I was wondering if anyone has any thoughts on improving airflow around the engine (front mounted)? I was thinking of making a radiator shroud between the engine and radiator. The shroud would begin at the bottom of the radiator as far forward as possible. The top of the shroud would be as far back as possible creating as much angle as possible. This shroud would contain all of the airflow leaving the radiator. All others sources of airflow could then hopefully be blocked from entering the engine compartment. The shroud would direct the airflow into a wide duct, which could be as simple as light flashing attached across the entire underside of the hood. The duct could then vent across the entire width of the hood between it and the windshield. If the underside of the compartment was belly panned and the compartment itself was sealed off the only air coming in would have to move through the shroud and duct.
It seems that unless you suffer a really big weight penalty it could help the economy of the vehicle by directing the airflow and missing a lot of flat vertical surfaces on the engine and in the engine compartment.
My other thought is that the engine and under hood components must receive some benefit in cooling from the air flowing around them normally. So their could be unforeseen problems in doing this.
Or could the whole thing be a waste of time because after the air passes the radiator it becomes "dead" and you would not suffer anymore aerodynamic penalty afterwards?
What are you working on? Rads are mounted to the front mostly because it's easier, but it isn't necessarily required. It can be mounted anywhere you can get airflow to it at. Provided you could draw air in, and protect it from road debris, you could even mount it at the rear of your vehicle.
I made a engine belly pan for my Civic. I was apparent that mass amounts of air were coming up from under the car. Ive owned many FWD cars in the past and NONE had this much trash carrying underhood air movement. Not even our current Accord has as much.
The pan helped a whole lot. The engine bay now stays very clean. Even cleaner than the Accords. The car doesn't have grill blocks as of yet. But the engine belly pan really helped. Its like night and day.
I was hoping that it would help with air drag. But I cant tell its done a darn thing for the mpg. The engine bay stays way cleaner. and I like my engines clean.
09 HCHII, w/Navi
07 Mazda3 S Touring, 5MT
Mild Hypermiler or Mad Man?
boofighter- I was thinking of running the entire length of the hood and having the air exit where the hood meets the windshield. However yours is a much better idea. Also thinking about what Telco said above I could move the rad or just adjust its mounting angle tilting it back in conjuction with duct work and vent through the hood. Then seal the air off from the rest of the engine compartment. Same effect less work less weight.