Ok assuming CAI companies know what they are doing and the principles of flow velocity and capacity haven't changed why don't we see CAI with expanded areas were the intake tubing curves? It seems like they should expand at the bends then constrict back down to increase the velocity on the strait sections. Is this too hard to do or am I missing something?

 

Seems like a good point. Might be too expensive, I dunno though.

 

AEM V2 is the only "innovative" intake design for a long time...

Seems like if you were too widen the pipe on the bends, your intake air speed would slow down.

Damn good question though.

 

Actually, the V2 reminds me of the iceman design in the way that it tapers towards the TB. I was always convinced by the argument that this was a good thing as it would increase air velocity, but recently I read a thread by a race engine builder (endyn) who said that it is better to slow the velocity just before the TB so that it gets higher pressure?? They use piping that is 3" that expands to 4" near the TB and then goes down to TB size. Can someone explain this?

 

That doesn't make any sense...slower velocity = higher pressure?
Increased intake velocity is always a good thing, for throttal response and for maximum intake volume.

 

but it would be increased on the strait sections. One of the problems I see is that we have a bend right before the throttle body. If you could fabricate a system that runs strait into the throttle body this might help, but this would cause some fitment issues.

 

Expanding the bends will slow the flow, by dropping velocity. Constricting the straight pipe down from will drop velocity and cause turbulence. In the ideal shape of a flow bend would be something similiar to a trapezoid. In the bend the fluid will find the shortest route which inturn maximizes velocity. The shortest route will, obvisiously, be the shortest side of the turn-this is where most of the fluid will flow. Therefore, you want to keep the least amount of area on the longer sides. Expanding the bends will counter-act the velocity with an unnecessary pressure drop. Constricting the pipe after the bend will most likely cause unnecessary turbulence. So, in theory you would want shorter area in the bends, to prevent velocity spikes and drops.

 

Seems like if you were too widen the pipe on the bends, your intake air speed would slow down

 

I don't fully get why he said that. I can see the increase diameter directly prior the TB for the roll-effect, or turbulence of the flow for increased atomization. This would cause lower pressure before the TB. In thought if the last section of pipe was oversized, and long enough, then air storage would be available for acceleration from a stop. Anyone else?

 

Umm... the speed of the air in the intake before the TB does not really mean crap. What ya want is a nice smooth wide path for the air to flow. The idea is to minimize any air resistance. The only spot a faster air speed is needed is right as the air shoots into the cylider (for good air/fule mixing), and this is done by your intake manifold runners NOT your air intake from your filter to the TB. making skinny sections before the intake manifold is only going to restric your flow.

 

So I guess my point would only be relevant if fuel was injected at the end of our CAI? I'm retarded. I was thinking you need to slow the air down in the bends but that is only relevant if you are carrying fuel, because the fuel can't take turns as well as air and needs a little more space so that it doesn't slam into the wall of the intake. Oh well.

 

I remember seeing some goofy *** fat looking cf intake tubes that claimed higher air flow. And I recall someone before aem's v2 with a short ram that had a 4" diam chamber. These were no name intakes or cheap ones.

 

They probably just don't want to waste time since no matter how different the technology, there is only 1-2 HP difference between them all.

 

Why does a real RAM air intake work then (e.g., trans am)? Don't they have a similar intake design or is it radically different?

 

Because it creeates a more advantageous pressure differential between the intake tract and the chamber when the vehicle is at speed. And a ram air system isn't actually all that simple to design properly, motorcycle manufacturers are constantly tweaking their airboxes to get the greatest possible benefit.

 

I'm gonna try figuring this out one last time. So if this is true, wouldn't an intake design (decreasing diameter as it approaches the TB) that sped up the incoming air work similarly (albeit on a small scale)?

 

Not according to Bernoulli.

As the velocity of a moving air column increases, it's internal pressure drops. A ram air setup generates pressure by stuffing air into the system, ala ramcharging (on a small generally micro-pressure scale), without trying to manipulate the flow through a change in velocity. While charge velocity is a very important concept where cylinder filling is concerned, it is primarily set by the intake manifold and not the intake tract. That's not to say that the intake tract is useless and should be gigantic, just that most of the air velocity in the intake runners is generated by their size, length and intake plenum volume.

 

Though, I totally agree with the comment about the intake before the TB, some companies are suggesting(or lying) that a swirl affect of the intake air column will increase atomization. Their main design for this occurance is the TB spacer. Not that I believe the TB spacer makes a difference, or the intake design of the prior posts. No the less, they still claim it. That's why I suggested it.

 

Exactly, also the ram air design should deviate from a opening of the hood to a better point of stagination-such as in the front bumper.

 

Thanks for the info. I'm now rethinking my recent purchase of a used Iceman (velocity stack design), but then again, between one and the next CAI it really shouldn't be that noticable (hp or 2 here or there).

 

I have an Iceman and am very happy with it. My only point here was that there aren't any major gains to be had from one design to the next, the most important thing (other than filter location) is that the airflow path is a smooth one. The Iceman accomplishes both, and you don't have to cut into the sheetmetal to fit it.

 

i don't understant how a swirl effect would do anything.. once swirling air hit the throttle body butterfly, wouldn't the air would become more turbulent than if it were just flowing straight in?