capt.Ron

Ok guys, here's my delima.
I bought the wife a new Challenger for her birthday and I want to give it a little more umph!!
I've cruised the challenger and Charger forums and all of the cold air intakes are way too high for what you get, plus what we've figured out is that because they are not closed systems the air temp on these intakes are higher than the temp of the stock intake. I want to make a mold that will hold the biggest cartridge filter that Amsoil sells.
My plan is to pour some type of expandable foam into the compartment where the current airbox sits. then when it hardens pull that block of foam and use it as a form. There is a 3.75" hole in the bottom of this area that the current box breathes from. The front left corner of this area is a massive opening. I think I can incorporate a snorkel off of the new box to feed into that opening to allow more air.
My delima is 2 fold I've never worked with this foam or fiberglass for that matter.
Anyone out there with experience in these fields??? I sure could use some help here.
There's lots of odd angles so just building a box would be cumbersome. I thought I might use some light plywood or maybe even cardboard for the sides, put a large plastic bag in there and pour the foam. When it hardens I can lift it out flip it over, put a release agent on it and cover it with fiberglass or even carbon fiber. When it sets pull it off, clean it up and there's my airbox.
I need help with specifics so I don't screw up the engine bay of the Challenger.

t-boe

Will this work?
http://www.wonderhowto.com/how-to/vi...s-mold-259755/

This should help too for rubber elbows and such.
http://store.airflo.com/

aborgardt

use a thick plastic, like a contractor trash bag or even some 7 mil plastic, and press it into the filter box. Use great foam as your foaming agent. but dont try to fill it all at once cause it will not expand right. do it in stages, spray some in there and place more plastic over it and put a brick or something on the plastic. this will help to force the foam to stay at the lower end of the box. when you get close to the top of the box spray some foam into it and put more plastic over the top and place the lid on. There is our mold. when you build the box just use the thick plastic as your 'release agent' since fiberglass will not stock to it. Just keep the fiberglass resin away from the paint. that stuff is nasty (learned the hard way). Have fun....

capt.Ron

Yea the heavy mil plastic was what I was thinking but was unsure if it would hold up from the chemicals in foam.
Also I was not going to be using the stock box for the mold but rather the space that it sits in. I'll need to create rigid walls around the area to keep things square.
How thick should I make each layer? (before expansion)
The total volume should be around 960 cubic inches. One can should do that????

Sidewinder

If you go to a good fiberglass supply place they will probably have the correct expanding foam for that type of project. It seems to expand better (filling in ALL of the spaces in the mold) but it does not expand with the same force as the stuff used for insulation that you get at the home supply place. You mix two chemicals together and pour it into the "mold". Of course you will still need to line it with plactic first.

aborgardt

dont worry about the chemicals.... I would do a few inches at a time. Keep in mind also you dont have to put so much time into making walls. the foam cuts fairly well.

I think one can should do that much, but you will need to clean the tip between layers since whats in the tube will cure at the same rate as what is not in the tube.

capt.Ron

Clean it with acetone or mineral spirits??

AlpineRAM

We usually did build these things a little differently- Take some plates of styrofoam and glue them together to get a block approaching the airbox we desired, then cut it to size or glue some smaller parts on and do fitting tests.
When it fits with the right clearance to apply the fiberglass we would put some styrofoam paint on to seal the surface, then start to laminate the fiberglass.
After that a beaker or two of regular gasoline does away with the styrofoam, now you have your empty airbox, no risk of spilling anything in the engine compartment, a smooth finish on the inside of the airbox, and some nice and clean edges if you desire them. The foam method usually takes a lot longer and with the plastic foil you have wrinkles that do ruin your finish .
Just my 2c

AlpineRAM

aborgardt

Well put!!! This is the method i prefer as well. I used the green foam you might use for a floral arrangement. Worked well...... As for cleening the straw if you choose to go the route. Yes, acetone should work. I beleive the can tells you what to use for cleanup.

capt.Ron

Hmmmm that does sound much safer.
Now what if I want to keep the block as a pattern to make more boxes? If I just apply a release agent to the block it should separate off shouldn't it?

AlpineRAM

The block is inside the laminated box- so you need to either make your laminate in 2 parts with a plane of separation (You can use some very stiff plastic that protrudes from the model to get a nice sealing surface) or you form some outside negative that is splitable from your first model, clean it up and have a nice form for a small series with a good outside finish.
Another way if you want to do bigger numbers and want to get a clean inside (that's what I prefer) is to build the block from plates of styrofoam, make a thin plywood contour of it and number them according to the plane it is on- then you can make the styrofoam parts really quick. If you make 2 holes into each styrofoam part so that you can use bolts to put them into correct relative positions and drill those holes into the plywood matrices too, you are set for quick "mass" production.
The technique I described is really nice because you can make shapes where you are not able to extract the core in one piece.
Since the outside is not too nice if you laminate the part, you cen use some roll-on or spray-on neoprene that gives you a nice finish and has excellent acoustic properties- and it does also reduce vibrations of the part that will lead to breaking.

HTH

AlpineRAM

Redleg

Maybe you can get this to work? Scroll down.
http://www.yearone.com/serverfiles/f...?hid=120AA5138

capt.Ron

Not doing a hood scoop.
I'm actually just building the airbox and will snorkel it away from the engine bay. Not going to try for RAM air. Don't want to chance water in the intake.