I was looking at the grill of my 91 F150 the other day and noticed that the air induction tube leading from the grill to the airbox is rounded at the front. That means the air doesn't flow straight into the box from the grill but has to corner into the tube first. Some time ago someone on the list (Teo?) said they were going to cut this rounded part off so the air would flow directly into the tube and up into the box. I'm wondering if anyone has done this and if so what the results were????

Seems to be an easy modification if it helps. Thanks.

Guy

 

I wanted to run a third or fourth tank of gas to confirm with certainty that my increase of 1.5 MPG is valid b/4 I posted results of modifying the air intake system. Data may not be valid, however, as I also had the front-end aligned…one wheel was toed –0.67 and the other –0.27 degrees.

Two weekends ago I cut the tip off the intake channel and riveted on a duct the same size as the adjacent grill opening. I had the duct fabricated by a local HVAC shop that owed me a favor. Also, I covered the inlet with screen to keep the heavy stuff out (I need a scanner so I can post photos of this thing). Quite neat and tidy. And, my K&N drop-in filter gets a straight shot of cool mountain air.

Benefits are at the top-end at cruising speed. The difference in power is somewhat like the effect of turning off the AC. I feel certain I’m ramming the bore with a lot more air and believe the exercise was well worth the effort regardless of the variable mentioned above.

Teo

Bend, OR
92’ F150, 4x4, M5, 300 I6, 113K, standard cab & short box
97’ Fjord 850

 

Thanks for the post Teo. Looks like a mod worth doing. Does anybody know why Ford designed it the way they did?

Guy

 

Teo,

how do you prevent rain, snow or other moisture from entering the intake, saturating your air filter and possibly damaging the intake manifold or engine?

Adam

 

Have you seen any problems from the rain or snow Teo? I live in WI so the snow might be the big problem for me. Can the snow or rain really make it all the way to the filter?

Guy

 

on a bend area of the stock piping you will notice a hole, this is so moisture is forced out by the air coming in. Mount it high and like behind the headlight area. "Ram air" effect only works for high speed, so having a direct flow from the front isn't that important. I did this mod on my wife's Taurus and noticed more low end kick. I have it going directly outside the engine compartment thru the wall to the fender cavity where I cut it. Covered it with a nylon window screen and zip tie. Only took an hour on her car.

 

I have a 96 with 300/6 4x4 ext cab M5 and just took the whole snorkel off a few weeks ago. To me it seems like the intake in the snorkel is a little smaller than the intake in the filter box. Anyway at full throttle it bellows a little louder and feels a little more free reving. I'm still running a stock filter for now. I think the snorkels on most engines are to cut down on intake noise as much as anything else.
Chris...

 

Are you concerned at all with the higher air temperature if sucking it right from the engine compartment vs. from the outside? I thought that the cooler air somehow improved performance?

Guy

 

Cooler, moister air carries more oxygen, which is why you want to bring in outside air, or at least as far from the heat of the motor as possible.

Of course, it's all relative. The K&N FIPK kits that run an open element in the stock location suck hotter air, but the increased flow more than makes up for the temp difference. Of course, most of the added HP is at higher revs, so I'm not sure these kits help much with trucks.

Four Wheeler just did an article similar to this. They wrapped the snorkel and airbox all the way to the intake with reflective tape. It lowered the intake air temp a few degrees and resulted in a small HP gain and better mileage. No mention of them cutting the intake snorkel, though.

 

I also read the Project MPG article on wrapping the hoses and intake with tape - I found some Reflective heat sheilding tape at Lowe's Home Center for less than $10 and did the job...It increased my mileage - ready for this - by SLIGHTLY over 2 MPG! This was comparing 2 tankfuls on the same commute over 3 weeks...

You can go to my homepage at <a href="http://www.erols.com/sctate">http://www.erols.com/sctate</a> and scroll down to check out a pic of the work I am talking about!

=)
Steve

 

You know, I also thought about looking for some generic reflective tape. This after I priced the DEI tape at @ 1$ per ft. (Summit Racing).

Thanks Steve! Looks like I have a new weekend project...

 

Went to Lowes yesterday. Is this the aluminized tape for HVAC ducts? What was the product name? Just want to make sure I got the same thing.

Todd

 

I am on vacation at my parents...there is a Lowe's about a mile from their house, so I will make a point of stopping in and finding out what kind - what I know for sure is it is on the aisle where all the tapes are (amsking, duct, electrical, etc...) - at least at my hometown Lowe's all the tape is together - I also tried 2 sizes, and one of them was MUCH better - let me find that info out for you too, and the roll is at home and the cardboard insert is not labelled.

=)

I'll get you that information later today!
Steve

 

Finished wrapping my snorkel and airbox and re-installed it yesterday. I had trouble finding the tape at the HomeDepot close to where I work, so I stopped at another home center on the way home. I was looking for tape made for Reflectix insulation, which is a reflective insulation (looks like bubble wrap sandwiched between 2 sheets of foil). They make a tape to join the seams. It will usually be next to the rolls of Reflectix in the insulation section. This stuff looks like aluminum foil, and I have seen similar tapes in the duct work lanes.

Anyway, I lucked out. The place I stopped is closing, so I was able to find the Reflectix tape for $2 per roll (2"x30'). I bought 5 and used 4 plus a little off the 5th roll.

I covered the snorkel, airbox and tubes from the box to the intake, put in new filters and buttoned the whole thing up in my kitchen. My box had 2 small drain holes in the bottom, so I made sure to open those up again. Total time was about 3hrs, most of which was spent cleaning and applying the tape.

Can't say whether this will help much or not, as I haven't tracked mileage in a while. Then again, the total cost was less than $11 !!!

 

Steve, Was your mpg increase because of the tape or the JACOBS ignition? I just installed the Jacobs Omni Magnum and got 2mpg increase but i have not done the tape yet. Please let us know. The Jacobs ignition is the best item i have ever put on my 1996 F250 with a 460. Tim