Ram air intake behind headlight

i just made a "custom ram air" mod for Rogue Pro5's car. Hopefully we'll have everything re-installed soon and I'll post pictures for you.
 
Ram air is certainly not a myth. Just as having a less restrictive intake yields increased power, having a greater density charge of air also leads to greater power. If you are driving at highway speed and hold a large funnel or scoop out the window while driving, with a 4" diameter (similar to an intake) pipe running from it into your car, the end of the pipe will blow like a leaf blower. There is no difference between this and mechanical forced induction (superchrgr or turbo), except that it works to a much lesser degree.

The vetteguru article is extremely poorly written and should raise question to its validity. It is true that many automakers use "ram air" as a marketing ploy to sell cars. A lot of the so-called ram-air setups are simply a CAI with cosmetic flair.
 
"To make matters worse, it is mathematically defined almost entirely by experimentally-determined mathematics. "

This is one of the stupidest sentences I have ever read. Any mathematical foundation must be experimentally determined. That is how theories are tested, revised, and proven.

"This last point is the true differentiator between those who only understand concepts, and those who can quantify what they are discussing. Truly, quantification is the real skill of the engineer. It is one thing to speak about qualitative issues (the what of the physical sciences); it is entirely another to quantify them (the how much and to what extent of the same). In grade school, students are first taught about closed form mathematics and then that these mathematics are typical of scientific expression. A good example of this is Newtons famed law of action and reaction, the mathematical expression of which is a succinct F=MA. So straightforward. So simple. Three variables in perfectly-defined harmony. Given any two of them, the third is easy to nail down. "

It is obvious that this guy is trying to sound smart, while making no point whatsoever.

"So the hot rodders adage more air = more power is proven correct. Figure out a way to stuff more air into the cylinder at any given RPM and throttle setting, and you can burn more fuel. Since burning fuel is what makes power, more air truly does create more power"

Right, this is why ram air works.

The basis for his argument is this...

"Below about Mach 0.5 (or about half the speed of sound), air is considered incompressible."

This is untrue. Why do toy styrofoam airplanes fly? Why do golfers put backspin on the dimpled golf balls to get more distance? Because of a difference in air density. Golf balls and toy planes don't go faster than Mach 0.5, but somehow the air under them is denser (compressed) than the air above them, creating lift.
 
how would feeding more clean cold air not help???

i have ractive SRi.. @ first it felt worse then the oem intake.. but after i put in the heat wrap and and 2 ducting tubes feeding cold air to the intake..

and all i can say is every little bit helps.. not sure behind the headlight would help.. but from under the car sure does... now all i need is to mold up something to look good under the engine bay hehehe
 
Behind the headlight helps especially if you're not running any weather stripping on the hood. The air passes more freely and it's colder. With my aem filter sitting behind the radiator..it was sucking in too much hot air. The car was getting bogged down on hot summer days. I moved the filter up behind the headlight..and the car felt more responsive.
 
Many of you are familiar with the Formula 1 car air intakes located above the driver's head and facing forward. Due to the high speed of these cars, air enters the intake at a very high velocity. However, to make effective use of ram air, the air velocity must be slowed down and converted to a static pressure. This is accomplished by employing a diverging duct behind the intake opening leading to the air box over the intake ports. Thus, by the time the air reaches the intake port, its velocity has been greatly slowed and converted to a static pressure. Since this process creates a denser air charge, a useful power increase is obtained through the ram effect as explained by jonlong.

However, even in a road car ram air can have beneficial effects on power output, although to a much lesser degree. At normal road speeds it's not likely that a positive pressure will be created in the intake system but a reduction in negative pressure is quite possible leading to an increase in intake air density with a consequent power increase.

For an explanation of how this works on road cars, check out:
www.clubprotege.com/forum/showthread.php?t=2921

Here you will find the mathematical basis for calculating ram air effect, an example of a homebuilt system with measured data demonstating its effectiveness and info on where on the car to locate air intakes to insure they are sited in a high pressure zone.

02 DX Millenium Red
 
jonlong said:
"To make matters worse, it is mathematically defined almost entirely by experimentally-determined mathematics. "

This is one of the stupidest sentences I have ever read. Any mathematical foundation must be experimentally determined. That is how theories are tested, revised, and proven.QUOTE]

What the guy is saying is that all the mathematical equations that define fluid flow are derived (we are talking differential equations here people) by using simplified mathematical equations to approximate what is actually happening. There are WAY too many variables to create exact laws that you can measure with precision. I work as a hydraulic engineer in case you were wondering.

That being said, I don't really know if ramair is a myth or not, in theory it should work but the benefits may be negligable.
 

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