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Old 07-27-2019, 10:01 PM   #11 (permalink)
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Quote:
Originally Posted by Snax View Post
I used 1/2" underground sprinkler hose set into a groove behind the spokes to screw the coroplast into directly. It can be a challenge to line up all of the screws, but seems really solid so far.
Love the idea, just keep in mind the coro discs will murder the finish on your OEM wheels.

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Old 07-28-2019, 09:00 AM   #12 (permalink)
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I wanted taller than stock rims that were also lighter, so I ended up with 15" 2007 BMW MINI seven hole rims (12 lbs). For a cover I blanked the holes from behind to create a "flat" surface preventing airflow THROUGH the rim face. This should prevent almost as much wheel drag as smooth covers while keeping my overall weight to about 12.5 lbs per wheel. Smooth covers would do slightly better but they tend to go onto heavier wheels, to which the cover itself adds weight.

Here is some of the data behind the thought behind blanking lightweight rims:



Here is the look:




CITATIONS:

This is mostly a reposting of post #421 in my own modding thread (see link in sig file below).

"AEROHEAD" opinion cite... somewhere on ecomodder.com I swear it.

Alexey Vdovin, "Investigation of Aerodynamic Resistance of Rotating Wheels on Passenger Cars," (Gothenburg, Sweden: Department of Applied Mechanics, CHALMERS UNIVERSITY OF TECHNOLOGY, 2013).
http://publications.lib.chalmers.se/...302/176302.pdf

See also:
http://publications.lib.chalmers.se/...ext/133661.pdf
"Blocking the crossflow through the rims result in increased static pressure in the front wheel house and thereby an increase in lift, whereas blocking the crossflow in the rear result in increased downforce due to an increased flow rate through the diffuser. It was however shown that the resulting flow around the rear wheel was highly dependent of the rim design in the front."
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Old 07-28-2019, 11:21 AM   #13 (permalink)
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Quote:
Originally Posted by conor_v View Post
I've been inspired Snax. .
Awesome!
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Old 07-28-2019, 11:26 AM   #14 (permalink)
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Quote:
Originally Posted by oldtamiyaphile View Post
Love the idea, just keep in mind the coro discs will murder the finish on your OEM wheels.
A solid reminder!

Fortunately the way it attaches doesn't allow any shifting on the wheels when tightened without a significant mechanical bump, but more refined future iterations will have appropriate padding / standoff material to further limit or prevent that.
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Old 07-28-2019, 11:48 AM   #15 (permalink)
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These look really good. Has anyone seen any problems with overheating brakes because of these coverings? Will this cause faster brake pad wear?
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Old 07-28-2019, 12:30 PM   #16 (permalink)
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Quote:
Originally Posted by California98Civic View Post
I wanted taller than stock rims that were also lighter, so I ended up with 15" 2007 BMW MINI seven hole rims (12 lbs). For a cover I blanked the holes from behind to create a "flat" surface preventing airflow THROUGH the rim face. This should prevent almost as much wheel drag as smooth covers while keeping my overall weight to about 12.5 lbs per wheel. Smooth covers would do slightly better but they tend to go onto heavier wheels, to which the cover itself adds weight.

Here is some of the data behind the thought behind blanking lightweight rims:



Here is the look:




CITATIONS:

This is mostly a reposting of post #421 in my own modding thread (see link in sig file below).

"AEROHEAD" opinion cite... somewhere on ecomodder.com I swear it.

Alexey Vdovin, "Investigation of Aerodynamic Resistance of Rotating Wheels on Passenger Cars," (Gothenburg, Sweden: Department of Applied Mechanics, CHALMERS UNIVERSITY OF TECHNOLOGY, 2013).
http://publications.lib.chalmers.se/...302/176302.pdf

See also:
http://publications.lib.chalmers.se/...ext/133661.pdf
"Blocking the crossflow through the rims result in increased static pressure in the front wheel house and thereby an increase in lift, whereas blocking the crossflow in the rear result in increased downforce due to an increased flow rate through the diffuser. It was however shown that the resulting flow around the rear wheel was highly dependent of the rim design in the front."
Your wheels look awesome! Also, thanks for the studies. They were VERY interesting to read.
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Old 07-28-2019, 02:00 PM   #17 (permalink)
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Quote:
Originally Posted by Taylor95 View Post
These look really good. Has anyone seen any problems with overheating brakes because of these coverings? Will this cause faster brake pad wear?
I think overheating concerns within this group largely only center around heavier vehicles on long descents. Most of us so significantly limit our use of the brakes that overheating just doesn't happen. On my i3, I don't even use the brakes for all but a couple seconds at a time if I even use them at all. And heat generally does not reduce pad life, just effectiveness. (Exceptions always exist however.)
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Old 07-28-2019, 05:19 PM   #18 (permalink)
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Some great ideas guys! I just converted the Mirage back to steel wheels instead of my alloys. Its SO much easier to put smooth covers on steel wheels. I'm going to have to think about this.
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Old 07-31-2019, 02:34 PM   #19 (permalink)
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Quote:
Originally Posted by oldtamiyaphile View Post
Love the idea, just keep in mind the coro discs will murder the finish on your OEM wheels.
Finding this to be true far sooner than expected!

Fortunately I should still be able to polish out what is there, but will be padding them in the next iteration which is an ABS like material that is thinner and cleaner looking.
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Old 07-31-2019, 10:25 PM   #20 (permalink)
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Has anyone tried these, pizza pans with "nibs", which would mean small concave depressions on the outer wheel face (ala golf ball)?

https://www.webstaurantstore.com/sea...-pan-nibs.html

Surely there's some validity to localized energy being added to the flow helping it attach?

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