I have the Mazdaspeed Axle-back sport exhaust...and quite frankly it didn't do much either. If it was a cat back, I guess it would be a different story. Oh well. The 1.6 isn't known for it's moddability.

I've run the car w/ and w/o the plastic piece...no difference. I'll just leave it in there for now, I'm too lazy to take it out.

 

HMMMMM very interesting, ill give you credit for the testing, and the creativity.

 

Caretaker, a friend of mine has been thinking about doing something similar to what you have done. What materials did you use to make that, and what did you use to insulate the top?

By the way, if you can, insulate the inside of the "Box," because that material will not only reflect heat, but will carry some of it inside.

If you have ever peek into a German car, you'll see that their heat-reflecting material is backed with insulation.

 

For the aluminium panel, I bought them at a 1$ shop. They are easy to bend. Be careful though not the buy the thinnest one. The 1st type I tried was too thin and cracked because of the pressure during the aspiration.

For the insulated material, I used a material used to make bags to keep food cold. Here are the properties (Temp vs time):



I know what you mean with the material your talking about in German cars. I have seen them at Autobacs here. Not cheap! 50$ per sp. meter.

If your friend did not buy anything yet, the Ingen intake concept is simpler and more good looking though.

 

I live in Florida and drive a lot of back roads where flooding is a problem. I have the Injen CAI with the splash guard that I mounted to the underside of the fender well. I cut the pipe and mounted the filter so that the hose clamp is inside the engine compartment but the filter is still in the fender. It raised the filter about 6" and makes removal and install much easier for cleaning. I think the car would float before the filter goes under now.