of it, is Mazda had found some kinda of intake velocity and/or resonance phenomenon. Because upon first impression it looks as if it would be the oppisite...

On that note, does anyone have a diagram of the inner-workings of an FSZE intake manifold?

 

[TurfBurn]

Has nothing to do with flow speeds or volume for air as a "resevoir" has to do with acoustics and the Helmholtz Equations for resonace of a 3 dimensional body... all about inertial charging...

Keep in mind too... everyone gets confused about this... Mazda does NOT design the manifolds for maximum power... they design it for a good curve and also for emissions and fuel efficiency... they have to compromise... that is why aftermarket sheet metal manifolds and other swapped manifolds will often lead to output increases...

 

[M.Hicks]

Sure, thats what I was talking about, Mazda has found some intake velocity and/or resonance phenomenon by opening that chamber, that negates the negitive effects of the butterfly inhibiting air flow in that portion of the runner. The reason I keep refering to it as a phenomenon is because no one can explain exactly whats going on. And I agree with your statement about Mazda not designing the IM for MAX output, however, they did design for improved high RPM power, otherwise they would just be using my probe/mx6 IM or 626 IMs...

no one's using a ZE IM?

 

[TurfBurn]

Look up the Helmholtz equations and that will help you understand what they did... you can actually calculate runner lengths and volumes with it for this sort of thing. But yeah, you are on the right track.

 

[Brian MP5T]

An elliptic partial differential equation given by

<table style="padding-left: 50px;" align="center" cellpadding="0" cellspacing="0" width="100%"> <tbody><tr><td align="left">

</td><td align="right" width="3">(1)</td></tr> </tbody></table>
where

is a scalar function and

is the scalar Laplacian, or

<table style="padding-left: 50px;" align="center" cellpadding="0" cellspacing="0" width="100%"> <tbody><tr><td align="left">

</td><td align="right" width="3">(2)</td></tr> </tbody></table>
where

is a vector function and

is the vector Laplacian (Moon and Spencer 1988, pp. 136-143).

When

, the Helmholtz differential equation reduces to Laplace's equation. When

(i.e., for imaginary

), the equation becomes the space part of the diffusion equation

.

The Helmholtz differential equation can be solved by separation of variables in only 11 coordinate systems, 10 of which (with the exception of confocal paraboloidal coordinates) are particular cases of the confocal ellipsoidal system: Cartesian, confocal ellipsoidal, confocal paraboloidal, conical, cylindrical, elliptic cylindrical, oblate spheroidal, paraboloidal, parabolic cylindrical, prolate spheroidal, and spherical coordinates (Eisenhart 1934). Laplace's equation (the Helmholtz differential equation with

) is separable in the two additional bispherical coordinates and toroidal coordinates.

If Helmholtz's equation is separable in a three-dimensional coordinate system, then Morse and Feshbach (1953, pp. 509-510) show that

<table style="padding-left: 50px;" align="center" cellpadding="0" cellspacing="0" width="100%"> <tbody><tr><td align="left">

</td><td align="right" width="3">(3)</td></tr> </tbody></table>
where

. The Laplacian is therefore of the form

<table style="padding-left: 50px;" align="center" cellpadding="0" cellspacing="0" width="100%"> <tbody><tr><td align="left">

</td><td align="right" width="3">(4)</td></tr> </tbody></table>
which simplifies to

<table style="padding-left: 50px;" align="center" cellpadding="0" cellspacing="0" width="100%"> <tbody><tr><td align="left">

</td><td align="right" width="3">(5)</td></tr> </tbody></table>
Such a coordinate system obeys the Robertson condition, which means that the Stckel determinant is of the form

 

[TurfBurn]

LOL... yeah that'd the one... when I was in college we had to do it a couple of times... I'm at a loss now though on how to execute it completely... a couple hours and I could figure it out... but screw that!

 

[Spooled]

That's what computer simulations are for, haha.

 

[JDM Sam]

Ok bump for a new discussion. So the only difference between the protege intake manifold and the 626 ones are the VICS/VTCS valves? Didn't someone with a 626 manifold dyno more power than with the Protege one? I have a mp3 manifold I want to extrude hone and considered yanking it out but this thread has made me think twice. I'd hate to be a guinea pig and come back and prove what happened here true again, but that other "626" manifold making more hp has me wondering. But again extrude honing it will affect the air flow and thus might negate the negative effects of removing the vics.

Anyone dyno their car with them removed that didn't have boost fluctuations? All this graph shows is the high rpm difference with them open and closed. Obviously it will make more power with the extra plenum open. The low rpm fluctuations b/c of the boost fluctuation varies way too much to draw a conclusion that it killed the low end torque some. I also dont find it a good experiment b/c the valves were left in the manifold even though they are open. A good control/test variable would have been a stock manifold (w/vics) vs. a manifold with both vics removed, assuming VTCS is removed already in both.

Reason being I am looking to increase some top end power which our cars lack.

 

[BlkZoomZoom]

Ok bump for a new discussion. So the only difference between the protege intake manifold and the 626 ones are the VICS/VTCS valves? Didn't someone with a 626 manifold dyno more power than with the Protege one? I have a mp3 manifold I want to extrude hone and considered yanking it out but this thread has made me think twice. I'd hate to be a guinea pig and come back and prove what happened here true again, but that other "626" manifold making more hp has me wondering. But again extrude honing it will affect the air flow and thus might negate the negative effects of removing the vics.

Anyone dyno their car with them removed that didn't have boost fluctuations? All this graph shows is the high rpm difference with them open and closed. Obviously it will make more power with the extra plenum open. The low rpm fluctuations b/c of the boost fluctuation varies way too much to draw a conclusion that it killed the low end torque some. I also dont find it a good experiment b/c the valves were left in the manifold even though they are open. A good control/test variable would have been a stock manifold (w/vics) vs. a manifold with both vics removed, assuming VTCS is removed already in both.

Reason being I am looking to increase some top end power which our cars lack.

I believe only one car was "tested" using the 626 manifold, and that was the people trying to sell it.....

I do not understand why people are still thinking about doing this to their manifolds, Turfburns car lost low end power and lost some top end when the VICS was left open. It is not a good idea, period. Even if you extrude hone the MP3 manifold it still has all the provisions for the VICS system and is still designed with that system in mind. You will end up in the same boat as Turfburn.
Get the 626 manifold, dyno test it, see if there are really gains. Then get it extrude honed and test it again. Thats the only way to really know if it works more efficently than the Protege manifold.

 

[BlkZoomZoom]

From what we all know about flow characteristics, I'm having a hardtime beliving this:
http://www.msprotege.com/forum/attachment.php?attachmentid=46693
out flows this:
http://www.msprotege.com/forum/attachment.php?attachmentid=46692
First it would seem the open butterfly would create a restriction in the intake tract, also it would seem that when the butterfly is open it creates a "long runner" inside the manifold which we all know aids in low-end power. And that @ 5200rpm the butterfly should close, illiminating both the restriction and the long runner, thus utilizing short runner theory(a more direct intake charge). But we know this is not the case, so...
The only sense I can make out of it being the way that it is; is the extra plenum increases total manifold volume allowing greater flow capabilities at higher RPM, but that doesn't explain the susposed restriction of the butterfly right in the middle of the intake tract. The only sense I can make out of it, is Mazda had found some kinda of intake velocity and/or resonance phenomenon. Because upon first impression it looks as if it would be the oppisite...

On that note, does anyone have a diagram of the inner-workings of an FSZE intake manifold?

Your diagram is way off. When the VICS opens the butterflies don't even come close to blocking any flow. The runners are divided until they reach a straight path.

 

[TurfBurn]

I believe only one car was "tested" using the 626 manifold, and that was the people trying to sell it.....

I do not understand why people are still thinking about doing this to their manifolds, Turfburns car lost low end power and lost some top end when the VICS was left open. It is not a good idea, period. Even if you extrude hone the MP3 manifold it still has all the provisions for the VICS system and is still designed with that system in mind. You will end up in the same boat as Turfburn.
Get the 626 manifold, dyno test it, see if there are really gains. Then get it extrude honed and test it again. Thats the only way to really know if it works more efficently than the Protege manifold.

didn't lose any low end that was visible on the graph when left open... and DEFINITELY didn't lose any top end with VICS open.

 

[BlkZoomZoom]

The graph that is higher that I posted... that is with them open from start to finish... you can see where on the low end it's a tiny tiny bit lower... but not much.

?

 

[TurfBurn]

Here is the 8.5/9 psi comparison.. keep in mind that every run I did had the VICS open at low rpm's... there is nothing I did that would provide a comparision between vics open or closed below 4500 rpm's.... all my runs were with vics open either from start to finish, or vics open from start to 4500 rpm's and then closed from 4500 rpms to finish, which is what this red curve shows... The fact it is a little higher for a bit can easily be attributed to a variance in boost rather than any affect of the manifold. Don't know that for sure, but it is very much possible... it is however, quite obvious that from 5200 up having VICS butterflies open is a significant improvement.

 

[TurfBurn]

Quote:
<TABLE cellSpacing=0 cellPadding=6 width="100%" border=0><TBODY><TR><TD class=alt2 style="BORDER-RIGHT: 1px inset; BORDER-TOP: 1px inset; BORDER-LEFT: 1px inset; BORDER-BOTTOM: 1px inset">Originally Posted by TurfBurn
The graph that is higher that I posted... that is with them open from start to finish... you can see where on the low end it's a tiny tiny bit lower... but not much.
</TD></TR></TBODY></TABLE>


?

The butterflies were open in all cases though from beginning to 4500 rpm's... I never ran with butterflies closed at the beginning.... So we don't have any comparison there... I'll go find that post to see what point i was trying to make.

 

[TurfBurn]

Looks like the only thing I can find is how it is every so slightly lower between 4.5 and 5.25... but again that could be boost related... so I don't know as it is justification to prove anything.

 

[BlkZoomZoom]

So then why is your point in this thread that you can lose some low end to stop wheelspin if you leave the VICS open?

 

[BlkZoomZoom]

http://www.msprotege.com/forum/showpost.php?p=1848058&postcount=45


I think I said this before, too much mis-information and theory going on in this thread. Not enough facts.

 

[TurfBurn]

So then why is your point in this thread that you can lose some low end to stop wheelspin if you leave the VICS open?

Because everybody says or claims that we will lose torque in the low end with them left open.... There is no dyno to prove it, but that is still the prevailing logic in the community... and according to Kooldino, Terry once proved that to be the case.

 

[TurfBurn]

http://www.msprotege.com/forum/showpost.php?p=1848058&postcount=45


I think I said this before, too much mis-information and theory going on in this thread. Not enough facts.

The main cause of the problem is the simple fact that saying the VICS is active gets interpreted differently by different people.. I did the same thing as well.. VICS active is the runners closed for low end power... everyone assumes/assumed that VICS was for improving top end... it's not.. it's for improving bottom end... and saying "VICS is active" means the butterflies are closed until around 5200 rpm's. But that isn't well understood or translated.

Again though.. as far as the "losing low end torque" that is based off the general agreement amonst everyone that having the runners open on the low end will cause a loss.. we don't have any dyno's to show it... but I would assume mazda wouldn't have added the complexity and the cost of the system if it didn't do something for the low end... but as I said... there is nothing in MY graphs that shows it definitively.. so saying that I lost low end power is false because nothing on my graphs can prove it...

 

[TurfBurn]

I added edits to the early posts to make it more clear and to correct impressions of misinformation overall..