Homemade Cold Air Induction
Making a homemade cold air induction is pretty easy. I have made quite a few for my own vehicles and customers alike. What I have always done is just go to the local hardware store and get the following parts:
3 inch PVC pipe (around 3' long)
45° angled elbows
two 3 inch rubber hoses
4 clamps
PVC cement
If you have have an 87-93 Mustang, you will have it pretty easy from here on. If you have 94-95 Mustang, you will need to use a Mass air meter from a 87-93 Mustang, but I haven't found this to be a problem yet since almost everyone is already running an aftermarket mass air meter with a conical K&N filter. Remove the old airbox (if you still have one) as well as the intake hose and the MAF. You will then want to measure the distance from the throttle body to the fenderwell so you can cut down the PVC pipe. The PVC pipe will generally be around 20 inches, plus the 45° elbow (that is if you are not planning on running it into the fender). Test try everything before you glue any parts. Now you will need to reinforce 2 spots on the pipe, the TB side and sensor locations. To do this cut both ends of the 2nd elbow, you will then have two "rings", glue the first ring to the end of the pipe. The second ring you should cut open on the side, add the glue to both ring and pipe and place it 3" inches after the first one. Drill 2 holes, one for the crankcase ventilation and the other for the Air Charge Temperature sensor (ACT/IAT). To connect the Crankcase ventilation we use a copper hose connector and a 1" clamp we found at the plumbing section. The ACT sensor is installed in the second hole, make the hole big enough for the sensor to screw into the pipe, enlarge it a bit at a time so the sensor is held tightly in place. After this step, sand the Cold air pipe. It's very important to sand since the paint might not stick to it. Now the difficult part, making the MAF ADAPTER. Here you have several choices, one would be to use a 3" to 3" rubber tubing that you can get in the RV section of any harware store. Simply hook one end to your mass air meter and the other end to your Conical K&N airfilter. Now that you have your mock up finished, go ahead and paint the tubing any color you want. If you want your airfilter to be in the fenderwell (this is the preferred method), you may need to do a little cutting of the sheet metal. It all kind of depends on the size of your filter. I was using one of K&N's largest filters so I had to trim back quite a bit but when using the smaller filters, the filter usually will just slip through the existing hole. You will need to use a 45° elbow for this or plan it ahead to where it angles perfectly into the fender. If you are doing this on a 87-93 Mustang (or a 94-95 with an 87-93 upper intake), you will need another 45° elbow to hook it up from the throttle body to the PVC pipe. Once you get everything put togeather it should all look pretty nice and will feel quite a bit quicker in the upper RPM range... Plus you will have a small hiss coming from the engine bay if you are using a large fenderwell mounted filter (some love this and others hate it, kind of depends of if you like the hiss of a supercharger... mine was that loud). I know these instructions aren't the greatest, but use your imagination and you will figure out what I am talking about. This is one of those things that is easier to show someone how to do it then it is to tell them, but its not really that hard.