08-19-2018, 07:42 PM
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#741 (permalink)
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Cyborg ECU
Join Date: Mar 2011
Location: Coastal Southern California
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Quote:
Originally Posted by gumby79
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I want to tell you that I looked at your album on your EM page too, and this is a cool looking wing from profile, too. It has a zoomorphic look--like bat or cat ears. Thanks for fixing the video link. The tufts look great. What is the reason for the "ears"? Redirecting flow toward the boat tail?
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See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.
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Other popular topics in this forum...
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08-19-2018, 09:24 PM
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#742 (permalink)
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Master EcoModder
Join Date: Dec 2014
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Quote:
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What is the reason for the "ears"? Redirecting flow toward the boat tail?
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It is part of the functional design of the standalone headache rack/ long load carrying support to prevent damage to cab from ladders and long pipe.
I made a mistake matching the silhouette of the back of a cab, wound up being too short on the corners and dead even in the center(load sitting on cab sheet metal). So I added the flat 1:24 wing (24x longer than thick =1/8"×3)with 3/16" positive camber(nose up) center 0° off horizontal, 3/8" pos. camber at the tips. The triangular supports mid-span are also set to approximately 10 to 15 degrees out of air flow travel direction ( would cause counter-rotating vortexes off of each leg of the triangle
All wings that produce lift have down wash. So yes the patch(wing) is designed to use the down wash to catch and mitigate the turbulence caused by the cab to canopy gap ( second thing the wing patch was the cab angles forward resulting in my ideal half inch at the base of a headache rack and 3.5" at the top).
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Quote:
freebeard
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It demonstrates what is happening in the wheel wells very nicely. At 0:03 and 0:51
Sorta. It would be better with the wheel rotating.
Yesterday 07:43 AM
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agreed spin would be better . Best would be engine running at various speeds primarily Peak torque and Peak horsepower and a moving floor treadmill, while we're at it dreaming big put that treadmill on a turntable so we can account for crosswind interaction. wind is almost never straight on so the strate up wind tunnel testing only demonstrates about 2% of real world conditions primarily the Gorge between Bonneville Dam and The Dalles
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1st gen cummins 91.5 dodge d250 ,HX35W/12/6 QSV
ehxsost manafulld wrap, Aero Tonto
best tank: distance 649gps mi 24.04 mpg 27.011usg
Best mpg : 31.32mpg 100mi 3.193 USG 5/2/20
Former
'83 GMC S-15 Jimmy 2door 2wd O/D auto 3.73R&P
'79 Chevy K20 4X4 350ci 400hp msd custom th400 /np205. 7.5-new 14mpg modded befor modding was a thing
87' Hyundai Excel
83 ranger w/87 2.9 L FI2wd auto 18mpg on the floor
04 Mitsubishi Gallant 2.4L auto 26mpg
06 Subaru Forrester XT(WRX PACKAGE) MT AWD Turbocharged 18 plying dirty best of 26mpg@70mph
95Chevy Blazer 4x4 auto 14-18mpg
04 Chevy Blazer 4x4 auto 16-22mpg
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08-22-2018, 05:00 PM
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#743 (permalink)
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Master EcoModder
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Quote:
Originally Posted by ratgreen
Some interesting results. The front dam actually made its Cd worse
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I won't post the newest Leroy video because it isn't a "smoke" related picture or video.
However, they did "smoke" a record...
7.824 seconds in the 1/4 mile at 176.57 mph. 
All horsepower no aero.
Imagine what it could do with a properly designed body.
If you want to see the video just Google it.
WORLD'S FIRST Stick Shift GM In The SEVENS! Leroy's Most INSANE Pass!
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10-08-2018, 02:57 AM
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#744 (permalink)
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Master EcoModder
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Just A Car Guy: streamliner... origin of the word
I thought this might be appropriate for this thread, but when you get to the bottom there is a Youtube video from this channel:
https://www.youtube.com/channel/EcoModderDOTcom
With 491 subscribers, one video posted a year until two years ago. Who's in charge?
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.Without freedom of speech we wouldn't know who all the idiots are. -- anonymous poster
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.Three conspiracy theorists walk into a bar --You can't say that is a coincidence.
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10-09-2018, 09:02 PM
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#745 (permalink)
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Master EcoModder
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Random but not smokey. I'm not sure where to put what I found:
Aerodynamic Car Shapes^@#
I don't recall seeing those before.
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.Without freedom of speech we wouldn't know who all the idiots are. -- anonymous poster
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.Three conspiracy theorists walk into a bar --You can't say that is a coincidence.
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10-10-2018, 10:38 AM
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#746 (permalink)
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Master EcoModder
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Top image using a reverse image search says:
https://www.evolutionm.net/forums/mo...iffuser-4.html
Link is from 2009 and broken, but we now know the source.
NOTE: Image also found here with some other Aero-Images.
http://linkpat.info/aerodynamic-shapes-b593.html
Race Car Aerodynamics: Designing for Speed (Technical including tuning & modifying) by Joseph Katz (2006) Paperback
https://www.amazon.com/Race-Car-Aero.../dp/B00NPNUQX0
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George
Architect, Artist and Designer of Objects
2012 Infiniti G37X Coupe
1977 Porsche 911s Targa
1998 Chevy S-10 Pick-Up truck
1989 Scat II HP Hovercraft
You cannot sell aerodynamics in a can............
Last edited by kach22i; 10-10-2018 at 10:45 AM..
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10-10-2018, 12:05 PM
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#747 (permalink)
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Master EcoModder
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Any luck with the second one? VW-P3 appears equivalent to my Dasher while VW-P4 appears equivalent to the Rabbit/Golf.
I don't understand the two VW-P4 but only one VW-P3 profiles.
It looks like if the Dasher's profile was pushed to 74° it would be a slippery as the Golf/Rabbit. Does it make sense to apply the lower left scenario to the upper profile?
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.Without freedom of speech we wouldn't know who all the idiots are. -- anonymous poster
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.Three conspiracy theorists walk into a bar --You can't say that is a coincidence.
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10-10-2018, 12:56 PM
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#748 (permalink)
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Aero Wannabe
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Quote:
Originally Posted by freebeard
Any luck with the second one? VW-P3 appears equivalent to my Dasher while VW-P4 appears equivalent to the Rabbit/Golf.
I don't understand the two VW-P4 but only one VW-P3 profiles.
It looks like if the Dasher's profile was pushed to 74° it would be a slippery as the Golf/Rabbit. Does it make sense to apply the lower left scenario to the upper profile?
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Perhaps these were all wind tunnel mock-ups of the mkI Golf/Rabbit. The 34 degree in the lower left looks closer to the mkIV Golf (my car) and if I read the graph correctly the triangles show lower Cd. Somewhere on here I remember seeing the back should be chopped at vertical for lowest drag.
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60 mpg hwy highest, 50+mpg lifetime
TDi=fast frugal fun
https://ecomodder.com/forum/showthre...tml#post621801
Quote:
Originally Posted by freebeard
The power needed to push an object through a fluid increases as the cube of the velocity. Mechanical friction increases as the square, so increasing speed requires progressively more power.
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10-10-2018, 03:13 PM
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#749 (permalink)
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Master EcoModder
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When I put a protractor on this I ascertain ~25° from horizontal, AKA 65°. The diagram seems to me to be ambiguous about whether the angle is measured from the top or bottom and from the horizontal or vertical.
I think what I need for a Kammback is a short top with tapering sail panels.
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.Without freedom of speech we wouldn't know who all the idiots are. -- anonymous poster
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.Three conspiracy theorists walk into a bar --You can't say that is a coincidence.
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10-10-2018, 03:17 PM
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#750 (permalink)
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Master EcoModder
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Quote:
Originally Posted by freebeard
Any luck with the second one? VW-P3 appears equivalent to my Dasher while VW-P4 appears equivalent to the Rabbit/Golf.
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I looked for about seven minutes and did not find it's true source.
However I found this nifty PDF from India (a download).
https://www.google.com/url?sa=i&rct=...39281492253127
And a review of the preciously mentioned book including a few pages of the inside.
2013
Racecar Aerodynamics: Designing for Speed by Joseph Katz Book Review
The Avid Engineer: Racecar Aerodynamics: Designing for Speed by Joseph Katz Book Review
Quote:
Conclusion:
I really rate this book highly and I often find myself referring to it over some of my more analytical books like Understanding Aerodynamics by Doug McLean. The way the author always explains concepts in such a clear and concise manner is especially welcome, which is helpful if like myself you are a keen F1 fan and often find the televised explanations lacking and need a quick reference just to suss out possible benefits of recent changes. In this regard the book would make an excellent present for any one interested in forms of racing.
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EDIT: I just liked this picture...................
http://forums.pelicanparts.com/off-t...taken-631.html
I wonder what the little guy's Cd was.
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George
Architect, Artist and Designer of Objects
2012 Infiniti G37X Coupe
1977 Porsche 911s Targa
1998 Chevy S-10 Pick-Up truck
1989 Scat II HP Hovercraft
You cannot sell aerodynamics in a can............
Last edited by kach22i; 10-14-2018 at 12:58 PM..
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