WAI? thermostatic control valve, etc.

[MTUboi86]

Hello all.
About two weeks ago (i'm in school, so haven't had the time to look it up) I went out to my 1994 Ford Explorer (4.0L V6 Auto) to rig up a warm air intake (or hot air intake... not sure of the difference.

Well, I found the cold air intake, and looking at it from under the vehicle I followed it back to the air filter box to try and find a place to disconnect it (takes cold air from the front of the vehicle, between the front grill and headlight, not in the engine compartment). While looking, I discovered that the explorer already has an air intake tube running from the exhaust manifold to the air intake, in conjunction with the cold air intake.

I looked up info online, and apparently in these early engines, they used a thermostatic control valve to help control emissions. It basically uses a vacuum-powered switch when the engine is cold to take warm air in from near the exhaust ... but it switches back to only cold air once the engine is warmed up.

Well, at the time I was unaware of the thermostatic control valve, so I decided to get a small piece of cardboard to cover the cold intake portion.

Does anyone know if there's a way I can get this valve to stick so it only takes in warm air? This way I won't have to even purchase anything to have a WAI/HAI.

With the cold air intake blocked, I've noticed a ~2mpg improvement on highway driving (21.43mpg on a 25 mile hwy trip at 55mph). It's the first time I've gotten over 20mpg with this brick-on-wheels.

The cardboard will work good as a temporary block, but it's not a complete seal either, it's just kind of there, mostly reducing airflow.

Any ideas?

I plan on more mods for better FE for my 1,000-mile round trip from school back home for thanksgiving break, so other suggestions would be nice too. I already increased tire pressure to 40psi (max tire-wall 45psi) and have modified my driving style (still learning that though), and plan to take my roof-rack off soon. Would lowering the air dam help at all, or just increase surface area and therefore reduce gas mileage? The front of the explorer is completely flat, not the rounded front end that started in 1995.

Thanks in advance!