Scion tC Grill block, feedback & suggestions

[rvpps2rocks]

Hey guys like most people was looking to get better MPG.

First of all i average 27 mpg and i did the grill block to both grills, I started with the bottom and got 27.5 -28 and had no overheating issues.

I had time this weekend to do the top one and drove around; Here in so cal this week the temperature outside was about 105 so i had the AC on when i noticed my car temp sky rocket.

I need to modify this full grill block to be a partial but dont know which grill to modify. and how much?

Heres both(well bottom out)

and some close ups

[rvpps2rocks]

Also does having the grill block behind the grill decrease my results?

[aerohead]

If you'll do a search for 'photo albums',then click on Phil Knox's aerodynamic photo albums,then click on the 'books' album,you'll find Walter Korff's schematic for a safe, low-drag grille-block.
This would be your safe 'minimum',and it will keep your cooking safely in the kitchen and not under your hood.

[rvpps2rocks]

What i wasnt sure on was what do you do if the length does not equal the height of the radiator, Im assuming your referring to the image below

[Prophecy99]

i have been seeing this foam for grille blocking and aero stuff. what is it exactly?

it looks like the same foam from insulating pipe sleeves just flat.

[rvpps2rocks]

the foam i think your thinking of comes in a can, and yes its for insulating pipe sleeves or filling holes.

I used a sheet of abs plastic i had

[aerohead]

Originally Posted by rvpps2rocks

What i wasnt sure on was what do you do if the length does not equal the height of the radiator, Im assuming your referring to the image below

yes,this is the animal.And it does need the length and gentle wall divergence for no flow separation inside.
Your car already has good leading edge radii,so bumping out the nose to accommodate the duct length might not in itself lower drag (it might in crosswind),but if you did it,you'd have a worry-free monster grille block.