Go Back   EcoModder Forum > EcoModding > Aerodynamics
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 09-27-2008, 04:35 PM   #31 (permalink)
Mr. Blue Tape
 
azraelswrd's Avatar
 
Join Date: Jun 2008
Location: Fresno, CA
Posts: 345

AzxA - '06 Scion xA
90 day: 42.72 mpg (US)
Thanks: 0
Thanked 2 Times in 2 Posts
Time to retape my hubcaps then! Good find tas!

__________________


My 5 pillars of fuel efficiency:
  • driving style
  • aerodynamics
  • tires
  • weight reduction
  • engine maintenance
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 09-27-2008, 06:23 PM   #32 (permalink)
Master EcoModder
 
tasdrouille's Avatar
 
Join Date: Jan 2008
Location: Mirabel, QC
Posts: 1,672

The Guzzler - '08 Hyundai Elantra GL
90 day: 33.12 mpg (US)

Got Soul? - '11 Kia Soul 2U
Thanks: 35
Thanked 86 Times in 57 Posts
Quote:
Originally Posted by MetroMPG View Post
Those aftermarket rims are "air blenders"!

It's interesting to note that the exposed 19 inch rim is the worst case, but when masked, it's the 2nd best case - better than the masked 17 inch rim.

To me that suggests the shrinking gap between tire and wheel arch (you can see the progression in the photos) may be having a beneficial effect. And it may be even more significant if they didn't control for tire width as well (they apparently didn't control for overall circumference, so I'd be surprised if they did control for width).
You are right about the gap reduction. An interesting thing to note is that if all wheels were also blocked from the inside, the 17 inches and 19 inches wheels would do better than the steel rim. The reason for larger taped wheels to perform less than the 15 inches steel wheel with cover is that the disk brake cover most of the wheel opening from inside airflow in the smaller one, wheras there is a huge gap on the larger diameter wheels which increases ventilation resistance a lot. It would have be interesting to see them test something like a 205/75R15 with a steel cover. I'm pretty sure that would have been the best.

The tires tested were 195/65R15, 235/45R17 and 235/35R19.
__________________



www.HyperKilometreur.com - Quand chaque goutte compte...
  Reply With Quote
Old 09-27-2008, 06:42 PM   #33 (permalink)
Banned
 
Join Date: Feb 2008
Location: maine
Posts: 758

oldscoob - '87 subaru wagon gl/dr
90 day: 47.06 mpg (US)
Thanks: 21
Thanked 18 Times in 14 Posts
to argue the very thing that has many dynamics- left rights ups downs and even backwards...weight changes, gforce side winds front winds and brakes doing four different things. Accelerating, decelerating fwd , four wheel drive, auto and manual tranny, hubs or discs, independent suspension, solid axle...heat and torque for given engine curves as well as transaxles or axle enclosed. Electrical dissipation needed or not needed....

alloy or steel is the only question I answer. Keep the hubcaps. Alloys seem to be the champ on anything, unless they are badly made, and that is very rare today I would hope.

It seems comical in comparison to the engines to smooth wheels over a balanced part that needs to simply move every direction...when all engines have a wobbling idiot called a counterbalanced crankshaft. Fix the aero wheels, use a balanced engine. Watch the aero pursuits fade away into ridicule.
  Reply With Quote
Old 09-27-2008, 09:25 PM   #34 (permalink)
Old Retired R&D Dude
 
Join Date: May 2008
Location: Woburn Mass USA
Posts: 702

Little Red - '12 Toyota Prius c 2 Two
90 day: 57.82 mpg (US)

"Whitey" Bulger - '14 Toyota RAV4 LE
Thanks: 10
Thanked 18 Times in 17 Posts
My tape is still hanging in there.. And after seeing that chart, I'm going to keep my tape!
__________________
Cheers,
Rich

Current ride: 2014 RAV4 LE AWD (24 MPG)

Wife's Pizza Transporter
  Reply With Quote
Old 09-28-2008, 12:34 AM   #35 (permalink)
EcoModding Lurker
 
Join Date: Aug 2008
Location: Maryland
Posts: 92

Taurus - '99 Ford Taurus SE
90 day: 17.89 mpg (US)

Windstar1 - '97 Ford Windstar Cargo
90 day: 16.99 mpg (US)

Vulcan - '97 Kawasaki Vulcan 750
90 day: 45.96 mpg (US)

Suzuki - '09 Suzuki SX4 Technology AWD
90 day: 24.62 mpg (US)
Thanks: 0
Thanked 0 Times in 0 Posts
hmm im curious is it possible to put on a pizza pan thats bigger than the rim? so that it covers part of the tires?
maybe that will help reduce the gap of tire and rim.
  Reply With Quote
Old 09-28-2008, 07:40 AM   #36 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,513

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 52.71 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car - '14 Mitsubishi Mirage ES (base)
90 day: 60.16 mpg (US)
Thanks: 4,058
Thanked 6,957 Times in 3,602 Posts
Quote:
Originally Posted by Xringer View Post
And after seeing that chart, I'm going to keep my tape!
After seeing that chart, I'd be going for pizza pans.
__________________
Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
Mitsu mods: 70 MPG in my ecomodded, dirt cheap, 3-cylinder Mirage.
Ecodriving test: Manual vs. automatic transmission MPG showdown



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
Old 09-28-2008, 08:45 AM   #37 (permalink)
X-Frenchy: very
 
groar's Avatar
 
Join Date: Jun 2008
Location: Toulouse, France
Posts: 595

scenic - '01 renault scenic
90 day: 43.09 mpg (US)

megane - '97 renault megane classic
Diesel
90 day: 72.53 mpg (US)

dennisius - '06 Toyota Prius
Team Toyota
90 day: 69.27 mpg (US)
Thanks: 9
Thanked 34 Times in 23 Posts
Quote:
Originally Posted by tasdrouille View Post
If anyone still had doubts on that one...
Thanks a lot for these data.

What amazes me is the Cd difference with speed. I though that for cars' speeds (30-100 mph) the Cd was constant.

Is the cover has a better result because it's convex while tape masks are flat with some concave parts ?
In first case the air is moved away from wheel arch and turbulence is limited.

Quote:
Originally Posted by tasdrouille View Post
SAE paper 2007-01-1047 The Influence of Rotating Wheels on Total Road Load
I wished these documents were free... Wait, they have DRM... argh
SVOBoy, MetroMPG, why not add DRM protection on EM.com ? ;-)

Denis.
__________________
Save money & CO2 at home : http://ecorenovator.org/
Created and managed by the creators of http://ecomodder.com/
---
Earth and health are priceless, so are kilotank and AT-PZEV
Best Mégane tank: 1268.9mi @ 77.847 MPG(US)
2008/06-2011/10 saving:
  • 5725.5 kg CO2 (5342.6+382.9)
  • Diesel / Money: 42.17% = 2446.25€ = 3357.26$


---
megane : thread - kill switch.
  Reply With Quote
Old 09-28-2008, 09:55 AM   #38 (permalink)
Old Retired R&D Dude
 
Join Date: May 2008
Location: Woburn Mass USA
Posts: 702

Little Red - '12 Toyota Prius c 2 Two
90 day: 57.82 mpg (US)

"Whitey" Bulger - '14 Toyota RAV4 LE
Thanks: 10
Thanked 18 Times in 17 Posts
So, where can I find some 17" pizza pans with a 1/4" rim??
A perfect 17" would over-lap the gap, and a 0.20" to 0.30" would seal the gap nicely..

Since the center of my steel rims sticks out about 1/4" above the outer edges of the rim,
I'll need to over-lap a flap disc, or buy some 17" OD discs that are concave inside..


Hummm, Hard Aluminum Sloped Side 17" Pizza Pan S17 | Pans Screens Peels And Separators | Pizza items from Wasserstrom

Is ,18 GA ALUM thick enough for this app?
__________________
Cheers,
Rich

Current ride: 2014 RAV4 LE AWD (24 MPG)

Wife's Pizza Transporter
  Reply With Quote
Old 09-28-2008, 10:09 AM   #39 (permalink)
Master EcoModder
 
Join Date: Jul 2008
Location: united kingdom
Posts: 262

Tracy - '00 vauxhall corsa
Thanks: 0
Thanked 11 Times in 4 Posts
check out my wheel covers and skirts.

so far its really hard to claim a mpg gain. i think it is working tough. im getting 14.2miles per litre. this is close to my previous best and i was going slightly faster with less drafting.
Attached Thumbnails
Click image for larger version

Name:	Dsc00750.jpg
Views:	608
Size:	94.4 KB
ID:	1848   Click image for larger version

Name:	Dsc00751.jpg
Views:	588
Size:	80.7 KB
ID:	1849  
__________________
Nissan Leaf 24kwh. Average FE = 300mpg 3.6miles/kwh (@plug)
  Reply With Quote
Old 09-29-2008, 09:51 AM   #40 (permalink)
Old Retired R&D Dude
 
Join Date: May 2008
Location: Woburn Mass USA
Posts: 702

Little Red - '12 Toyota Prius c 2 Two
90 day: 57.82 mpg (US)

"Whitey" Bulger - '14 Toyota RAV4 LE
Thanks: 10
Thanked 18 Times in 17 Posts
Quote:
Originally Posted by achang1 View Post
hmm im curious is it possible to put on a pizza pan thats bigger than the rim? so that it covers part of the tires?
maybe that will help reduce the gap of tire and rim.

That's what I might try to do (if I buy some pizza pans).
Since the center of my rim sticks out about 1/4 inch.
That center area is where I would need to drill my mounting holes
and a flat disc would be floating about 1/4" above the outside edge of the rim.
So, if I could get the rolled edge of the pan to just kiss the rubber a bit,
I think that might be the perfect solution for my wheel..



What do you guys think about leaving the tape under the pizza pan?
Would it help?
The only problem I can think of, is loose tape balling up on one side
and making the wheel off-balance..

__________________
Cheers,
Rich

Current ride: 2014 RAV4 LE AWD (24 MPG)

Wife's Pizza Transporter
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com