VX Grill block ?
 

I've been thinking about making a grill block, & took a good look at my grill tonight. Looking at this picture, what more do I need? Am I trying to make the space flush with the front of the car, or is this OK?

I would personally try to make it flush with the bumper, but I think that may work alittle too. Making it flush is gonna create less turbulence than with the ribs exposed..

Why would there be turbulence? From what I have read, there ends up being a cushion of air in that place... reasonably static. But I could be wrong.

I am thinking though, that unless you place a parabolic shape in front, for which all air would streamline around, not matter what the shape of the concavity is, you end up pretty much the same.

I have the same stock grill block as you, I then added a flush grill block (check my garage) that is simply caulked in to place, I did it mostly to make the opening even smaller, so now it only leaves the last set of slats open, and in 105 degree weather I didn't have any problem over heating.
I beleave you are correct in the buffer of air idea, most of the air drage on a vehicle is at the rear end where it is coming back together as it flows around the vehicle, but what the grill block really helps with is reducing the amount of air going in to the engine compartment, as that air has to exit at some point, and it can't flow in a straight line, as the engine is in the way.

On my '95 Civic DX, I didn't make it flush. I used some old real estate coroplast signs, cut them into three pieces (because one sign or two signs weren't big enough to make one or two big pieces), and used tie wraps to secure them to the grill. I also blocked the small grills on both sides of the large center grill.

Ryland, did you notice any FE improvement of this grill block at all? I am sure that it is theoratically better for aerodynamics, just wondered what the FE improvement in real life is.

Hmm, I would think that opening would cuase it to be less streamlined than if it was flush. Never heard of that air pocket thing..

On my metro the headlights are recessed with a big cavity. I would think that causes some bad aerodynamics since its practically 2 scoops on the car...

Wonder if you could just get some Suzuki Swift headlights to fill that gap up. The Swit, at least in Europe, never had those recessed lights. Here is a pic of a 1993 Suzuki Swift for sale in the Netherlands:

https://fotos1.marktplaats.nl/kopen/2...28e4404dec.jpg

Probably be easier to fit mk5 lights into my mk4 since they are flush..

Im not to that point yet though :P

my mileage goes up and down so much that it's hard to get a good reading to tell what works, and what doesn't, sorry.
I need to update my gas log, but I try to keep notes of things like doing the grill block.