What is this suppose to achieve? I have some high heat insulation hanging around, so what’s the benefit here?
I always change the oil with the engine hot, and on a past occasion I noted how hot the intake components get. Try it. After a drive, pop the hood and feel the intake hose and the plenum. Since hot intake components must heat the intake air, hot air has expanded and is less dense (which is why hot air rises), and thinner air has less oxygen by volume, I got to thinking about what that means and what to do to remedy it. It seems to me that in order to maintain the proper stoichiometric fuel-air mixture, less fuel would have to be injected the hotter the intake air becomes. That means less power, and it may be why Ford put the vents in the hood and fenders. The intake components get hot regardless. The close proximity to the hot engine assures that.
So I found those insulating products at
www.designengineering.com and gave them a try. The Reflect-A-Cool product is silver and works well on flat surfaces. I think it's a bit too stiff to adhere for long around a tight radius. The Reflect-A-Gold product is more expensive, insulates 17% better than the silver stuff according to the company, and is way better to work with on curved surfaces. I used the gold stuff on curved surfaces and in locations closest to the radiant heat of the engine, and used the less expensive silver stuff on flat surfaces and in locations that don't get direct radiant heat from the engine. Both products continue to adhere and stay where I put them. Design Engineering's product descriptions specifically mention the use of those products on air boxes.
Has it made a difference? Hell, I don't know. I don't own a dyno! But it stands to reason that when the engine is hot there will be more power available at wide open throttle because a denser fuel-air mixture will be delivered to the cylinders. It won't affect fuel economy, I'm sure, but it might be a good thing for towing and heavy hauling - particularly in hot climates. I make no claims. It just seemed like a good thing to do.