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

[Jackpine]

Other than the "sexy" look of the commercial CAIs, I wonder why anyone would want them? Trust me though, I wouldn't have tried making one myself if I hadn't read Bill's thoughts on this!

Even though I love to argue obscure points, I recognize Bill's expertise in this area and I know, "I can take it to the bank".

Thanks again, Bill and Corey, for creating a forum that so far, allows us to "think out loud" and not be afraid of sounding stupid!

- Jack

[Jim Allen]

Pretty coo1!

I'm new here and hesitate to start in such a way, but at the risk of being labeled a "Negative Nelly" after my first post.... is there any proof these mods actually increase airflow? The reason I ask goes back many years to my days as a Land Rover tech.

Late '80s and early '90s EFI Range Rovers had a "trumpet" on the end of of the air cleaner, similar to the part that was replaced in these examples. It necked down to a diameter many people were sure was restrictive, so they lobbed off the trumpet thinking it helped airflow.

I thought it would too, but then I took a bunch of air filters to the late, great Earl Davis for flowbench tests back when he was running the test lab at K&N. I had both a standard Range Rover filter with the trumpet and one modified similar to the way this Ford one is done. No significant difference in airflow. In fact, the trumpet actually flowed slightly more. Earl postulated that the trumpet design actually had something to do with that, smoothing and consolidating air flow, much like velocity tubes will do on carbs. I later backed that airflow test up with a dyno test.. no difference in power the chassis dyno could pick up (admittedly, chassis dynos are "numb" to small changes). Operationally, you couldn't tell a difference, except that the modified horn was noisier.

I won't say definitively that the Ford mod will flow more, or less, than the stock setup because I haven't tested it, but previous experience leads me to ask the question at least.

I have limited access to a flow bench, so in theory, I could test the various permutations of this filter. I have a stock filter from my '05 5.4 F-150 (I am running an AEM CAI). If we wanted to do a test, I could probably make that happen. Bill can vouch for me. I hope!!?

[Grabber523]

Originally Posted by Jim Allen

Pretty coo1!

I'm new here and hesitate to start in such a way, but at the risk of being labeled a "Negative Nelly" after my first post.... is there any proof these mods actually increase airflow? The reason I ask goes back many years to my days as a Land Rover tech.

Late '80s and early '90s EFI Range Rovers had a "trumpet" on the end of of the air cleaner, similar to the part that was replaced in these examples. It necked down to a diameter many people were sure was restrictive, so they lobbed off the trumpet thinking it helped airflow.

I thought it would too, but then I took a bunch of air filters to the late, great Earl Davis for flowbench tests back when he was running the test lab at K&N. I had both a standard Range Rover filter with the trumpet and one modified similar to the way this Ford one is done. No significant difference in airflow. In fact, the trumpet actually flowed slightly more. Earl postulated that the trumpet design actually had something to do with that, smoothing and consolidating air flow, much like velocity tubes will do on carbs. I later backed that airflow test up with a dyno test.. no difference in power the chassis dyno could pick up (admittedly, chassis dynos are "numb" to small changes). Operationally, you couldn't tell a difference, except that the modified horn was noisier.

I won't say definitively that the Ford mod will flow more, or less, than the stock setup because I haven't tested it, but previous experience leads me to ask the question at least.

I have limited access to a flow bench, so in theory, I could test the various permutations of this filter. I have a stock filter from my '05 5.4 F-150 (I am running an AEM CAI). If we wanted to do a test, I could probably make that happen. Bill can vouch for me. I hope!!?

I have to agree with your statements here. It's kinda been a nagging question in my head but I'm new here so I didn't want to seem like the naysayer...I guess in my head the "velocity stack" on the intake is there to improve airflow into the intake tube by compressing and accelerating the air as it flows into the tube. Because of the inverse relationship between pressure and velocity, as the diameter of the tube increases behind the inlet and the velocity decreases, the pressure increases (I guess really it's decreasing the vacuum) in the tube. I guess if my theory's not too far off, that "trumpet" inlet tube serves to increase the density of the air charge before the throttle body...does that make sense? It would improve low-end torque and throttle response but cause slight restriction at high rpm.

[88Racing]

Great ideas everyone shure beets the price of a cai!
Jack,
Might stop at a hardware store or plumbing wholesale house and get some ideas Friday or this week end of what could go into the fender well hole that would not interfear with the inner diameter of the hole and does not have to remove the lip, but can be easily be removed. I will post it if I find something.

-Lars
Forgive the spelling, life on a blackberry!

[SinCityFX4]

You could use those thick coupler pieces and cut a line around the
Outer edge so it seats in the fender well.

[88Racing]

I think I might know where sincity is going with this correct me if I am wrong. Take a no hub coupler like Jack has left over and make sure it has the same ID as the pipe or am I thinking wrong? I know they make a 3x2.5" reducer coupler(problem with this one it has a rib where the 2 pipes meet) or like the 3" one Jack used. Or take the 3" coupler and try that in there also? Is it long enough or will the sides kink in and cause less air flow/turbulance?

-Lars

[kd4crs]

These are all good ideas but I think folks are over-engineering, and over-thinking things a bit. To clarify what I mean I will go ahead and post the instructions, materials list, and pictures for the DWV intake. It really is about as simple and as easy as it gets, no grinding, no fitting, no painiting. Once Bill posts the write up I sent him I will edit this to comply with his wishes. See below:


DWV intake mod for the 2004-2008 F150 with 5.4L engine



Materials:

1. 7.5 inch length of 3 inch inside diameter black ABS DWV pipe.

2. One female-to-female 3 inch black ABS coupler.

3. One rubber downspout connector from the plumbing section of Lowes or Home Depot.

4. One 4 inch stainless steel worm clamp.

5. Small container of ABS pipe glue.



Assembly:

1. Cut black ABS pipe to length and remove any burrs from the ends.

2. Apply a light coat of ABS pipe glue to the end of the black ABS DWV pipe in a one inch wide strip. Apply a light coat of ABS glue to the inside of one end of the female coupler and immediately press the coupler into the black ABS DWV pipe with a twisting motion to fully seat the pipe into the coupler. Allow to dry 30 minutes.

3. Attach rubber downspout connector over end of female coupler and seat fully.



Installation:

1. Remove stock intake tube by removing 10mm bolt holding it in place.

2. Using a large flat blade screwdriver, insert it in the joint at the end of the flex section on the bottom where the notch is in order to remove the snorkel. Spraying silicone lubricant or WD-40 in the joint will help it come out easily. Be careful not to damage the flex section or snorkel in case you need to return to stock.

3. Loosen 4 inch stainless steel worm clamp and slip over end of flex section. Tighten the worm clamp enough that it will not fall off.

4. Insert the end of the 3 inch black ABS DWV pipe into the flex section of the intake and slide it into the flex section as far as it will go.

5. Reinstall stock intake tube and replace 10mm bolt.

6. Slide the 3 inch black ABS DWV pipe out of the flex section and seat the downspout adapter in the fender hole while compressing the flex section.

7. While holding the flex section compressed, tighten the stainless steel worm clamp to hold the black ABS DWV pipe in place.

IMPORTANT: If the flex section is not compressed the DWV intake mod may vibrate or rattle.

Pictures:


Ingredients for the DWV intake mod

Finished DWV intake mod

No restrictions here! Full 3 inch diameter end to end.
Additional pictures are in my gallery.

[Buckeyes903]

Quick question about the mod. :idea: I did this mod about 3 weeks ago, but I never un-hooked the negative terminal to reset the computer. By now has the computer learned to run with the extra air, or would it be in my best interest to reset the computer? Thanks for any help!

[Power Hungry]

Don't bother with the battery. There's really no reason to mess with it when doing the snorkel mod. All that's really happening is that the modest restriction is being alleviated allowing a little more flow at higher RPM. However, this mod DOES NOT AFFECT the Mass Airflow Sensor and doesn't significantly change AFR like a CAI does. The MAF sensor still accurately reflects the airflow into the engine and the computer handles everything from there.

[Buckeyes903]

Sounds good to me.