I can't believe this was made, but it has been so I will now explain something AGAIN. As if the coolant bypass myth wasn't enough, we seem to have found our source for ignorance.


This heat shield mounts under the throttlebody, in an attempt to block the heat from the exhaust manifold crossover. However, we must first question the reasoning for such a device. What makes people think the TB is the source of evil and worthy to keep as cool as possible? I think it has more to do with the ease of install and production to make a quick buck than anything beneficial to the engine.


The air moving into the engine starts somewhere, and that place is USUALLY in the engine bay. Right there, you have warm air. At idle, that temp is going up because there is no circulation in the engine bay. Once you start moving, the engine bay gets fresh air, and starts to cool off. The throttlebody by then has also absorbed heat from the intake manifolds, who have got their heat from the heads and what is radiated from the block. I have to assume with the heat shield, you won't have the coolant lines going to it.


The smart thing to do is find a cooler source of air for the intake. For this, we look at a cold air intake. With this setup, your idle temps will increase still, but nothing like before because you only have the heat radiated through the fender well or the street or just stagnant air from wherever you mounted that bad boy. While driving, its instantly cool.


Now for the heatshield. What good does it do at idle? None. But we don't race at idle, and again I have to assume the everyday driver doesn't give a crap about his TB temp, or what it supposedly does for anything. So lets enter race mode. With the stock intake suckin up warm air, your TB is going to be warm to hot because the air going through it will not be a considerable temp difference to cool it off. That is right, the air moving through the TB will dictate its temp, not deflecting the directly radiated heat from the manifolds while ignoring the radiated heat off the bottom side of the hood, and the rest of the engine bay.


With the cold air intake, you will start to cool the throttlebody off as soon as you start racing. You will also be cooling the intake manifolds and the intake port of the head. The temp of the air however isn't going to be changed much because of its high velocity. Its the wind chill effect for your engine.


Now, of course, there will be SOME raise in temp, because it has to travel through the hot TB, hot plenum, hot lower intake, and the hot head. Given the surface area of each item, can you guess which has the least impact on the air temp? Thats right Einstein, the TB has the least effect.


So, what is the big deal with all these throttlebody mods? Its simple, people like cheap bolt ons, especially when they are new to cars and don't know that cheap and performance RARELY go together. Its easy for a company to make a profit on it, and making the product sound useful without lying is a cinch.