I definitely have to agree with these guys on air obstruction.
Have you ever seen "your mock-up lighting configuration" done before on a street/off road car, or rally Forester?
If so, any possibility finding out if they had any air flow problems (A/C performance or overheating at highway speeds).....or if they did other mods. to resolve the air-flow restriction like hood extractors or higher output electric fans??????
I've spent a while doing Google Image Searches on "Forester Offroad Ralley Lightbars" and will post many of the links in another post
if they allow me to. I did just find the closest configuration that you want to do on a Forester from Sweden and they also warn him about engine temps when the weather warms up......maybe try contacting him:
http://www.subaruforester.org/vbulle...lights-106948/
Here's my take on it as I know a lot about air flow dynamics in the HVAC industry and mainly related to hi-rise building construction of how air flows around a structure which causes high and low pressures on the exterior and interior of the structure, but my passion has always been in hi-perf. car mods and tuning so in this instance, this theory would apply.
Here's the technical explanation of what I believe could occur and be a problem:
At idle or light cruise you won't have any problems with overheating or air flow past the A/C Condenser since the ECM will ramp-up the fans (if that's how Suburu works) to control your electric fans. But at 10mph/16kph ++++ things will change quickly as you will start to loose all ram air flow into the front of the upper grill opening where the electric fans can't compensate for the loss of ram air velocity since the OEM aerodynamics has been changed by the obstruction of the very large mass of the new light housings....
I believe with that large mass of lights on the front bumper it will definitely cause problems but could be verified with a manometer like my Dwyer Digital Manometer #475 or any cheap "analogue differential manometer" would work where you would run long 1/4" tubing to measure high/low pressures or + or - differences while driving.......racers do this when modding the front of a race car for aerodynamics.
This is what I think will occur that you should be aware of and consider if no one out there has done the same config. successfully that you want to do and didn't have problems:
1. that large mass will cause a High Pressure bubble in front of all those lights and air will travel around them in the least restrictive path which would be over the top of the housings. At slower speeds it will be a turbulent flow then linear flow as speed increases. Have you ever seen video of how they demonstrate a cars aerodynamics in a wind tunnel with a smoke wand.....pretty cool.
2. You will probably then develop a low pressure center behind the lights which will most like start to cause a "venturi effect" extracting/suck air out from behind the grill.
3. Since the only unobstructed air you will have is going through the lower unobstructed grill; the high pressure air will be more than it used to be in that area because there is now a low pressure behind the upper grill and you will literally start to get high velocity of air going through the lower opening, and coming out the upper grill and over the hood. The faster you go, the more velocity you'll have and the higher the pressure, until you will eventually start pulling/sucking air under this vacuum through the front radiator and a/c condenser which will be a reversion of air flow....I'm pretty sure it could happen.
4. You would need to somehow overcome this reversion by installing hood extractor vents to allow the ram air from the lower grill intake along with the cooling fans to move air back through this area and hopefully the hood vents if placed properly in a low pressure section of the hood, will extract air out restoring air flow through the rad. and a/c condenser. Although, even at high way speeds, there maybe so much velocity through the lower grill and out the upper grill, the hood vent could exasperate the problem and create more of a reversion with negative pressure and suck air instead of extracting and venting the air from the under the hood where high pressure should build.
But you are in the right place asking about lighting from the lighting experts like Scheinwerfermann, Alaric Darconville and others as I'm also needing their help on a lighting project for my Cadillac's.
I'll post all the links in another post of different light bars on Foresters. Many of the links are from the massive forum called "Subaru Forester Org." where they have 34.pgs on the "Official Aux Lighting Thread".
But who knows if they know what they're talking about with lights and I'd stick with these guys here for their expert knowledge and that forum for at least ideas and pictures!
Regards,
Chris