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Old 08-23-2008, 03:19 PM   #23 (permalink)
aerohead
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counts

Quote:
Originally Posted by Tango Charlie View Post
What are 'counts of aero' ? Is this a GM buzz word, or is it an aerodynamics's term?
Doax is correct.I have only two sources which use the term.One a 1982 article by Road & Track,the other Mechanical Engineering Magazine.

---------------------------- The term is considered valid when associated with a particular development vehicle ( like the Volt ),in a particular wind tunnel ( like GM's).

------------------------------- Also,Road and Track "rounds" counts within Cds published by carmakers.

-------------------------- Example: A Firebird,which scored Cd 0.316 would be rounded up to 0.32. A GMC S-15,with Cd 0.495 would remain 0.495,and a car with Cd 0.294 would receive 0.29.

-------------------------------- So like the discussion about the CRX HF,and CRX Si,they may have only been separated by a few "points",however when "rounded",look more dramatic in efficiency differences.

------------------------------ I suspect other magazines also "round." Very frustrating when attempting to distinguish individual features,adding or detracting from aero efficiency.

--------------------------------------- To cloud matters even further,the EPA does not recognize"protuberances" when factoring sectional area.If a vehicle is tested with antenna and sideview mirrors,their area is not factored into drag measured,leading to an arbitrarily high Cd.

-------------------------- Drat!!!!!!!!!!! A can of worms!
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