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I have to disagree (talking strictly FI applications here). I don't think the gains are necessarily what Kinetix advertises, but I think they are on par with what other plenum upgrades provide, maybe even slightly better. Check my dyno numbers. I have not seen anyone with similar mods (different plenum) hitting anywhere close to my numbers with a Vortech and stock bottom end.

I've always said if you are only concerned with the performance aspect, go with the Crawford plenum. It'll give you similiar power gains for a lot less cash... a great proven product. If you want the power gains AND want something really nice for shows, invest in the SSV.
 

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I only read the first post in the link provided and it sounds like he didn't tune. I have not done any tuning, but based on what I've been reading here and elsewhere, you MUST find a way (reflash, piggy-back, etc) to tune the car for any of the breathing mods to be effective. I believe it WILL make a difference (albiet, a small one) for NA IF you tune it.
 

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I think Zivman is out to prove kinetix is crap.. unfortunately no matter what stance on any issue you take, there is evidence to prove a point.
 

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Discussion Starter · #8 ·
I think Zivman is out to prove kinetix is crap.. unfortunately no matter what stance on any issue you take, there is evidence to prove a point.

I am out to prove no point. I merely linked some info about the SSV plenum. Until someone can provide info beyond that it is great because it is shiny, my personal opinion is that is a garbage piece.
 

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Discussion Starter · #9 ·

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I am out to prove no point. I merely linked some info about the SSV plenum. Until someone can provide info beyond that it is great because it is shiny, my personal opinion is that is a garbage piece.
to each their own :cheers:
 

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I am out to prove no point. I merely linked some info about the SSV plenum. Until someone can provide info beyond that it is great because it is shiny, my personal opinion is that is a garbage piece.
Again, I state... check my sig. As far as I know, no one with a Vortech with a stock bottom end and similar mods as me (but different plenum) is anywhere near my HP/TQ numbers. Get over it, it works at least as well as the other plenums out there.

I don't think it's crap, I just think it's WAY overpriced.
I agree... that's why I've always said if you just want the performance, go for one of the other plenum options. If you want the performance plus a very bling-bling showy piece for show car stuff, get the SSV.



Ooooooorrrrrrr.... you could just wait for the uber-sweet item Doug over at Crawford Z Car is currently working on. :drool: Unfortunately, I am sworn to secrecy and can say no more about it right now. :biggrin:
 

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I think a good way to settle this isn't with dyno runs, but with air flow rates. I don't know what they are called, but there is a machine that you can hook an intake ONLY up to (ie: remove it from the engine and place it in/on the machine) and it will give you cfm's (cubic feet per minute) through the intake manifold. It would be interesting to see the flow rates between a stock plenum, the Kinetix SSV, and some other popular 3rd party plenum. I was lucky enough to tour a custom shop near Minneapolis that is known for tuning and customizing Corvette engines, and they had one of these flow machines. It was pretty interesting how they used it to tweak their intake designs.
 

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I think it is time to take a little look at physics and plenums. The stock, sloped plenum was not created by accident nor by need to fit it under the hood. There was actually quite a bit of thought that went into this plenum. The sloped plenum is designed to keep air pressure equal along the entire length of the unit. The rule that applies here is PV=nRT. P is pressure, V is volume, n is the number of moles of gas (air), R is the universal gas constant and T is temp. Rearranged, the equation is
P=nRT/V and essentialy says that if the volume decreases proportionally to a decreasing number of moles of air, then the pressure in the container will remain constant.

As air initially enters the rear of the plenum there is a large quantity of air in a tall chamber. As the air flows forward in the plenum, some of the air leaves the plenum by moving into the first intake runner and cylinder. The remaining air continues to flow forward in the sloping plenum. There are a decreasing number of moles of air as the flow continues to move forward past each intake runner. The plenum is sloped to reduce volume toward the front of the unit. This keeps the pressure equal throughout the length of the plenum and thereby provide equal air flow to each cylinder.

A plenum with an equal volume front to rear will have decreasing pressure from the rear to the front leaving each forward cylinder more air starved than the cylinder behind it.
 

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that is good physics, however can you explain why most of the engine failures have been from detonation in the forward 2 cylinders?
 

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Nice to see a informative discussion developing...too bad the thread title does not reflect it's true content.
 

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The physics are correct in your thinking. However I will argue that the cylinders are going to suck as much air as they can, and limiting the front 2 cylinders is not a good thing.
 

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Toykilla,

The cyclinders will intake a volume equal to their displacement, but they can only intake from the supply that is available. There is a given quantity of air in the plenum. Think in terms of moles of a gas, in this case that gas is air. If we increase plenum volume, the pressure drops and the moles of gas expand to fill the volume. For ease of computation lets assume that the cylinder displaces 1 liter. If we have 100 moles of air in a 1 liter volume of the plenum above the cylinder intake, then that cylinder will intake 100 moles of air. If we increase the volume of the plenum above that cylinder to 2 liters we get a pressure drop and the 100 moles of air expands to fill the 2 liter volume. The cylinder only displaces 1 liter and now that 1 liter volume only holds 50 moles of air. By sloping the plenum we get to keep consistant pressure rear to front and a more even distribution of air to all cylinders.

A good analogy is a person exercising at sea level and then at a high altitude . There is greater atmopheric pressure at sea level than at high altitudes. Regardless of which elevation you are at your lungs will pull in the same volume each time you breath, but because of the higher atmopsheric pressure at sea level there are more moles of oxygen per given volume. This is the reason people fatigue earlier at higher elevations
 

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Toykilla,

The cyclinders will intake a volume equal to their displacement, but they can only intake from the supply that is available. There is a given quantity of air in the plenum. Think in terms of moles of a gas, in this case that gas is air. If we increase plenum volume, the pressure drops and the moles of gas expand to fill the volume. For ease of computation lets assume that the cylinder displaces 1 liter. If we have 100 moles of air in a 1 liter volume of the plenum above the cylinder intake, then that cylinder will intake 100 moles of air. If we increase the volume of the plenum above that cylinder to 2 liters we get a pressure drop and the 100 moles of air expands to fill the 2 liter volume. The cylinder only displaces 1 liter and now that 1 liter volume only holds 50 moles of air. By sloping the plenum we get to keep consistant pressure rear to front and a more even distribution of air to all cylinders.

A good analogy is a person exercising at sea level and then at a high altitude . There is greater atmopheric pressure at sea level than at high altitudes. Regardless of which elevation you are at your lungs will pull in the same volume each time you breath, but because of the higher atmopsheric pressure at sea level there are more moles of oxygen per given volume. This is the reason people fatigue earlier at higher elevations
This is all true if we assume that air behaves as a perfect gas, inlet pressure and temperatures are constant, and there are no abdiatic processes in effect. Also we must disregard some degree of fluid dynamics. Oh and I almost forgot accoustical effects.

Carry On
Ronin Z
 

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I understand the reasoning for the slope, and as ronin said in a perfect environment it would probably work. However it is hard to argue with facts, and I remember a while back reading some air pressure tests showing the front cylinders being starved for air. The theory of the slope is good but in practice it does not seem to work as well as expected. That being said, I can't remember seeing any similar tests done on aftermarket plenums.. I really need to dig up that post.
 
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