Where to take in air ?

[roverman]

Reportedly up to 2/3 of the total air drag of a passenger car is from front of vehicle to "base" of winshield. I suspect taking in massive amounts of air in a front grille helps contribute to this overall drag considerably. Case in point, the 914 Porsche has a CD of .39 ? This not because it has beautifull, flowing, smart aero lines, but partly perhaps of no front air inlet. Because of this, I shall test a closed off front, on the Hemi Healey. The TR6 like, flat area on the rear, creates a suitable low pressure area to dump  cooling air from rear wheel wells and radiator. To be continued, roverman.

[socorob]

http://www.autospeed.com/A_2159/cms/article.html

Do some reading around on this site, lots of good aero info there

[MGBV8]

Art,

I see it as more to do with the frontal square footage.  Where did you get that low CD number?

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914 CD's

1)top on,windows up,&headlights shut CD .363
2)Headlights up CD.380
3)headlights up, windows open CD .381
4)same as above but roof off CD.484

[Preform Resources]

Years ago  a couple rally guys put a Volvo six from a boat in some small car and put the rad in the deck as you are suggesting Art, they took air in on the rear qtrs thru Naca ducts and it worked, Naca ducts don't create drag, however for them to work
they need to be located where attached air is available. Here is a Carbir sports 2 car that we developed  a naca duct intake
30 sq. in. opening, ducted back to the rad (in front of the rear wheel) and built a dedicated duct for the air to flow to the rad.
then dumps out the back of the body .
Dave Craddock

[roverman]

Carl, my brain did a "typo". OK, I bought a "Magenehelic" pressure differential gage,ebay,+/- 1 hg. This should prove easier use for 1 person, than yarn and a camera, etc. Naca ducts "look cool" and don't ad additional drag, BUT become less effective with speed as their laminar flow, boundary layer increases with speed. Now "if" they had a crafty shape on the floor, like Wheeler Vortex Generators or such, who knows ?  I'm thinking if I couldmake  something under the car, similar to Ferrari F355, then WOW ! To be continued, roverman.