I installed a K&N replacement filter the other day and heard somebody on here talk about removing the silencer for improved flow, but I couldn't find mine. Didn't really look hard, but I figured I'd ask the experts here instead of waste time tearing my truck apart.
Also, has anybody took their air intake system apart and used a dremel tool to smooth out all of the sharp edges? I was thinking about making that one of my projects this spring just to see if it helped.
BTW, truck is a `99 with a 5.4.

 

I removed my silencer this past weekend but have yet to do the air box mod I will probaly buy a fipk insted of doing the box... I cannnot find the article on the silencer but it is here somewhere...search is down
the silencer is in side of the oblong part right before the airfilter housing you know it has the lines on it the other end has the 2 vacumm hoses hooked to it ...to be honest maybe some one can find the articles I looked for about an hour online and cannot find it to save my life.......

and let me know about that intake smothing Iwish I had a camera I would take some pictures of that silencer mod

 

The silencer is in the black plastic oval shaped piece of the intake that goes from your filter housing to the throttle body. take this out by loosening the two hose clamps, one on each end. Then look in there: What you'll see is a real small opening compared to outside dimensions of the curved piece. What you do is: Take this little round piece out, it is the silencer. The way i done it was: I just took a screwdriver and some pliers and pried the silencer away from the side of the actual intake, and the pulled on it, it was pretty hard, so i just "broke" the silencer in to pieces by prying and pulling on it, and it eventually came out. After i was done, I don't know if i freed up any "power", but, it sure sounds a lot meaner.

 

Thanks for the information!

 

Sorry to say my 98' 4.6 xlt s/c doesn't have it. I removed the whole assembly from the air filter to the throttle body and it's a clear straight pipe in the plastic elbow piece.

Anyone else missing this piece? Is it only the newer vehicles or what?

 

my 97 has it!

 

Hey p_ferlow, I couldn't find mine either.
Maybe we are just missing what they are talking about.

 

pictures, please!!

 

Yes, somebody please post some pics of this silencer thingy.

My 90 deg bend plastic intake pipe is totally smooth through-out so not even something missing there.

?

 

I took my whole air intake assembly apart last night and couldn't find the silencer. It is smooth and doesn't even look like something is missing in there, much like p_ferlow said.
I did go through the whole system with my dremel tool and remove all possible impediments to smooth air flow. I even blended and smoothed the throttle body intake. I also drilled about 30, 1/2" holes in the filter side of my airbox to allow air to flow directly into the K&N filter, all holes were also angled around the edges. I spent about an hour doing all of the mods and think that that is about as good as it's going to get with the stock system.
I may wrap the tube in heat reflective tape to help lower the temp of incoming air this summer, but I doubt that will make much difference, just one more tiny thing I can do that is cheap and theoretically helpful.
There may have been some performance gains, but my wife usually drives it and it is a rocket compared to my Nissan Pathfinder. It does sound nice, though! Once I mash the throttle, it sounds like small children are in danger of being sucked into the motor and definately turns heads.
Can't wait until I get the Flowmaster installed, maybe it will help maximize the intake mods.

 

It's there guys, you just don't really realize what you're looking at if you don't know what you're looking for. Here is a link with pics to give you a better idea. The jury is still out for me as to whether it helps or not. Some say it does, some say it doesn't.

http://www.fordf150.net/howto/airintake.htm

 

Thanks, Tiron!
I wondered why that oval piece was so big compared to the small orifice running through it, I thought it had something to do with keeping the air cool.
Oh well, back to the drawing board.

 

Damn! They're moving their "server". Can't access the link!!!

I think I understand what you're talking about... that the 90 degree bend has a rather large diameter on the outside but only a 2.5 or 3 inch diameter inside. I thought the extra plastic on the outside was for strength because it takes up vibration between the body mount air filter and the vibrating motor.

 

!!!!!!! CAUTION !!!!!!!!!

do NOT remove the positive side of your battery first. Remove the NEGATIVE SIDE FIRST then the postitive side.

 

After looking at the weblink that Tiron posted it doesn't seem to make much sense to bother with that mod. It might sound nicer but actually lower performance.

While the piece inside the larger plastic 90 degree bend assembly may be slightly smaller diameter it probably isn't any smaller in diameter than the bore of the throttle body. Removing that piece probably slows the air velocity in that 90 degree bend section and creates unwanted turbulence.

I think if I attempted a performance improvement on that part I would try to find a mandrel-bent piece of metal tubing or plastic having a larger diameter than the OE silencer tube. Use those rubber pipe-matching hose clamp setups to seal it to the throttle body on one end (or the rubber adapter just before the TB) and the airbox on the other end. You could probably slap something together for a few bucks v.s. an expensive FIPK kit.

If it's made out of metal a muffler shop can expand either end of the pipe to fit the larger airbox diameter output or if it's made from abs type plastic you could use a dremel and a sandpaper wheel to smooth pipe transitions/joints when sections change diameter.

The air temp sensor is probably mounted in that larger diameter accordion type section because of the inherent lower air velocity since it's a larger diameter.

Anyone have further suggestions?