Well sir is completely within you rights to ignore any scientific theory or fact that disagrees with you. Just please remind everyone again you have no proof or data to support you assumptions.

As for me I’m moving on to my own assumptions. I believe that the black soot that comes from diesel exhaust is really the remnants of artificial black holes created by the extreme pressures inside the engine. The diesel manufactures want to tell you its un burnt fuel, but this is a lie to save them from liability. I’m now attempting to rig up a gamma ray detector so I can see the gamma burst from the black holes creation. I became convinced this was happening because people became green when near my truck. I’ve noticed that with heavily modified trucks that this effect is much stronger. I want to encourage everyone to wrap their trucks in tin foil to block any harmful radiation coming from the engine. I only hope that someone with a very heavily modified doesn’t create a black hole stable enough to set of a chain reaction and grow thus destroying the planet. I will keep you all informed on my progress, but until then be safe.

 

Wait just a minuite. A jet intake is *NOT* the same as a truck's turbo intake by any means. There's no filter, relatively long intake tube with the characteristics pointed out by batgeek, and correct me if I'm wrong, but the description of the vortex using the "drain" theory was based on it being the size of the entire intake. Not a very small one (relative to the size of the intake). In other words, I'm not convinced at all. Until someone has a picture of a PSD with a transparent intake the same shape & size as stock, I'm quite unconvinced that they exist in there.

Even Mythbusters goes through extreme measures to demonstrate not with numbers, but actual working models of what they're trying to show. In our case, a clear intake on a dino in a humid environment (or the dry ice idea I had earlier) would do the trick. I realize that's a TV show and chances are they have 2 or 3 "ernesteugenes" working in the background, *BUT* seeing the intake of a jet engine and assuming that the mechanics involved in creating those vortices are the same as inside our trucks' intakes is a big stretch. Kind of reminds me of one of Adam Savage's most famous lines in the show: "I reject your reality and substitute my own!".

Tell you what. I'll find the specs of the RR engine and see if I can continue the calculations that Gene started. However, even if they do work out, (and I'll say it one more time) I seriously doubt that a vortex like the ones in the pics can form inside our intakes for the reasons stated by batgeek.

I'm off to do some calculating. My wife is going to kill me -- I have yard work to get done, a couple trucks to wash, and an office to clean up. If I end up single, IT'S ALL YOUR FAULT!!

Joe

 

I've already run into problems. First of all, Gene chose what I am seeing as VERY small engines for his numbers. The pictures shown are large engines, like on a 777 or 767. Those engines produce 70,000 to 80,000+ lbf of thrust. 16,000 lbf of thrust is a much smaller engine. So, I'm using the larger engine as a model. Second, I have no clue what some of the acronyms mean that are used in the data sheet I found. So now I get to chase those down, too. See it here:
http://www.jet-engine.net/civtfspec.html

 

Another thing to consider is that the vortexes in the jet engine pictures come out of the engine and go directly to the tarmac or some other surface. I believe they are feeding off of the warmer air next to the ground, just like a real tornado. That's a condition that doesn't exist inside our intakes. I would bet that there's almost always a vortex between a running jet engine and the ground, those pictures are just under conditions that they could be seen and photographed. I agree with batgeek, the airflow into our turbos has very little in common with the airflow into a jet engine, it's not even close to a valid comparison.

 

At the risk of possibly losing the one convert I've appeared to make, I'd like to point out that any vortex that might form in the inlet of our truck turbo will be approximately in the center of the inlet, and not off to one side like the vortex for the jet engine inlets shown in the 3 pics. There are at least two reasons why this is so, which I'll try to explain below. Also like I've previously stated, the vortex will form at the center of the compressor wheel and move outward toward the filter element, which is why a very symmetrical, free flowing element can encourage instead of dampen the formation of such a vortex!

The pic is of a turbofan jet engine, and the turbine fan at the front (shown in green) is a lot like a radiator cooling fan, and the turbine fan shown here Click for full size image of the turbine on the hot side of our truck turbo. For this type of fan, the incoming air passes through the front of the fan and continues on out the rear, and for a jet, then into the core compressor and then the burner, where it's mixed with fuel and combustion occurs. For this type of fan, there is minimal air flow at the center, and the flow velocity of the incoming air is highest at the perimeter of the inlet, and this is why the vortex forms there as shown in the pics.

On the other hand, the compressor wheel for our truck turbo shown here Click for full size image , is a centrifugal air compressor, and it has a much different air flow geometry than for a turbo fan. Centrifugal compressors work by using a vaned wheel that looks somewhat like a flattened fan, but air does not flow through it and out the back side as is the case for a conventional fan. This type of wheel imparts a twist or spin to the incoming air stream, and sends the air streaming outwards from the center of the inlet. The compressor wheel needs to spin at over 100,000 rpm in order to sling the air molecules to the perimeter of the wheel with enough centrifugal force to build the boost high enough to get good air flow through the turbo, and into the engine.

I've calculated that at 80 F, the speed of sound is about 1140 fps, and the air flow velocity in our turbo inlet is about 830 fps when the engine is under a heavy load, and flowing 500 cfm into the inlet. In addition to the compressor wheel imparting a spin to the incoming air flow at the center of the inlet, any vortex that forms has to be fairly centered in the inlet boot because frictional forces at the perimeter of the boot would tend to dampen it.

 

That's why I've offered up half the cost to instrument a truck with an open element, symmetrical filter, to do a test and get the measurements. The sensitive AFAFG=Air Filter Air Flow Gauge that I've described is more than adequate for detecting the presence of the air flow fluctuations/perturbations indicative of a vortex.

I'll tell you what I'll do. It looks like you've got an F250, and I think I read you've got a suitable filter, if you can hook up a load and pull a grade so as to generate the 15-17 psi of sustained boost to form a vortex, and make some careful measurements, I'll pay 100% of the cost for you to do the mod described in my post #40 here. Just drill a hole in your air inlet tube and install a barbed fitting like I did, and get the second gauge in the parts list, and your good to go. Also, that gauge along with boost will be very useful for assessing the + or - effects of any other performance mods you do in the future.

 

The intake of a turbocharger is basically the exact same shape as the intake of a jet engine, only much smaller, but spinning at 100x the speed.
Wouldn't the laws of nature still apply?

 

Since this is a thread on air filters, I thought I'd pass this along. This is a compilation from various sources, and I'm developing a calibration curve for CFM vs # of inches of H20 restriction for my air flow gauge. Since I've got an AIS, the full scale 15" H20 reading on my gauge corresponds to about a (15"/16")700=650 cfm flow, which is more than adequate for my early 99. Any small +and- fluctuations in air flow about a given reading, are indicative of turbo inlet instabilities!

So far, since my change from a cone to the AIS, I've had no tell tale sounds when pulling grades, like with the cone, and so far I've measured no fluctuations in air flow, but I still haven't had an opportunity to pull long steady grades with my new gauge, and experiment with different throttle settings.

Flow Restriction: This report presents flow restriction of a clean filter resulting from an increasing airflow. The differential pressure restriction across the filter is reported in inches of water (IN H2O) versus Air Flow in cubic feet per minute CFM.

The Donaldson filter (6.0 L OEM) at 775 CFM gives 4.9 inches of H2O
The Donaldson filter (7.3 L AIS) at 700 CFM gives16 inches of H2O
The AC Delco filter at 350 CFM gives 6.25 inches of H2O
The AMSOIL filter at 350 CFM gives 6.0 inches of H2O
The Baldwin filter at 350 CFM gives 5.75 inches of H2O
The Baldwin filter at 500 CFM gives 16 inches of H2O
The K&N filter at 350 CFM gives 4.6 inches of H2O

 

I believe doing this will protect you from vortexes of doom, black hole radiation, alien mind control, government mind control, nuclear strikes, and from increasing the resale value of your truck. The picture is that of a Dodge, but I believe we can use the same method with our trucks. Now if you'll excuse me for a while I'm off to the store to by Reynolds wrap. http://www.livevideo.com/video/ECB39...inum-foil.aspx

 

Actually I think the turbofan inlet is much different than our turbo compressor inlet, and unlike stated elsewhere here, I think the pics show a fairly rare event, not a common one. As seen in the pics, the vortex there is going in at the side of the inlet where the air flow path is fairly straight, and it doesn't have the natural spin imparted to it like is done by a compressor wheel.

Bottom line is that I think the pics show a rare event that forms just like a real tornado in the updraft of a thunderstorm. Such updrafts are very common, but it's a rare event when enough spin gets imparted to the air to form a tornado from an updraft. On the other hand, the compressor wheel is constantly imparting a considerable spin to the incoming air stream, and if the air flow cfm (boost) is high enough, I think a vortex is trying to form during most moderate to heavy engine loads, but the convoluted flow path through a stock or an AIS type air box is sufficient to dampen the formation of the vortex in most or all cases.

 

I kinda stopped reading this thread, but i just caught up on it now, and its some good reading.

 

Agreed. As I posted in Gene's TAG thread some time back, I agreed that straightening the flow right in front of the turbo was a good idea. As for actual vortex formation, I'm still not sure, but a TAG would certainly reduce or eliminate the possibility at no cost to flow. So it would appear to be a win situation.

BTW Gene, what kinda #s is your gauge showing you? Is there a vacuum in the intake? Wouldn't that indicate an airflow restriction, or am I off track??

 

Please read post #81 and #40, and let me know if you're interested in a 100% offer. You've got much better hills than around Dallas, TX and your measurements would carry authority. Can you hook up enough load to run up South mountain or some where like that and slowly vary the boost from 10 to 20 psi?

 

See post # 83 to see how I calibrate for CFM vs the restriction I measure with the gauge. You've also got the right stuff, authority on FTE, hills, and a Baldwin filter. Read Posts #88, 81, and 40, and let me know if you want to be the paid volunteer, being from Tenn would seem to fit right in here!

So far I've measures a max CFM of about 450=(10.5"/15")650, pulling the hill up to the Breezewood exit of the Penn Turnpike. We'll see what I get when I hit the big mountains out west. Also, there I can slowly vary the boost to look for any fine grained fluctuations in air flow.

 

I have some of the requirements, but missing three critical ones. Time, an appropriate load, and a good enough grade without driving a fairly long distance. North Texas isn't exactly the place where I could find long hills. That's why I was thinking a dyno would be better for a couple reasons. One is no limitation on duration of the test (as opposed to going up a hill then back to the starting point with a heavy load), and two you can stand next to the engine and watch what's happening under the hood. However, I'm also not too sure (and I'll plead simple ignorance here) that a boost/vacuum gauge will tell you if there is a vortex present or not. Maybe you can explain that for me.

I would love to do this, but I just don't have the time. In fact, I had to stop playing with the jet engine numbers to get started around the house. I did find a really cool simulator here:
http://www.geae.com/education/engines101/index.html

Go to "HOW JET ENGINES WORK" at the top of the animation window. You can go through each part or go straight to the section called "Test Fly a Jet Engine" by clicking the arrows at the bottom of the animation. The thrust and RPMs under different flying scenarios are interesting.... By the way, that engine simulates the GE90 which is capable of 117,225 lbs of thrust at take off. Pretty impressive...

Gene, if you get a chance to work through some numbers, please put them here. I'll try to later if you haven't by then.

Joe