07-27-2019, 11:01 PM
|
#11 (permalink)
|
Master EcoModder
Join Date: May 2009
Location: Australia
Posts: 1,510
Thanks: 325
Thanked 452 Times in 319 Posts
|
Quote:
Originally Posted by Snax
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.
|
|
|
The Following User Says Thank You to oldtamiyaphile For This Useful Post:
|
|
Today
|
|
|
Other popular topics in this forum...
|
|
|
07-28-2019, 10:00 AM
|
#12 (permalink)
|
Cyborg ECU
Join Date: Mar 2011
Location: Coastal Southern California
Posts: 6,299
Thanks: 2,373
Thanked 2,174 Times in 1,470 Posts
|
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."
__________________
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.
|
|
|
The Following 4 Users Say Thank You to California98Civic For This Useful Post:
|
|
07-28-2019, 12:21 PM
|
#13 (permalink)
|
Master EcoModder
Join Date: Dec 2008
Location: Eugene, OR, USA
Posts: 382
Thanks: 90
Thanked 170 Times in 126 Posts
|
Quote:
Originally Posted by conor_v
I've been inspired Snax. .
|
Awesome!
__________________
2015 BMW i3 REx
2011 Ford Flex SEL AWD
|
|
|
07-28-2019, 12:26 PM
|
#14 (permalink)
|
Master EcoModder
Join Date: Dec 2008
Location: Eugene, OR, USA
Posts: 382
Thanks: 90
Thanked 170 Times in 126 Posts
|
Quote:
Originally Posted by oldtamiyaphile
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.
__________________
2015 BMW i3 REx
2011 Ford Flex SEL AWD
|
|
|
07-28-2019, 12:48 PM
|
#15 (permalink)
|
Master EcoModder
Join Date: Aug 2018
Location: USA
Posts: 455
Thanks: 180
Thanked 101 Times in 77 Posts
|
These look really good. Has anyone seen any problems with overheating brakes because of these coverings? Will this cause faster brake pad wear?
|
|
|
07-28-2019, 01:30 PM
|
#16 (permalink)
|
EcoModding Lurker
Join Date: Jul 2019
Location: Pennsylvania
Posts: 23
Jerry - '11 Chevrolet Volt
Thanks: 3
Thanked 8 Times in 3 Posts
|
Quote:
Originally Posted by California98Civic
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.
|
|
|
07-28-2019, 03:00 PM
|
#17 (permalink)
|
Master EcoModder
Join Date: Dec 2008
Location: Eugene, OR, USA
Posts: 382
Thanks: 90
Thanked 170 Times in 126 Posts
|
Quote:
Originally Posted by Taylor95
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.)
__________________
2015 BMW i3 REx
2011 Ford Flex SEL AWD
|
|
|
The Following User Says Thank You to Snax For This Useful Post:
|
|
07-28-2019, 06:19 PM
|
#18 (permalink)
|
Administrator
Join Date: Dec 2007
Location: Germantown, WI
Posts: 11,203
Thanks: 2,501
Thanked 2,588 Times in 1,555 Posts
|
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.
|
|
|
07-31-2019, 03:34 PM
|
#19 (permalink)
|
Master EcoModder
Join Date: Dec 2008
Location: Eugene, OR, USA
Posts: 382
Thanks: 90
Thanked 170 Times in 126 Posts
|
Quote:
Originally Posted by oldtamiyaphile
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.
__________________
2015 BMW i3 REx
2011 Ford Flex SEL AWD
|
|
|
07-31-2019, 11:25 PM
|
#20 (permalink)
|
EcoModding Apprentice
Join Date: Apr 2012
Location: Charlotte, NC
Posts: 134
Thanks: 146
Thanked 110 Times in 47 Posts
|
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?
|
|
|
|