grillblock in front, not against grill ?
 

has anyone ever tried an external grillblock that sits in front of the grill rather than against it?
the idea is that i'd install a lip (a found a very nice piece of plastic that's just right) in front of the open area of my lower 'grill', basically turning the intake from faceing forward to faceing downwards

the red area is the dam i plan to install
http://i77.photobucket.com/albums/j5...ighway/RAD.png

the basic thought behind this is that it might cancel out the ram effect somewhat reducing the air intake at speed, but allow a maximum volume of air to enter naturally or be sucked in by the fan when the car is moving slowly and most at risk of overheating.

i plan to try this but does it look like it might work or should i look for a different approach?

Why not just block the entire thing?

cause i'm pretty sure that'll get me into trouble. i can get away with a full top block on my normal commute, but during the summer i once got stuck for maybe 10-15 minutes in very slow moving traffic, and temps went way beyond where they should be... needle was all the way up into the red by the time i pulled ont the driveway.

i maybe get traffic like that once in 2 months for maybe 10 to 15 minutes, but it's usually not the sort of traffic that allows you to pull over to remove a grillblock, so whatever setup i have needs to cope with these situations.


both grills are quite small and the topgrill as more than 50% blocked from the factory so i think the engineers did their math.
on the other hand i do feel like the existing area while small is only really needed when the cars moving slowly, so i thought it would be great it i could make some sort of shield that would push the air aside as the car punches trough the air, but leaves enough room around the sides and so that the same volume of air can easily be sucked in by the fan.

the question is will this happen or will the same volume of air still enter the radiator regardless of what's in front of it.

i'd like an all season setup that's an improvement over stock even if this isn't ideal compared to a full block, but doesn't needs me to look at the temp gauge all the time

Personally, I think the best solution is a variable/adjustable grille block. Like this one: http://ecomodder.com/forum/showthrea...abin-6358.html

i'm also working on a variable grillblock, but it's easier said than done on some cars.
i've looked at existing vents but found non suitable for my car's layout, and while working on a fully scratchbuild active grillblock has been fun so far, it'll be quite some time before i entrust it with the safety of my engine....

aerodynamicly speaking they're superior but they'd still require either you or a mechanical or electric device to monitor the temperatures,, all these can potentially fail and add complexity.

a device that uses the laws of physics to create a virtual full grillblock at speed, but offers no restriction when the car is moving slowly; and that without the use of moveing parts sounds quite appealing to me... IF something like what i describe can actually do that, wich is the reason for this post really.

anyway, yesterday i slaped the piece of plastic on my car, and although i only drove for a short distance i noticed that the engine temp was a little higher, but still not above my summer average (this was with the heater running though and i know that makes a big difference)

the car felt different, although not really in a nice way. i think the what the front bumper is designed with works a bit like a splitter, and perhaps the fairing removes some downforce there.
also the stagnation point might be a little lower now causing more air to go over the car, but as the lower grill is closed more air will go under as well.

to bad i don't have a ny good fe feedback of i would know immediately if it did something good or not

Can you provide us with some pictures of your front end to better understand you circumstance?

grillblock
 

I would at least roll some radius into the lower edge of the sheet,otherwise you've got a Cd1.11 obstruction in front of your opening,almost as much drag as a parachute.

Do a complete grille block, remove sources of external heat from the radiator. I.E. Secondary header shroud... Use a stronger fan, or a pusher fan, or add another fan to the open area of your radiator that isn't currently occupied by a fan (if you removed A/C fan) or wire the A/C fan so that it comes on with the coolant fan. This will help to draw more than enough air from places other than the grille to keep the car cool.

If you don't believe it, or need help realizing if it will work for you, do it, then drive out to a backroad on a hot day and let the car sit idling in the sun after driving it kinda hard. If the fans come on and never turn off, you need to channel more air into that area, which can be done with ducting rather than affecting the aero of the car.