10\18\03 update I bought a new toy. I�m now going to switch from fiberglass to plastic. Since I bought a plastic welder it will be a hell of a lot less work ... Show moreto make it out of plastic. I may or may not finish the fiberglass one. So read below !!Why do this! Well so far the air kit I have is a waste of money. Yeah the motor breaths better but its all hot under hood air, not good for performance. I have been monitoring the incoming air temp and have seen temps as high as 130 degrees. My next issue is no one makes a nice cold air kit especially in no way shape or form for the 3.9l (yes you can use the 5.2 or 5.9 air kits). And lastly every other kit makes noise and if you want a cold air ram its visible. Well here is my plan. #1 thing this is stock looking and keeps with the sleeper image. #2 this would be a true cold air ram that will pull air from the high-pressure area on the front end. Lastly after looking at my air kit and stock air box there is not much difference in inlet and outlet sizes. Bill of materials Plastic welder kit $190(You could use a good soldering iron and fiber flex rods from urethane Supply Company)Air vents from a vw a2 or mk2 I got them for free I'm sure you can do the same Sand paper no idea had that hanging around toThat�s it so farFirst we start with fixing the oops. Make sure you properly store your stock parts! I dropped my stock air box and cracked the out let tube. But quick fix with the plastic welder Next here is a look at what the left and right heater vents look like normally they have these socks on them just rip it off no big deal.Next I started to make the inlet cone. Which is more or less and oblong opening. I did so by taking 2 of the vents and cutting the tip off of one and about half the other.After welding the 2 together you can see that I'm basically doing the same thing as the fiberglass but with plasticNext I took the stock lower half of the air box and popped it back in to see how it fit. My msd5 is in the way, and I'm not relocating it, so after a bit of adjustment the stock air box popped back in.After popping the lower half of the air box in, I noted that the snorkel does not sit as far away as I thought. So I changed my design. Rather then use an oblong opening I will now use just a round tube. So if you decide to go this route get 3 drivers side air vents from an a2 VW. I then took the stock snorkel and marked off where the 2 would meet. Cut out the hole. And then cut and trimmed one end of the vent pipe that had a curve on it. In the pictures below you can see that the curve directs the air at the opening of the air box it does not block off the stock snorkel. Why did I do this? I did this so that if that front tube ever gets blocked the motor can pull air from the stock location. A good example of this is when I drove through a puddle that was a foot and a half deep. With out my front flap water hit my air kit and my truck almost stalled! not good when your pretty deep into a puddle.Next was the snorkel extension that will act as the air ram. I started by taking the piece I cut the corner off and cutting that then adding another section on to it to make sure it was long enough. The flexible sections of these vents fit between the ac condenser line real tight and the ribbed flexible parts are just flexible enough to make it bend and connect to the air box snorkel. Next I made the airfoil out of a vw vacuum tank again from and vw a2 or mk2. It�s in the engine compartment on the driver�s side up near the headlight. I drilled a hole then cut the end off the tank. Now on my extension tube I left 1 full rib of the flexible part. This will help the airfoil line up. At this time I also test fitted the extension into the truck and marked where I need to cut my rubber flap. Once I took the tube back out I used the 1 rib on the end of the tube to draw my circle. Now I have cut the vw vacuum tank and have the piece that will be my airfoil. I used a file and rounded all the edges and shaped the inside so it made a perfect cone. It was then sanded with 80 grit sand paper to smooth it out, and welded onto the extension tube. now the kit is complete I will go back later on and sand it all smooth and paint it maybe the color of the truck. For now it will server its purpose for testing. I took the air box back out. Replaced the piece of foam that was on the side that I reshaped, and I put it back in. notice that when its all together the air foil sits perfectly right between the openings of the grill. Also take note it is not really visible. I took 1 picture of it with no flash just to show you that and another with flash so you can see how it sits. At idle you can feel the suction of the air into the tube, and when blocked the stock snorkel still functions.So far the kit works the bomb. We had a nice nasty rainy day. I drove through any large body of water I could find. This included the same puddle that I would have the stalling and hesitation issue. The truck trudged through with out a whimper or a wheeze. I took some pics of the top of the air box with water all over it. I also took a pic of the interior of the box you can see that there is some water in it but the filter was dry as a bone. I noted nice smooth acceleration with this kit. Engine noise is lower. Throttle response is much better. Check back as I will be posting more data on how well it works! Show Less
well since I've made cai out of plastic I may or may not finish this one so I'm leaving the pics up so that others may use my idea.
Why do this! We... Show morell so far the air kit I have is a waste of money. Yeah the motor breaths better but its all hot under hood air, not good for performance. I have been monitoring the incoming air temp and have seen temps as high as 130 degrees. My next issue is no one makes a nice cold air kit especially in no way shape or form for the 3.9l (yes you can use the 5.2 or 5.9 air kits). And lastly every other kit makes noise and if you want a cold air ram its visible. Well here is my plan. #1 thing this is stock looking and keeps with the sleeper image. #2 this would be a true cold air ram that will pull air from the high-pressure area on the front end. Lastly after looking at my air kit and stock air box there is not much difference in inlet and outlet sizes.
First you will need some supplies
1. Masking tape in 2 sizes wide and thin you can get the cheap kind but it does not work as well -->$5
2. Wire form. You can get it at craft stores it�s a wire mesh that is used with clay to make statues -->$20
3. Wd40 -->$2
4. Paintbrushes you can get the cheap kind I got 10 of them for -->$5
5. Fiberglass matt and weave -->$10
6. Fiberglass resin -->$5
7. Sand paper multi grits -->$5
8. Paint satin black -->$3
9. Stock air box -->free
10. K&n air filter for stock box -->$50
Now we get to the nitty gritty
Start by removing the rubber flap in the front on the left side of the radiator
Next take the rubber flap and using a hunk of the wire form, mold it into the shape of the rubber flap. This will make it ridged for the molding process
Now take your stock air box and pop off the air snorkel. using the wire form mold it on the end of the snorkel that goes into the air box. Make sure to over lap the wire form and leave the extra do not cut it off
Create a large oblong cylinder with a funnel at the top. Make sue that the cylinder fits between the ac condenser lines.
Using the masking tape. Place a layer of tape over the surface of the wire form on the air scoop and the flap
Now take the air snorkel and carefully remove the wire form make sure to mark off the free edge of the wire form stops. After removing it from the snorkel, trim the wire form back a bit to make the mold you just made a little smaller. Check its size by carefully inserting it into the stock air box. Do not put it in all the way. Now mask it with tape. Make sure to nock down the lock nubs on the wire mold or else it will be a very very hard fit.
Next spray wd40 lightly coat the taped parts. Mix up some resin and coat all the parts thickly with resin. Let them sit a few minutes and cut up the fiberglass matting. Place the matting on the parts and again coat it with resin you will be able to tell when the fiberglass has absorbed the resin as it will change color. Again let the parts sit a minute and continue adding another layer of fiberglass again coating it with resin when done just let the parts dry for a day.
After removing the mold and tape let the parts dry a bit more I found some of the internals were a bit tacky. Next comes initial shaping this is where the inlet cone and the front flap will be shaped and then placed together so they can be further molded with fiberglass. Show Less