let's talk airraid throttle body spacers
 

http://www.airraid.com/spacers.asp
Here's a 5.4

http://www.truckworld.com/Truck-Test...150-Engine.jpg

Now, let's first point out that many racers will argue that when porting a lower intake (where the air is distributed into each combustion chamber and the fuel is injected on most v8 fords) to not polish the ports any smoother than 80-grit in order to increase fuel/air mixture. It's a debate that has never been proved or disproved because either way the gain is minimal.

That said,

1) if the fuel is injected at the lower intake near the cylinder, what exactly is the Poweraid TBS combining with air in order to make this "super atomizing mixture"?

2) if it is beneficial to "spiral" the air at the Throttle body, ok. But how is that "spiral" maintained once the air hits the upper intake and has to be distributed through 8 runners?

3) if air velocity is good (as in forced induction through supercharger), than how can reducing air velocity be good?


Just some questions.

In 7 months of reading almost all of the posts in this specific forum, yesterday was the 1st time I saw anyone post that they were buying (or even considering buying) a throttle body spacer for their '04. I don't think that you're going to find many members looking to debate the benefits of this as a quick bolt on performance enhancer.
However, it TBSs are discussed more regularly in some of the other forums (Engines, OTher Aftermarket), and the general consensus is that they are perfectly good...if you want an expensive paperweight. :D

John

I posted it only because it was a recent topic.

They look like they might make good cupholders too, for what its worth. Expensive, but the helix core design would probably keep the cup from falling out easily.

It might actually help in the mid range RPM, but IMO it will hurt you at the high end.

Grim
Mechanical Engineer, Flow and Combustion

ok, I'll bite and discuss it.

I believe that these "swirl plates" can be of some benefit in intake systems where no effort is being made to promote an atomized mixture. However, in the 5.4, as well as other ford powerplants, ford has incorporated what they refer to as "CMCV" or charge motion control valves, within the intake runner for each cylinder, that are servo controlled by the PCM. This mechanism is designed to produce controlled "turbulence" or "swirl" at different rates depending on engine speed, load, etc.

so, worth it for the 5.4? probably not it's already there.

my 2 cents....

but those valves are located near the injectors on the lower intake (I would imagine anyway).

And what does "atomized" mean???


"if it's a penny for your thoughts and you put your two cents in, someone is making a profit" - Steve Wright

Process of changing a liquid to minute particles or a fine spray.

This is true, but if you've ever looked at a 5.4L 3v intake manifold it seems like this swirl plate would have no effect. The air enters through the throttle plate into a large volume area between the cylinders called the upper plenum. The individual runners dip down into this like straws in a drinking glass. Then when a cylinder travels from top dead center to bottom dead center, it draws the air into it. Each cylinder in a V8 starting this draw 90 degrees apart. IMO the "swirl" would be long gone by the time it made it down the intake runner and through the CMCV.

Auto Manfs. employ whatever they can to get .1mpg, or a couple extra horse. Somehow I doubt that every OEM is overlooking this technology.

-ii

If I remeber right, It is not important that the swirl gets down into the cyclinder as much as the swirl being where the air hits the gasoline during atomization. Breaks it down into finer particles making it burn more efficient.

Steve, the point is, it doesn't hit the gasoline until right before the intake valves...as Izinbloom said, how can you expect the air to keep that "swirl" when it is transformed from one inlet into 8 individual runners?

All I can really see it doing is slowing down air velocity and throttle response.

Im no gear head, but, it seems the "swirl" will help dispurse the fuel by "spreading it out" and help with the combustion.....maybe?(Like Sticker Steve said)

Or am I way off?

way off.

theoretically, a swirl will help mix the air and fuel just prior to combustion. Theres really no issue with dispursing the fuel in teh chamber...it all gets combusted.

OK.

I got a lot to learn.

:D

check it out...

this is the best engine cutaway I could find (and its a pretty cool pic)

http://www.fnsweet.com/pics/events/n...as_ford_30.jpg

The idea, as described by an Air Raid employee, is to swirl the air thereby somehow making a more dense charge in the combustion chamber. I do know, even though I am no engineer, that if you make a more dense air charge in the combustion chamber, you will have more oxygen in the chamber, therefore making a bigger boom. What I do not know is, how swirling air can mame it more dense. I also slightly disagree with a previous poster in that in the higher RPMS, the spacer will have a lesser effect due to the small "swirls" on the spacer. I personally think that the spacer would have to be about 20 inches long in order to have a swirling effect. I think it could possibly produce a "tumbling" effect caused by the low pressure area on the backside of each maghined "swirl". Does it work? Beats me. I have several customers that swear by them, for mid range performance (torque). Will it hurt your high RPM performance? I seriously doubt. I welcome proof contrary to my theories. I am but an ignorant guesser.