That is the same thing I did to mine last year. It took my mpgs up by 1.5. I used a 3" hole saw and made two holes that just touched each other and then used a cut off wheel to connect them top and bottom. I have driven in some pretty serious down pours and never had a problem. Also with the style cowl you have (all the small pin holes) snow will not be a problem either. The truck can still breath thru the drain holes on each side. If you loo at them they are real large. I am going to do this mod on the 81 body when it goes on next month as well.

 

The snow problem is not because the hole gets covered.

What happens is the snow get sucked into the air cleaner, then coats the filter with ice.

When you get enough ice, the engine stops from lack of air.

If that happens, you better hope you have enough heat left in the cab to melt the ice off the filter or you have to start the engine with no filter to get more heat to melt it clean.

When snow is falling or blowing across the road, my ram air gets unhooked right now.

 

well that didn't last long guys lol.
i went up the mountain yesterday and when she hit 2nd i was rolling coal.

i popped the hood and saw it broke off and sucked itself closed from being pinched over the brake master cylinder.
so i tossed in the short plastic stock section over the master cylinder and sort of cleaned up the end of the dryer duct and stuck it inside that.
i got all my power back.

i ordered that plastic duct off e-bay i linked to earlier,just now.

 

still waiting for that new duct,but i just went through my wood chipper maintenance and have that going again,now that i have my rig pretty much back to tip top and converted over into a dually dumping tree service 4wd machine.
i will get some paint and dress up soon,but for now the chipper is needed.sick of hauling brush.

well, iv pulled the chipper to a few jobs here and there in the past.well i hauled her today,and gave her a nice load.enough to know the duals where required
im going to use the word: "massive" for the difference of stock vs cowl induction while hauling.
it may not amount to much without a free flowing custom exhaust.but she has more grunt and it's much more easier to try and get closer to being able to maintain speed up/down hills.she still asks for 2nd gear on the big ones of course,but once she hits 2nd and revs up to 3k+ it has WAY more than it did.i can feel the increase at all speeds,with the biggest increase being at high revs.she's loving this stuff.
can't wait to dual cowl injection her,and maybe turn her fuel up until i just barley start seeing a little light gray haze.no pryo yet,so i don't want to risk much.but i know she would like a bit more juice now too.

i know,people all over this site tell us that diesels love air.
i wish i listened to that closer and did this before.the difference is easily felt.

oh yeah,i almost forgot.
i normally take off nice and easy you know,for max economy.
well since i was all loaded up and had the chipper (pretty much to my standard max level combined.) i had to play doncha' know.
well i gave her some juice just outside the city i was working in today.she'll get up and move faster than i ever normally take off empty x4 lol.

oh yeah,another thing before i forget.it's not just a big increase at high revs.
just loaded up nice like i was without pulling the 2k lb chipper i hit some good grades where i normally saw 2nd gear without question,she climbed up with the iron to the floor in 3rd! every one of those times i was like WHAT!
massive difference guys.exhaust alone isn't enough.she needs to breath in and out free.

 

I'm interested in this mod for my truck, but I have a concern or two being my location.
I live in British Columbia, and well it rains on and off here like 9 months out of the year, and we've been known to get a good chunk of snow.
From what I've gathered taking it off for snow is a given, and that a little rain wont hurt. But I just got back from a camping trip where it rained heavy for 3 days straight, would this even be a feasible modification for someone in my climate?

 

have you ever replaced your wiper motor and had to remove the cowl to put the arm on - i just had to do that lol.
it rained the next day or two after i did this mod,and saw my motor was having a hard time/sounded real bad too.
well i wish i knew that first,it would of been easier to do the mod.though not by much though i guess.
well if you look down in there with a drop light/flash light whatever,you'll see its VERY deep.
run a garden hose down your cowl and try to fill it.you'll notice even with this much water,you could never get the level up high enough to where the hole would be to clear the master cylinder.
the water drains out the side drain very quickly.
there's no way i could see rain water being an issue whatsoever.
with the ram air mod,you would likely pick up more rain water into your ducting because your driving straight into it.
i would have to say if anything, cowl induction is safer against rain than ram air.

 

If he is thinking like I am,when the engine is running it sucks air like a vacum cleaner...You sure it wont suck the water/mist in ? Especially at higher RPMs?

 

That is exactly what I was thinking, we had rain so bad that it fried the fuse box on the family F150, and that was with the hood closed, and the rubber weather seal in place.

 

im thinking of running mine behind the overflow tank on the drivers side of the brake booster. just wondering how i can get some good fresh air in without bringing in tons of water with it. and i DO NOT want to throw on those terrible f250/f350 from the 08+ bodies. shame they are so ugly cause it would work real nice

 

Are you referring to the cross pattern holes under the F250/350 decals like this one?

 

here we go.my duct came from ebay today so i put it on.
this is much better.she won't be coming undone anymore.
Project Cowl Induction: complete,and loving it!

i got all my wire loom on there too see.
that looks better.now i need to grab some black engine paint and paint my air cleaner.need a new hood weather stripping there too.that's why it's rusty.

theres my new wiper motor i put in last week or so.boy does that work better/faster/quieter.

oh yeah,see my electric line is unhooked to the master.that's because my truck wasn't on the road when they recalled it.i need to call ford to see if they're still doing it or just put my own inline fuse in and call it good.
its unhooked for now,so she doesn't burn to the ground.

 

looks great man now thats one more upgrade complete and youre pry already on to the next one!

 

I've been thinking of adding some kind of cold air feed and cowl looks a good location - a lot easier to cut in than ram air, although less pressure. I'm wondering if anyone has tested whether there is a practical limit to how much air is actually usable by the turbo motor. What I'm thinking is cutting a 4" cowl hole on each side of the motor, permanently attaching a flange, hard piping it to a "Y" and then a rubber coupler to the stock air box. Will the motor appreciate extra pressure or is this overkill? Otherwise I'll just do single run. I found some cool parts in case others are interested.

I'm thinking of this flange:
4" Intake Duct Mounting Plate Cold Air Tubing Ram Tube: eBay Motors (item 170294502400 end time Sep-06-10 15:23:07 PDT)

And then a bunch of hard piping from intakehoses.com.

 

actually,did you know the grill is not a high pressure area at all?
(there's more to it than simply driving into the wind so to speak)
some studies claim that ram air setups on street cars are to no benefit,because the advantages of ram air are not seen until 100 mph.
where as cowl induction is a high pressure area,and the benefits are seen over ram air starting at 35 mph (of course this greatly depends on the vehicle.our trucks with steep windshields however are likely even sooner than 35 mph)

the more cool,pressurized air you can get into the engine,the more you could turn the fuel up.
If you have a boost gauge,it would be interesting (and appreciated by many) if you could compare boost readings as stock,cowl,and dual cowl induction.
one has to think,the more pressurized air you could start with,the quicker the spool time of the turbo would be i should think?

i was thinking of using that adapter too (i got my duct from them.) but having a round intake on my n/a i would have to just seal it up with some silicone i guess.
on the turbo intakes,you have a flat surface to mount it too,so no issues.

 

Nice work, chances are I will do that to my 86 instead of spending the cash on a hypermax again.