Thanks MJFDDS, that's what I'm thinking. Someone else implied that the center plug directs air into the side radiators, but I don't see how it does.
Dave.

 

I don't see how it would either. I would think you would get the same amount of air if not more to the side radiators. To me it seems like it's just a cosmetic piece Porsche uses for the cars w/out center radiators.

 

As I recall from recently fabbing and installing a set of mesh grilles for a friend's GT3... there is no true ductwork to top vent from center radiator in a 997 GT3. Likewise center does not feed to outboard either. The center rad has a plastic "ear" around it (like the outboard condensers and rads do) that interlocks w/ black trim opening on bumper skin. Aside from aesthetics, these help direct air flow into and thru cooling surface.

That said, there are a few differences... if not using the black center filler panel and even if installing mesh screens you will need the GT3 center trim lip kit (to finish of the bumper skin locking tabs and provide a place to mount mesh to). As well, the center innards on a GT3 are black (bumper, bumper supports, etc.) so they cannot be seen from topside thru the "smile". Mesh will help hide most of it (yes - put behind smile too for consistency) but just do it right the first time and paint anything visible black - including behind center opening b/c in a GT3 the ear and rad would normally be there.

Good luck

 

Great feedback, thanks. Actually been thinking about painting the interior black, so thanks for that.
I believe the bumper came with the center kit you're describing as the previous owner had a third radiator. So I think I'm all set there. I have ordered the rennline GT3 mesh, for the top vent also.
I'm excited to get it painted and installed.
Dave.