Quote:
Originally Posted by chillsworld
Good things never go out of style sir... I'd kill to have a mercury with a punched hood... And serious aero/FE mods 
But in all seriousness... Would louvers be an appropriate way to test hood venting? Or perhaps even an exterrior form of a ducted radiator? Instead of having a huge gaping hole in your hood, could the duct lead up to a section of well done louvers that wouldn't restrict exit air flow but assist in directing the air where you want it to go?
~C |
Without a wind tunnel,you could tuft your hood,get it up to say 25-mph and photograph it.
Where the tufts were crowding together (I'm thinking near the A-pillars),this would be the lowest pressure area on the hood (Bernouli's Theorem).
This would be the place for the louvers.
If you had a junkyard hood,you could experiment,moving the louvers around,while simultaneously re-skinning the last area investigated.
If the engine bay were airtight,each 'hole' would carry half the volume.
The trick is to get the air out at the same velocity as the air it's flowing into,and directed parallel to that flow.
This is where the louvers slits might not be ideal.
Here is a 'poor' shot of the CNR,you can see how the extractors are aligned with the air/oil trace on the body.The size and orientation of the nozzles required at least $100,000 in tunnel time to dial in.They are perhaps the most scientific extractors on Earth.
http://www.cardesignnews.com/servlet...ICE_CONF_ID=68