2007 Nissan Frontier front grill

[Kestrel]

Hey guys, I'm not too familiar with how much air needs to feed through the grill and lower bumper. I wanted to start covering parts up and was asking if someone can let me know where I might start. Also, I have the honeycomb grill plastic and wanted to know if I cover inside, or cover outside to make it flat. I know the mirrors are out and big, that will fix will come.

Here's a pic, I also want to lower the bottom bumper by making a skirt and wanted to know about how long it should be? Any help would be greatly appreciated.

[aerohead]

I'm gonna try a link to Walter Korff's cooling system schematic
Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - aerohead's Album: Book illustrations - Picture
Here is the internal architecture of a diverging duct.If the walls curve too steeply,you have internal flow separation.
http://ecomodder.com/forum/member-ae...tbody-car.html
Here is Hucho's table for 'optimum' noses.http://ecomodder.com/forum/member-ae...iguration.html
If you'll compare the Nissan's nose,you'll get a feel for how to proceed.Your inlet can be only a fraction of the height of your radiator if your inlet duct to it is as deep as the height of the radiator,as wide as the radiator,and airtight construction.
I added a little more nose to my truck to get the depth of the duct equal to its radiator height.I'm cheating on width,but so far no problems.

[Kestrel]

That is vastly more confusing than I thought it would be! I'm honestly not sure what to make of those pics and formulas.

[aerohead]

Originally Posted by Kestrel

That is vastly more confusing than I thought it would be! I'm honestly not sure what to make of those pics and formulas.

The place here where I use the computer closes in 5-minutes.I'm sure other members will jump in.
*Measure the height of your radiator.
*Measure the distance from your grille,back to the face of the radiator.
*If the distance to the radiator isn't equal to the radiator,you might have to consider extending the nose.
*Check out my later images,there should be 4 of them now.
gotta go.

[jedi_sol]

Since you are barely starting out, you can start by covering the back of the honey comb.

OEM grilles are designed with worst case scenario (towing a trailer, in death valley, up a hill, with ac running). Therefore, typical daily driving, you can get away by covering a lot more of your grill openings.

Each car is different, everybody here learns with trial and error. You can start by blocking off as much as you feel comfortable (maybe start at 80% coverage or so)

If you start to notice your cooling fan comes on a lot more often, then trim your grill block down.

For the front air damn, general rule of thumb is that the air damn should only extend down as low as the lowest part of your under car. If you go lower, you are increasing frontal area, which is bad for fuel economy. Again each car is different, therefore you can play around with different sizes.

Cardboard is a cheap material to test the viability of mods. Then when you are set to make a permanent one, you can use any number of materials (fiber glass, abs plastic, coroplast, lawn edging)