I think you guys are pretty impressive with this thread. But hasn't all this research been done several times over by the engineers at every major automotive company anywhere in the world? Using more accurate equipment and methodologies than are available to you? We know, for a fact, that getting cooler air into the cylinder will provide more o2 to the combustion, creating a more forceful fuel burn. We know for a fact, that altitude works in the reverse way: there is less pressure at altitude, resulting in less O2 present in the volume of each cylinder full of air. Supercharging and Turbocharging are the only ways to gain a significant "ram-air" charge, which works because the air cannot escape and is being
forced into the cylinder under pressure.
I think enough research has been done to prove Fordum's point of turbulence playing a huge part in this, also. Which is one of two reasons why the "ram-air" idea doesn't produce the same numbers as does a supercharger. The turbulence of the air entering that tube in the front support is high, and depending on the configuration of the grill, there may actually be a pocket of lower pressure there. Push that air through a restrictive filter and through a corrugated, hot plastic pipe around a couple of 90* bends before dumping it into the throttle body and I think that air is about as turbulent as it comes. If I'm not mistaken, one of the claimed improvements of the Vortec motor was the airflow into the engine was somehow smoothed by the intake, which increased the pressure on each piston resulting in increased performance. Throttle body spacers and other devices to smooth air flow as it enters the throttle body/ intake manifold are a big chunk of the aftermarket industry.
It would seem what you're trying to do is verify whether or not changes the owner can make will bring about any significant change in HP or TQ numbers in real world applications. And I think you're going to find the difference to be barely measurable. Like trying to split a hair with an axe. That being said, I am reading and learning with every post, so please continue! (And remember, I set up the intake on my 5.7 just like you guys are talking about, so I obviously think your thinking is valid)I just think there are so many variables involved in this that the numbers aren't going to be as significant as you guys think. Here is why:
I once took a truck down and dyno'd it. It did much more poorly than I thought it would. We couldn't figure out why, until we got back home and realized the little door in the intake horn was rusted shut, allowing almost no air to enter the air cleaner assembly. Only what could get in around the cracks and the filter lid...and that would be hot, engine compartment air, so you would think the numbers would be way higher with that obstacle removed. Removed that little door completely and reran the dyno. It had gone from 111 hp and 185 ft. lbs. at 4050 rpm to 128 hp and 197 ft. lbs. at 3898 rpm. So my prediction is that the engine is getting all the air it needs without all the fancy piping. Will it help, yes. Will you feel it, probably not.
What's impressive to me is the reasoning, the scientific thinking, and the ability to formulate and test a hypothesis that I'm seeing. It's something that has largely been lost to video games and facebook. Maybe I'm officially old, but I don't think many college graduates these days could even understand what this thread is about!
