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Reverse NACA ducts

 
Old 06-10-2019, 01:58 PM
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Default Reverse NACA ducts

Hey, looking to do some hood venting. I found these NACA ducts on ebay https://www.ebay.com/itm/NACA-air-ve...8AAOSw-0xYPZJd they are aluminum and come off a Grumman Tiger airplane for under $30 each. Thoughts on using these backwards for hood vents? Here is some info on running them backwards:
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Old 06-10-2019, 02:20 PM
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I remember seeing wind tunnel test results a few years ago for naca ducts mounted backwards. The conclusion was that the naca shape has no real benefit when mounted backwards, and a simpler vent shape is equally or more efficient. The naca shape really shines as an inlet.

It sounds like the nascar teams just did it because of a rules loophole. Wording like "no vents or holes may be placed in windows other than NACA ducts" with no specification for duct orientation. Their only options were backwards naca duct extractor or no extractor, and the backwards naca duct was the winner.
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Old 06-10-2019, 03:29 PM
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i also found that they are not great when run backwards
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Old 06-11-2019, 06:29 PM
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^ What they said.
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Old 06-12-2019, 01:32 PM
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Sounds good, thanks for the input! Gonna go with the 5 piece set of R Theory vents.
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Old 06-12-2019, 01:34 PM
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Originally Posted by 1RMDave View Post
Sounds good, thanks for the input! Gonna go with the 5 piece set of R Theory vents.
do the singular vents
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Old 06-12-2019, 01:40 PM
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Originally Posted by matrussell122 View Post
do the singular vents
I do like the Singular vents with the gurney flaps however this is one of those rare instances that I get to support the Canadian economy and probably save a lot on shipping. I may add my own gurney flaps to the R Theorys.
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Old 06-12-2019, 01:46 PM
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I thought R Theory's business was on hold?
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Old 06-12-2019, 03:47 PM
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Originally Posted by acedeuce802 View Post
I thought R Theory's business was on hold?
Oh I dunno... Still taking orders on website...
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Old 06-12-2019, 05:32 PM
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I sure hope I can get R theorys. Singulars will be $260usd
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Old 06-14-2019, 05:15 AM
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Originally Posted by 1RMDave View Post
I sure hope I can get R theorys. Singulars will be $260usd
Have the 5 piece R Theory on route out west, no issue with getting them ordered. Those singulars are just brutal after conversion and shipping :(
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Old 06-14-2019, 07:05 AM
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Originally Posted by dc2696 View Post
Have the 5 piece R Theory on route out west, no issue with getting them ordered. Those singulars are just brutal after conversion and shipping :(
Did you order them off the website?? How long ago did you order them? Thanks for chiming in, I'd still like to order the R Theory's! I can't believe some vendors want $65 usd to ship the Singular vents, that's almost $100cad and they ship flat so obviously no big box needed.
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Old 06-14-2019, 03:38 PM
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Originally Posted by 1RMDave View Post
Did you order them off the website?? How long ago did you order them? Thanks for chiming in, I'd still like to order the R Theory's! I can't believe some vendors want $65 usd to ship the Singular vents, that's almost $100cad and they ship flat so obviously no big box needed.
Yup ordered off the website on the 7th last week.
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Old 06-15-2019, 11:09 AM
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Originally Posted by dc2696 View Post
Yup ordered off the website on the 7th last week.
Did you get a tracking number or anything indicating they are on their way?
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Old 06-15-2019, 09:14 PM
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Originally Posted by 1RMDave View Post
Did you get a tracking number or anything indicating they are on their way?
Yup, should be here Tuesday
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