It's not the same design, but Bill at PHP dynoed a 2004-2008, don't remember which year, but they are the same. He dynoed a CAI, and then the stock intake minus the restrictive snorkle that goes into the fender. The CAI was only about 5 hp more than the stock intake with snorkle removed.

 

Okay see now you are talking about what I was wanting to hear. I have the snorkle(never knew it was called that)removed and a drop in K&N filter. My thought was that it would be comparable too, if not the same as a CAI set-up because all that would be different is a plastic inake tube as opposed to some shiny one that says K&N on it.

 

I've just read this entire thread and I'm confused but I'm going to take a guess at the answers I think you are looking for



#1 - when you remove the snorkel you allow hot air defeating the purpose of the snorkel


#2 - your silencer chokes down smaller than 2.5 inches anyway


#3 - look at the picture of the measurement comparrison photo's

STOCK




MODIFIED




#4 - to gain maximum from this mod one should remove the silencer and get a custom tune

#5 the way you are set up right now you are still having the silencer choke your airflow so you are doing nothing but sucking in hot air and maybe providing a slight increase in throttle response after you are over 45-50 mph

 

and one last thing your '98 has a smaller inlet than the newer trucks do so you can always upgrade to a '01-up piece that covers the filter (even the non heritage body style trucks with a 4.6 2 valve will work)

 

Hmm. Im confused as to what you mean when you talk about a silencer. My intake tube is gutted completely with the exception of the mass air flow sensor and a K&N filter. Also, I believe the piece you have shown is for a v6 model. The piece that I have is much longer although the end is that same 2and1/2inch diameter.So I removed that piece so air could be sucked straight in via the filter box. Also, aside from an occasional heat shield what would keep a cold air intake from sucking in all of the hot air from the engine compartment. I understand what you are saying, but I dont understand what all of you cant understand. I cant think of any other way to say it.

 

Enclosed filters don't suck in as much hot air as an open filter does. The heat shield on the K&N's has several gaps that allow hot air to bypass the shield. CAI's with a box that connects to the fender only suck in outside air.

 

So would you be willing to say that a performance filter in a stock air box would be comparable to a performance filter within a heat shield?

 

Yes, as long as the intake tube that runs into the fender has been enlarged to 3 inches.

 

Okay so that being said what kind of modification or cutting do I have to do to my filter box or air box. Because if I were to put a three inch pipe on there the opening to the filter box is still smaller then three inches. So it would be increasing the size of the snorkel to 3 inches, but not the opening on the filter box. Do you understand what I am getting at? Im goin to take some pictures here in a little bit so I can show you what exactly im referring to. I dont think I can properly explain it without pictures.Hopefully the pictures will clear all of this up.

 

I dont know if this matters but here goes. I had a k and n filter set up that just sucked air from engine compartment. On my scanguage it would read at best 15 deg above ambient temp. some times idling in traffic it got 50-60deg abobe ambient. Then I did the gots mod put my stock stuff back on now I am no more than 3 deg above ambient going down the road. And Idling it gets 15-20 deg above ambient. Now with the stock setup and gots it comes down from the 15-20 deg above ambient pretty quick once back up to speed going down the road. With the K and N set up it took a while to get the iat to come back to the 15 deg above ambient.

I noticed when pulling a trailer in hot days above 85 deg my truck was a real dog taking off with the K and N set up now it seems alot better with the stock setup and gots. I am not sure on how hot the IAT has to be to start pulling timing out of the engine but the butt dyno said it was alot.

Duane

 

This is where my modification took me. First off my 97 air box inlet was 2 3/4" od inlet so I looked for an 99-03 air box and aquired one for $70 complete with airflow sensor (now have a spare). Followed the rest of the instructions and then didn't have to but aquired a used elbow as well an removed the silencer etc, (again follow instructions). You have to remember in the old days we used to flip the top over on the air breather for more airflow (is always a good thing) but was pulling hot air from the engine bay. Think about this in a velocity sense is the path of airflow always follows the path of least resistance. The aftermarket cai's try to achieve the same thing but try and pull the same un-restricted airflow from under the engine bay or through the fender (same as gotts) with the exception as being a little more costly for minimal hp gains for the difference in expense. So depends on where you think your hard earned money is more well spent. For me it justifies what i spend on a tuner etc. I have run the drop in K&N as opposed to the paper filters and don't really se any difference. The choice is yours but by all means try it. Lately here in the Dallas area when the oat is in the 100's you may see iat's running 30 higher summer is not going to be the most mpg efficent period however I'm really enjoying this 90deg cold front right now.

 

what i think you are asking is why even bother putting the pvc pipe in there when it really doesn't even fit the hole you are trying to put it in. am i right? you have to make the pipe smaller to fit the gaps.

the purpose of the pvc is to "bridge the gap" so to speak. it just so happens that the 3" pvc is the largest I.D. pipe that will fit in that hole. the bigger the inner diameter, the less restriction on the airflow. the less restriction on airflow, the easier it is for the engine to bring in air. when you put the pipe in there you are completely closing the intake off from the engine compartment. this is, theoretically, going to bring colder air into the engine and thus, give you more power.

 

I totally agree with everything you guys are saying. And not trying to be facetious at all, but so far im still not satisfied as far as a answer. I have been really questioning buying a cold air intake because I hear that they arent all they are cracked up to be. I was not so much wanting to know the different performance of stock vs. CAI because that is the stuff I have been told to look up, and was somewhat off subject from what I was trying to ask. I am trying to understand what would be the literal difference between cold air intake(assuming there is no box covering) and my stock plastic intake with a K&N filter in it and my snorkle removed as well as the silencer. Maybe I should have tried harder come right out and ask straight up what I was thinking, but at the time I didnt know how to word what I was wanting to ask..so I did my best. I think that ideally there wouldnt be much difference, but I cant get any of you on the same page as me mentally on the subject. I had thought that if a cold air intake can suck in air from the engine compartment and still provide more horses then so could my "modified" intake.
Is this making any sense to any of you? haha

 

If you will look at this thread and pay careful attention to post #9, although it does not specifically come right out and answer your question point blank, I think the inference is there.

https://www.f150online.com/forums/ch...s-intakes.html

 

it's off of a '00 7700 series 4X4 with a 5.4




as far as your removed snorkel (and silencer) and an aftermarket CAI doing the same thing then yes hence the reason for the tube "bridging the gap" as mentioned above to get your motor the coolest air as fast as possible to make maximum horse power




the stock intake system has the coolest intake charge followed by the airforce one which is no longer made (but you could find a used one)


I unfortuantly do not have the time to buy one of each intakes and strip my truck just to dyno it 100 times and put it back together




will it flow enough air? YES

I ran the gotts mod after i sold my K&N and I maintained the same fuel trims even running full bolt ons and 24# injectors