Mohsin

informative thread, count me in for a velocity intake

The Birdman

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by adirondackR &raquo;</TD></TR><TR><TD CLASS="quote">yes it is - to my understanding see more
http://www.intrinsicperformance.com/pr_vstack.html

ALLMOTOR18 looks much different tho *shrug*</TD></TR></TABLE>

Yes, it does seem a bit different than the pic at the top of the page posted by B19coupe, not ALLMOTOR18 though, the pic he posted was of the ebay stack...

This pic looks like the length of the taper is smaller. Any ideas Bryan? It sounds like that is more towards what you were saying was optimal.


Modified by jd3jdm at 4:22 PM 12/4/2005

b19coupe

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by adirondackR &raquo;</TD></TR><TR><TD CLASS="quote">ALLMOTOR18 looks much different tho *shrug*</TD></TR></TABLE>
That is the intake stack that got it's butt kicked by the Prototype piece.

6SPD_EK

iTrader: (2)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">
That is the intake stack that got it's butt kicked by the Prototype piece.</TD></TR></TABLE>

makes sense... me for not getting that the 1st time I thought that one looked kinda cheap

I will post some pics when i get mine but it will be a 'lil while - its being sent directly out to be attached to a custom intake to fit an k20 RBC (euro accord type r/'06 si) intake manifold

Supahr_Ed

Sorry but im not too fimilar with all this fluid movement lingo BUT on a similar note...does this Turbonetics velocity stack just as good as the Prototype? I notice that the turbonetics does seem to go about 180 degree around on the Lip but has a opening snout similar to config. 5, where the Prototype looks like config. 3. Do you believe the Turbonetics will perform just as good b/c of the rounded lip or suffer because of its funnel design....(hard to tell from pic)

I have heard great things from the Prototype before and now from this thread...just looking for other similar options..


on the great scientific analogies





Modified by Supah_Eg6 at 4:06 AM 12/6/2005

BigMoose

Nice work!

If you can, model a sheet of window screen over the bellmouth, folks will be very interested in the results you get...

DX4U2NV

any graphs of Allmotor18's motor with no velocity stack at all?

StyleTEG

That is weird that the prototype racing stack seemed to amplify the "AEM Hump" compaired to the ebay one?

You say the intake lengths were the exact same?

b19coupe

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StyleTEG &raquo;</TD></TR><TR><TD CLASS="quote">That is weird that the prototype racing stack seemed to amplify the "AEM Hump" compaired to the ebay one?
You say the intake lengths were the exact same?</TD></TR></TABLE>
The AEM hump is at 4,500, notice that on Jason's graph that the hump is closer to 6,100 or so. The intake lengths were within an inch or two of each other. Notice that the peaks and valleys in the torque curve mirror each other fairly closely.

On a side note, the A/F was not tuned for the Prototype intake at all. There are probably a couple of HP here and there if the A/F had been tuned for the Prototype intake too.

ALLMOTOR18

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DX4U2NV &raquo;</TD></TR><TR><TD CLASS="quote">any graphs of Allmotor18's motor with no velocity stack at all?</TD></TR></TABLE>

The was no improvement from a filter to my generic velocity stack...

cptengineer

cool

alfaaay

really sweet discussion going on I've done a little fluids work (studying ME right now), so it's great to see this stuff applied. Just curious, but are you able to pull a velocity profile from FloWorks? I know it's got a way of modeling velocity distribution, but I've never seen it spit out anything that made total sense.

BTW, any idea how these findings might change, if at all, if applied to ITB's, or even velocity stacks at the end of intake runners?

PM'd you too...

visi0n

BryanPendleton,
what modeling software are you using? i would like to purchase that type of software or download it. been looking but without knowing exactly what to look for i've been lost.

BryanPendleton

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by alfaaay &raquo;</TD></TR><TR><TD CLASS="quote">really sweet discussion going on I've done a little fluids work (studying ME right now), so it's great to see this stuff applied. Just curious, but are you able to pull a velocity profile from FloWorks? I know it's got a way of modeling velocity distribution, but I've never seen it spit out anything that made total sense.

BTW, any idea how these findings might change, if at all, if applied to ITB's, or even velocity stacks at the end of intake runners?

PM'd you too...</TD></TR></TABLE>

You can graph velocity contour maps. I will try and post up some various graphs. But keep in mind that with the length of intake pipe I have modeled, there is not sufficient length for the velocity profile to stabilize from the entrance flow effects. Meaning the velocity profile is stilll change as the air moves down the intake. I am simply guessing, but it may take a few more inches for that to occurs, and it also V.stack configuration dependant. For example the config for velocity profile stabilizes much more quickly, thus the lower max velocity shown on pg1.

I am going to further my analysis by studying the effects of filter vs. no filter, because I now have reason to believe there may be some effects there that drive a different configuration depending on whether your use a filter or not. Reason being as the cone filter is caped on the end, force the pressure gradient to the radial diameter of the filter. You will not have this effect (or at least not a much) without a filter. Theorizing here, but a config 4 design may prove more beneficial if not running a filter.

I have ordered a RF-1048 K&N filter. When it arrives, probalby the end of this week I will model it and rerun some studies, as I will ultimately try and optimize a v.stack for this filter and as mentioned above determine if the filter drives the v.stack configuration any.

Oh and as for ITBs, this type of analysis is probably not representative for valid, simply because of the dynamics and cyclic nature of the fluid flow. The entrance into the intake is far different animal than the entrance into a indivdual combustion chamber, especially that close.

BryanPendleton

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by visi0n &raquo;</TD></TR><TR><TD CLASS="quote">BryanPendleton,
what modeling software are you using? i would like to purchase that type of software or download it. been looking but without knowing exactly what to look for i've been lost.</TD></TR></TABLE>

SolidWorks Modeling package with Cosmos FloWork Package. I am sure student version are available pretty cheap, and presumably have full capacity of professional liscense version.

Adam.

Bryan,

To your best opinion is there any benefit to running the j's style intake tubing rather than a straight pipe?

EDIT: Pictured here:

BryanPendleton

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DarkKnight1 &raquo;</TD></TR><TR><TD CLASS="quote">Bryan,

To your best opinion is there any benefit to running the j's style intake tubing rather than a straight pipe?</TD></TR></TABLE>

I really don't have a "formulated opinion" on the J's intake at this time. Per someones comments on pg1 about improves midrange, but loss of high end, I theorized one possilble explanation. If indead, J's improve midrange with a loss of highend, when compared to a straight pipe intake, then you have your answer, you just need to determine what is more important for you application. highend or midrange? This is based on 1 mans experience though, and may not be representative of the whole.

Adam.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BryanPendleton &raquo;</TD></TR><TR><TD CLASS="quote">

I really don't have a "formulated opinion" on the J's intake at this time. Per someones comments on pg1 about improves midrange, but loss of high end, I theorized one possilble explanation. If indead, J's improve midrange with a loss of highend, when compared to a straight pipe intake, then you have your answer, you just need to determine what is more important for you application. highend or midrange? This is based on 1 mans experience though, and may not be representative of the whole.</TD></TR></TABLE>

Yea, I guess that's why I posed the question in the first place. You seem to be the first person who seems knowledgeable in the area of flow mechanics and thus I wanted to garner your opinion, or at least your best guess at it.

alfaaay

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DarkKnight1 &raquo;</TD></TR><TR><TD CLASS="quote">Bryan,

To your best opinion is there any benefit to running the j's style intake tubing rather than a straight pipe?

</TD></TR></TABLE>

I know you directed this question towards Bryan, but something you might want to consider is that the J's is supposed to give really good throttle response, and I think that's why some people might choose it over other intakes. The design itself doesn't seem to be that great of an idea in regards to power. Typically a taper like the one seen on the J's will increase intake velocity, but as mentioned, the velocity profile will kinda suck (flow possibly has much less chance to become fully developed?), meaning a lower mass flow rate.

M@

I would lean towards config 4 or 5 for running w/ a filter.

Config 2 or 3 for running w/o filter.

For those that don't understand flow as well as others. The problem w/ entrance loss is delamination of the flow from the walls of the pipe. If the flow delaminates then it can constrict the opening. In a pipe w/ water and no transition w/ a 90* bend, that constriction can be 30-40%.

I guess that's all been said.

Here I made this neat little drawing w/ paint. lol


If this was a stand alone pipe w/ no wall, then you would have air on the outside of the pipe going to the entrance even if it is to the right of the actual intake. So you would have even more constriction as the flow tries to bend around the 180*.

I'm sure there are differences with air and water, also an engine can benefit from resonance form the intake. This is a start of a long lesson that I'm not qualified to finish, or even start for that matter.

BryanPendleton

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by M@ &raquo;</TD></TR><TR><TD CLASS="quote">I would lean towards config 4 or 5 for running w/ a filter.

Config 2 or 3 for running w/o filter.</TD></TR></TABLE>

My own findings are not conclusive at this point, but I am finding my results show just the opposite. Here is my explanation as to why I believe I am seeing these results. I cone filter has a "wall" infront of the V.stack inlet, with the distance dependant on filter geometry. This means fluid flow must come from the radius or the fringes of the velocity stack. A large full radius on the entrance to the v.stack allows the pressure gradient to reach further out radially, where as the "funnel" type configuration (such as 4&5) v.stack allow the pressure gradient to project out the inlet more. Keeping in mind that the pressure gradient is driving the fluid flow, if not filter is used then the "funnel-like" configuration seems to allow more flow, where with a filter the full radius v.stack allows the pressure gradient to act on the fringes of the inlet, which is where the air is coming from (ie through the filter element). I am still running some tests to fully convince myself of this, but seems to be the case at this point.

I think the thing people need to keep in mind is that regardless of v.stack geometry, you will have a significant advantage over straight pipe entrance, as you will not get the boundary layer seperation that M@ sketch shows, which effectively acts like a restrictor plate.

M@

Props for using the scientific method.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BryanPendleton &raquo;</TD></TR><TR><TD CLASS="quote">

...cone filter has a "wall" infront of the V.stack inlet, with the distance dependant on filter geometry. This means fluid flow must come from the radius or the fringes of the velocity stack...</TD></TR></TABLE>

I see what you are saying, I just don't think that its fair to say the air is coming from the "fringes". If you look at a "cone" filter like any that have been posted there is a good amount of area away from the fringe. It should be safe to say that most of the area is moving the air threw it the same. If you look at the gradient on stack 4 you posted the air outside of the intake is all the same pressure. Thats not the reason I said 4 and 5 though. I was thinking that most of the air would be entering the filter at a 90* to the pipe. So a 90* stack would be better. Thats just what I was thinking though. It could be one of the other vairables that cause the difference, either way you testing will get the bottom of it.

Keep up the good work.

nuclearhappines

why not put a velocity stack on the end of a j's racing intake ?

can you even model that ?
has anyone dynoed such a frankenstein intake ?

xtrafastcivic

joe at prototype racing doesnt like to answer emails...

Adam.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by M@ &raquo;</TD></TR><TR><TD CLASS="quote">Props for using the scientific method.

I see what you are saying, I just don't think that its fair to say the air is coming from the "fringes". If you look at a "cone" filter like any that have been posted there is a good amount of area away from the fringe. It should be safe to say that most of the area is moving the air threw it the same. If you look at the gradient on stack 4 you posted the air outside of the intake is all the same pressure. Thats not the reason I said 4 and 5 though. I was thinking that most of the air would be entering the filter at a 90* to the pipe. So a 90* stack would be better. Thats just what I was thinking though. It could be one of the other vairables that cause the difference, either way you testing will get the bottom of it.

Keep up the good work.</TD></TR></TABLE>

I'm guessing the only real way to tell would be using his flow modeling program.