The kd4crs/Power Hungry/Gotts Mod (revisited - and with pictures)

[Jackpine]

I entered this post a while back: http://dygytalworld.ehost-services13...12&postcount=2 No one challenged me on it (which doesn't make it true, but it's my feelings on the subject).

I honestly don't see what a "super" filter does for you after 100 miles (except cost more than the OEM brand). Now a cheap knockoff can be a problem - for instance what would happen if the cheap one developed a hole in use?

Again, I'm quite open to having my opinion changed - all I need is a good counter-argument.

- Jack

[txarsoncop]

Ok, for those of us who gleefully cut off our Helmholtz resonators (learn something new every day)...

What do the more learned among you think about this information?

Helmholtz resonators Caution: MUCH geek-speak here!
Although this dumb firefighter was able to get the gist of it.

• They dampen resonance... Duh.
• They make the intake air act "springy" so it fills the combustion chamber more effectively giving us better combustion.

Hmmm, not so sure whipping out that SawZall was such a great idea after all...

Do we need to try to get someone to flow bench or dyno the with and without resonators versions to see if there's a real difference? Seems to me that would be the only answer. Dyno both versions on the same truck and see what the results are.

[jimmyv13]

If they are so beneficial, why don't aftermarket CAI's have them?

[Jackpine]

Bill - I think you're right on the tests needed with and without the resonators. And, don't feel bad about finding that article a difficult read - part of the reason you did is that the guy can't write! He uses words without regard to their meaning so that several sentences are nonsensical. However, I suspect his math is valid for the systems he's studied (which does not match our trucks).

As I said somewhere near the beginning of this thread, fluid flow (air in the duct acts like an fluid) is a very complex, and poorly understood process. I say it's poorly understood because the mathematical models make too many assumptions that allow it to be studied, but that do not allow a precise prediction of the outcome (there's always a bit of error between the predicted results and the actual observed results).

I was concerned about the possible bad effects of turbulence in the duct and it would be very easy I think to create a sort of "standing wave" that would interfere with movement of the air mass into the engine. I would still like to have a smoothly "curved" snorkel section that would turn to match the angle of the intake tube more smoothly than what I have right now. I think the sharp angle I have at the bellows can create problems.

The article seems to say that the resonators act to reduce the effects of turbulence and standing waves.

But, in our case, the resonators were designed for the original duct with the factory snorkel. I honestly have no idea if they are beneficial with the larger intake opening or are actually harmful. However, I felt leaving them on was more prudent than removing them. It also allowed me to return the setup to stock if I chose.

I can only report that the truck seems to run well at WOT and I've noticed no loss in power or adverse effects on gas mileage. Other people seem to say the same for their mods with the resonators removed.

So, the effects of the resonators are probably not enormously significant. (And, sorry if I got "geeky" too)! :o

- Jack

[Jackpine]

Originally Posted by jimmyv13

If they are so beneficial, why don't aftermarket CAI's have them?

Jimmy, your question is good too. My uneducated guess is that the aftermarket CAI manufacturers don't have the engineering brainpower or facilities that Ford has. They take a more "trial and error", "common sense" approach - similar to what we did when we "reasoned" that a wider snorkel would be good.

- Jack

[txarsoncop]

Jack,

Thanks, you confirmed what I thought I was reading.

Granted I understand fluid dynamics are tricky, tricky. So take my musings below with a grain of salt. But, I live next to a PERFECT example of fluid dynamics gone wrong. Plus being a firefighter and having a master plumber for a father I understand the "common sense" wet side pretty well.

The author of the article was referring to a single cylinder engine and, at first, I thought well that's totally wrong for our 8 cyl application. But then I thought I remembered that with a V8 only 2 cylinders are opening at once correct? So it's not really that much different? Except for a convoluted intake path, a filter media and unexplained holes in both the resonators and intake tube.

If I'm remembering correctly I believe you posited somewhere here that the holes might actually be to remove some of the "springyness."


I rounded the edges of my PVC with the Dremel and a file because it just seemed to make sense. Probably didn't make a difference but...

[88Racing]

Here's some ?'s for you guys also to ponder.

Do you ever think of where our filter is on a stock location compared to a cai?

Do you ever think of how much more volume a vacuum needs to displace when you have a cai?

Do you think the snorkle nozzle help to create vacuum and velocity at the same time?

Just some thoughts as I was doing a fire pump test today and had to use reducer nozzles to increase flow pressure at the hose monster pitot gauge.

Lars

[kd4crs]

I just got around to purchasing the alternate rigid 3 inch tubing that fordmt08 on f150onloine.com used for his intake modification and it looks like it will work well installed a couple of different ways. The tubing required is made by Spectre Peformance. It is part number 8741 for the black color (8742 is Red, 8746 is Blue, 8748 is Silver) and it is called: 3" Flexible Air Duct. It is priced ~$20 and should be available at O'Reilly Auto Parts and Autozone stores. I installed it completely collapsed using one of the two connectors that come with the kit to go into the fender inlet and using the downspout connector to connect to the stock flexible section. It fits perfectly and does not require any hose clamps. I will be testing it out with my Gryphon Custom 87 performance and Custom 87 towing tunes this week. This variation completely eliminates any possibility of the downspout connector collapsing or getting sucked inside out.

[schwinn1weld]

Originally Posted by AgentOrange

Hi guys & gals, brand new to this forum. I stumbled across it while checking out other homemade CAIs after tinkering with one of my own and this was the first one I've seen that had an excellent one for the 2004 +. I like the caron fiber idea.
Here is a pic of what I came up with (hopefully the pic works):

Looks Great, but what did you use to cap the holes on your main intake tube? Looks awesome how you did that...

[Longshot270]

First I want to say WOW! this thread has exploded since the first time I skimmed over it. I did the gotts with my 08 4.6L and here are some of the pics.

The first one is the section of PVC that goes into the fender and the second shows how it fits. The big section taken from the 'bottom' of the pipe lets it fit in the flat area of the fender hole snug. The little cuts on the 'top' help hold the pipe in place. I cut it like that because I didn't have any large grit sand paper and I think they work pretty well because they bend to hold the pipe in place. I also used a 3 in flexible coupling to attatch it to the intake. Pretty soon I may work on a ram air type of intake but I'm still working on the idea. Making stuff fit in the 4.6's is difficult. :nerd: