Also..IMO..which means nothing, with the difusers, you have 2, basically wind blockers, that are basically hitting the air straight on, except for the actual difuser part, that puts the air into the fender. The square inches, of both difusers, arent enough, IMO, to slow a 500-600 hp vehicle down that much, if any, its minimal IMO. I'm not an aerodynamicist, wont pretend to be. Im sure the guys at Dodge did copius hrs of drag and inertia tests before coming up with this final product. But, IMO, instead of the frontal air, hitting the 2 difusers straight on, which IMO, is the same as hitting the firewall, then, to me, the parachute effect would be minimal. Plus, maybe like this, some of the engine heat, is being diverted to underneath the truck. We would need a wind tunnel to figure this out. In the mean time, I'll just leave it this way. Wrong or right. Thnx for your comments. I'm not saying your wrong by any means, you might be spot on. This is just my thinking, and it works for me..!
Talking diffusers (grill block off's) and Ram / Cold Air feed.... Grill block off's first.... Think NASCAR just for starters. When the playing field is virtually equal other than driver, pit stops and suspension set up, on the super speedways, the teams determine how small of an opening thru the grill is need to maintain enough cooling to finish without overheating. You may notice that they ADD tape as the race goes on. This assists aero and speed. As you know, the NASCAR truck team assisted in the development of the aero's on our trucks. Frontal area is our biggest speed enemy. Here is an excellent quote from attached article link..
http://www.edmunds.com/fuel-economy/improving-aerodynamics-to-boost-fuel-economy.html
"Cars typically have a much lower Cd than pickups and SUVs, which sit higher, are bigger and have greater cooling needs. Cooling is a big deal, aerodynamically speaking, since it requires airflow into the vehicle through the radiator, which increases drag."
"to reduce drag. "We look at all areas of the car that come in contact with the air. Upper surface shape, under floor, wheels and even cooling and engine bay,""
With that being true, the engineers determined the smallest opening required to cool the big 'ol V10. Smaller opening moves the maximum amount of air AROUND or trucks... not through them. As a bonus to us, the passenger block off has a VERY effective scoop to catch a slice of the high velocity, cool air and funnel it into the fender cavity. I'll touch on the benefits of that in a moment.
The next benefit of the smaller grill opening is "Diffusion Cooling". Our trucks cool better when the air coming into the engine bay SLOWS DOWN, thus absorbing more heat over time and then exits out hood vent (scoop) and below firewall. Remember, the hood "scoop" is actually in a low pressure area and is under draw.
The same dynamics come into play with our factory "Cold Air" feed. Just used for a different benefit. That slice of high velocity, cool air SLOWS DOWN as it enters the fender cavity. This is where the basics of "Ram Recovery" occur. As the air slows, volume increases as does pressure. One primary RULE of ram recovery is the opening needs to be SMALLER than the duct (which gradually increases in size) as it enters the "Air Box" (our fender) allowing the high velocity air to slow down recovering pressure and volume. Now, as our engine needs to, it draws from that cavity on every intake pulse. The beauty is it's not drawing from a static environment! Also notice that our oil cooler benefit's from the same cavity. There is such a high volume of air in the fender at road speeds (above 40 mph) that there is more than enough for both the engine draw AND the flow thru our oil coolers. So much so that the cavity does not need to be completely sealed.
As for "Parachute Effect", not only is the added "drag" a drag, the front end lift can negatively effect handling and grip.
So, after all that, you can see how two simple pieces of black plastic have a HUGE effect on overall truck performance. COOL HEY?
Cheers!
