I went and made myself a $5 heat shield for my CTA intake. I used foam-core for the material. For those of you who may not know what foam-core is: it's a quarter inch thick sheet of styrofoam with a papery outer layer glued to each surface. It's sold in art&craft supply places, and it's very light and fairly stiff. It can be readily whittled into various shapes with a sharp knife.
The main piece of foam-core fits in a plane behind the back of the CTA intake's cone filter, going between the battery and the fusebox. The first step is to get all the plastic out of the wheelwell air opening. (This required temporarily loosening the CTA filter to get it out of the way.) The second step may not apply to many Contours: in my case the CTA's filter doesn't get all that close to the fender wall, so I had to loosen the battery clamp and inch the battery away from the fender.
Then, I cut a roughly triangular chunk of foam-core big enough to fit the desired space, and measured roughly from one end where the hole for the intake pipe should be -- making sure to leave extra width both above and below the hole. I cut the hole, big enough to go around where the rubber base of the filter fits onto the MAF sensor. I cut a vertical line below one side of the hole, and scored a line below the opposite edge, so that the section below the hole could hinge like a door, enabling the pipe to get to its proper position without an extra-dimensional shunt apparatus being required.
Then, with the door piece hinged open, I fitted the piece down onto the pipe, and began trimming the bottom end to fit the existing shape of the car body in the corresponding area. By successive stages I got it fitted down into place, with minimal air gaps around the bottom edges. Here it is at an early stage of the bottom edge fitting process:
You can see the hinged piece sticking out between the battery and the MAF. It kind of tore partially loose, and I realized I should have unplugged the MAF's wire connector before jamming it in there. I reinforced the hinge with tape.
Twenty or thirty minutes later, the bottom edge fitting is complete:
This lets you see how it's fitted closely around things like the battery tray and wire bundles and so on.
The next stage is to trim the top edge until it fits the hood when it's closed. Again, it's a matter of progressing by gradual increments. The result:
Finally, I turned the thin end at a right angle, and taped a scrap onto the end to fill in the last gap, and re-trimmed the top edge to fit the hood:
... and the shield was finished. Here is the final shape of the entire piece, out of the car, with a ruler for reference.
Performance gains? None observed yet. I think my engine is going slightly wrong somehow. The mileage is getting worse and worse -- my last tank was 17 in the city, where it used to be 20 or a hair less -- and the performance seems to be just a hair worse every time I try to measure it. I'll post something in Problems once I make a measurement or two... I know that Terry recently told someone to check the voltages on the O2 sensors.
