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Old 09-10-2012, 11:58 AM   #17 (permalink)
Aero Deshi
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Join Date: Jan 2010
Location: Vero Beach, FL
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MagMetalCivic - '04 Honda Civic Sedan EX
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Isn't the lowest possible CdA what we're after here. Seems to me like if adding 4 square feet to a 78 square foot truck with a Cd of .43 and getting the Cd down to .37 we'd go from 33.54 CdA to 30.34 CdA, looks like a 10% improvement to me.

I think it's a matter of how much of an improvement can the frontal area adding modification make. In this case, it seems if the top foil is executed well and the front transition area can be improved as well as getting close to template in back, I'd think there would be about this type of improvement of 10%. I'm not being unreasonable on my numbers here am I? I don’t think the Ford Ranger with a “traditional” square cap is doing much better than .43 and a .37 Cd isn’t an unreasonable spit wad number based on the other projects we’ve seen done and get all excited about. Adding 5% area to get a 10% gain, and with the tail cone, the Cd should drop to .32 or better leading to a 22% overall improvement.
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