TB vs TB Spacer?

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Would like to get a little more out of my '90 model 3.9 Dak. and the most common suggestion that I see on the WEB is change out the TB to either an improved V6 or a V8. When I start Shopping
around (EBay etc.) I see a lot of TB Spacers but no TBs. They are not the same thing are they? What difference?
Thanks
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No, they are not the same thing. The TB or throttle body controls the amount of air entering the intake manifold. A TB spacer fits between the throttle body and the manifold with the idea of smoothing out the airflow into the intake for better fuel atomization and allowing more air to get into the cylinders.
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"Bob" < snipped-for-privacy@sbcglobal.net> wrote in message
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Yup.
Perhaps, but more likely its to add length to the intake tract in an effort to get more low end torque. Not that it always works thta way. Smoothing air flow by adding a second mating point seems a bit odd. Better idea is to use something that will produce laminar air flow, which could be added with the spacer, but usually is not.

Atomization, perhaps yes. More air into the cylinders? Nope. As you just said, the TB regulates that, not the spacer.
Ultimately, the spacer is a debatable add on, but a cheap experiment.
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Max

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airflow
effort
air
use
the
While the TB regulates air flow, that flow is ultimately limited by the efficiency of the intake system as well. The spacer as you said, increases the length which should, but not always, increase air speed and reduce turbulence which should get more air into the cylinders. Why do you think that they are said to increase lower end torque, debatable or not?

Agreed.
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The op stated he had a '90 3.9l engine. IIRC this motor used the barrel shaped intake manifold. If you take this manifold off and take the bottom plate off, you'll see that as the air comes thru the t/b it enters a chamber roughly the size of a gallon milk jug. The intake runners start at the bottom of this cavern and go up and over the top of the manifold to the opposite bank of cyls. I fail to see how adding a half inch spacer at the top of this cavern would make didly squat difference in the airflow thru the manifold. I could see how a spacer could work on a single or double plane manifold but this???? Take a look at hughesengines.com and read how they modify the manifold for higher flow. Notice they don't sell spacers but they do sell other performance enhancing items. This tells me they probably know more about these engines than J.C. Whitney.
Denny
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Bingo.
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Max

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Plane??? WTF are you talking about? This is supposed to be about a spacer! Now your confusing the issue with planes, not just a single plane, but your also talking about a couple of them. Looking back at your post, I see you are also talking about joggers, and milk jugs, caverns and being over the top. I also see you mentioned taking a plate off. Now that is something I'm sure you have expertise in, taking a dinner plate off the table. I'm just throughly confused by your explanation, do you think you could clear it up a bit?
I'm glad somebody is paying attention and trying to correct some of the misinformation that has been tossed out here recently, keep up the good work. <GBMFG>
Roy

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Well hot damm!!!!! Ole Pudge of the East looks like he's trying to think again. Stand up there Pudge, it'll go better for ya..

I told you to stand up before you try thinking. Or maybe you're just thinking bout another pack of Twinkys.

I'll leave that up to 'bone. He has more time than I do.

Great Brownies Made For Gobbling????? Roy, please quit dwelling on food all the time. If not for Sue, for the dog.....
Have fun friend.. Got a meet tomorrow am, maybe I'll get lucky and finish higher than next to last....
Denny
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Hey! I can't help it if I get confused when you take a thread from a truck to airplanes! Geeeeze

Twinky's??? Do they still make those things? I liked the 2 things that had cocanut on them.

Not bad fur face, not bad at all.

Best of luck Mr Hathcock.<G>
Roy

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the
Smoothing
just
think
chamber
the
they
know
You are not going to gat an argument out of me. I simply answered his question as to what a spacer was, not how effective it would be on his engine.
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get
increases
so the law of 'negative entropy ' kicks in and longer piping = less resistance ?

it's a proven fact that longer intake runners increase low-end torque
just as 3 % / 2 % = 150 %

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the
Smoothing
to
with
just
LOL, perhaps you need to do a little research there buddy. There is more than one resistance going on here and a slight increase in one resistance can be more than made up for by overcomming another one.

I never said different but do you know how? I realise that this is another flow question so you may once again be baffled.

Hey, did you figure out the fluid flow in that TC yet, Mr. Trans expert?????
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"Max Dodge" wrote:

or
of
A TBI spacer is not like putting a taranula intake on your engine with a open phlenum under all bores (which by the whay does well above 3500 RPM or so with the correct carb because I have used them). The TBI spacer allows a little more precharge room under the TBI for better flow resposce to flow requests and the two planes of the manifold are still seperated too for good throttle responce
"Max Dodge" wrote:

between
are
Smooth passageways can be a bust for low end to mid range responce with a carb or TBI because some roughness and turbulance is needed for good mixing and atomization of fuel for a better burn. Porting can help top end but it can murder it too if not done properly. ANd again the larger phlenum allow for less pressure drop because of more precharge volume that is avaible under the TBI unit. Flow through a TBI of carb is not constant, it is a series of pulses that increase in frequency as RPM increases and the phlenum smooths thes pulses out a bit because it allows the velocity and mass of the air to continue flow into eare under TBI/carb a few milliseconds longer at impluse minimum, precharge the enlarger phlenum while waiting for the next intake pulse cycle from a cylinder. As RPM increase the mass of the air and its velocity can because a factor in "ramming" the mixture into phlenum for next cycle.
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Ok, I'll repeat myself. TB systems do not depend on vacuum signal like carbed engines do, since the fuel is introduced by a different means. Furthermore, more airmass does NOT allow a quicker response, since the MAF is not inside the intake, but is upstream considerably. Thus it does not register the flow as quickly when put further from the vacuum source.
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Max

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By the time the air flow gets to the cylinder runners in the typical Mopar manifold, the TB is long past being the cause of turbulance. Too much has happened to the air by that point to blame the TB for the turbulance. However, inducing a laminar flow at that point can ease some of the rough trip ahead.

The volume of air in the cylinder will always be the same. Again, the TB spacer is so far upstream as to have little effect on the engine itself. Changing the TB may have an effect, but from what I've seen, read, heard, etc, most times a larger TB drops low end torque and boosts HP.
Money is better spent on intake manifolds, be it a better one or simply porting and port matching on the stock one.
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Max

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You do know that this is not always true, right? Turbulence tends to be cumulative and amplified in it's travels so the sooner you can reduce or eliminate it, the better off you are. Now I am not saying that it will work for his manifold but they do work well for some and that is the reason why their effectiveness is so arguable, pretty much like the performance increase claims of a K&N filter.

think
No, the volume of the cylinders will always be the same. The volume of air in those cylinders is always changing or there would be no need for the TB.

engine itself.
While not always true, it may very well be the case of the current run of DC engines.

Which probably is not the best idea for a truck.

Agreed but that wasn't his question.
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Its always true in the Dodge manifold, given its design.
Turbulence tends to be

Hence my suggestion at causing laminar air flow.

Nor did I.

Never said anything different.

Um, no. Air is elestic. It'll ALWAYS be the same volume. Different density, but SAME volume.

Hence the uproar when Kibucki used to hawk his wares with no solid dyno proof.

Heance the reason why I didn't suggest it til after I answered his question.
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Max

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has
rough
Really? Do you have the dyno and airflow results to back this up? I am not arguing with you, I just want to know where you are getting this from.

density,
Um, no. The volume is based on the amount of air that manages to get into the cylinder in any given cycle and there is nothing all that consistant about that. If this were true, there would be no need for a throttle body.

heard,
question.
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Tom Lawrence did some testing of TB's a while ago, not sure what all it included, but the results were minimal improvements at best.

LOL, nope. If you were correct, compression ratio and cylinder pressure would mean nothing.
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Max

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Cool, now I know not to waste my money on false claims.

into
LOL, do you even know what a compression ration is? Here is a hint, it is the change in cylinder volume between bottom and top dead center and has nothing to do with the amount of air in the cylinder. Adding a blower or turbo does not change the compression ratio of an engine but it does drastically increase the volume of air pushed into the cylinders, hence, the recommended drop in compression ratio to a reasonable level on engines where they are used.
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