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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 01-02-2013, 05:01 AM   #31 (permalink)
Southern Squidbillie
 
Join Date: Aug 2012
Location: Heart of Dixie
Posts: 97
Thanks: 50
Thanked 26 Times in 22 Posts
May be cosmetics, but not economic decision

Quote:
Originally Posted by F8L View Post
I'm really curious to see how all of this pans out, particularly anything related to the wheels and the high offset (sunken in) effect. So many Prius owners opt for wider wheels with a lower offset. I am concerned about the effect the increased width and decreased offset will have on aerodynamics. If you push the wheel out so it is flush with the body line is this going to increase turbulence?
i think it will increase turbulence, but even if it could somehow decrease turbulence slightly, what would be the payback time of additional fuel savings to offset the cost of the new wheels? Seems like a wheel skirt would have more aero benefit and cost less...

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 01-02-2013, 05:06 AM   #32 (permalink)
Southern Squidbillie
 
Join Date: Aug 2012
Location: Heart of Dixie
Posts: 97
Thanks: 50
Thanked 26 Times in 22 Posts
Hey Ryan, have you looked at comparing the aero template to your car--what is the angle of the rear glass with respect to the horizontal of the vehicle and the distance back from the roof apex?
  Reply With Quote
Old 01-02-2013, 08:56 AM   #33 (permalink)
Administrator
 
Daox's Avatar
 
Join Date: Dec 2007
Location: Germantown, WI
Posts: 11,203

CM400E - '81 Honda CM400E
90 day: 51.49 mpg (US)

Daox's Grey Prius - '04 Toyota Prius
Team Toyota
90 day: 49.53 mpg (US)

Daox's Insight - '00 Honda Insight
90 day: 64.33 mpg (US)

Swarthy - '14 Mitsubishi Mirage DE
Mitsubishi
90 day: 56.69 mpg (US)

Daox's Volt - '13 Chevrolet Volt
Thanks: 2,501
Thanked 2,585 Times in 1,553 Posts
Quote:
Originally Posted by ryannoe View Post
No testing with video or yarn was completed today. I did drive the Prius in the rain and during stop lights, rain gathered on the back glass. After accelerating to 60 mph (power mode because I didn't want them to collect into jumbo drops and let gravity do all of the work) the droplets were unscathed and BARELY pushing their way to the rear. After my 6 mile run, there were still roughly half of the droplets attached to the window. I shouldn't say this, but I was pretty much watching those droplets the entire drive

You guys had me doubting my initial thoughts of the separated flow, but now I'm more confident that the flow has separated. Hope to have something for you soon.

-Ryan
It would be interesting to see what happens to the tuffs if they were raised say 1/4" or so. I wonder how thick your boundry layer is.
__________________
Current project: A better alternator delete
  Reply With Quote
Old 01-02-2013, 10:15 AM   #34 (permalink)
Not Ordinary Engineering
 
Join Date: May 2011
Location: Alabama
Posts: 57
Thanks: 9
Thanked 27 Times in 14 Posts
Quote:
Originally Posted by kennybobby View Post
Hey Ryan, have you looked at comparing the aero template to your car--what is the angle of the rear glass with respect to the horizontal of the vehicle and the distance back from the roof apex?
KennyBobby - What aero template?

Quote:
It would be interesting to see what happens to the tuffs if they were raised say 1/4" or so. I wonder how thick your boundry layer is.
Daox - I had a similar idea. More coming soon on it.
  Reply With Quote
Old 01-02-2013, 10:48 AM   #35 (permalink)
F8L
EcoModding Apprentice
 
F8L's Avatar
 
Join Date: Oct 2011
Location: Sacramento, CA
Posts: 152

F8L's 2012 Prius - '12 Toyota Prius Three with Solar Roof
90 day: 62.14 mpg (US)
Thanks: 15
Thanked 34 Times in 25 Posts
Quote:
Originally Posted by kennybobby View Post
i think it will increase turbulence, but even if it could somehow decrease turbulence slightly, what would be the payback time of additional fuel savings to offset the cost of the new wheels? Seems like a wheel skirt would have more aero benefit and cost less...
I should have stated the new wheels are not for fuel economy. They are added for looks and or handling. I'm interested in the negative impact of offset and width if all other factors are kept constant.
__________________
2012 Prius Three with Solar Roof - Blizzard Pearl w/dark gray interior: Prius Plug-In 15" Wheels | Michelin Energy Saver A/S 195/65/15 tires | TRD Lowering Springs | WeatherTech FloorLiners | Scangauge II | Morimoto/DDM HIDs 5000K | Clazzio Leather Seat Covers | Best Tank: 71.7mpg@702miles | Best Trip: 95.9mpg@233miles
  Reply With Quote
Old 01-02-2013, 10:52 AM   #36 (permalink)
Southern Squidbillie
 
Join Date: Aug 2012
Location: Heart of Dixie
Posts: 97
Thanks: 50
Thanked 26 Times in 22 Posts
hey Ryan,

http://ecomodder.com/forum/showthrea...ion-21952.html

and

http://ecomodder.com/forum/showthrea...rt-c-9287.html
  Reply With Quote
Old 01-02-2013, 11:14 PM   #37 (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 F8L View Post
I should have stated the new wheels are not for fuel economy. They are added for looks and or handling. I'm interested in the negative impact of offset and width if all other factors are kept constant.
Maybe of interest:


Prius 15's are better than aftermarket 17's! (Wrong wheels/tires can wreck your MPG) - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com
__________________
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 01-03-2013, 12:42 AM   #38 (permalink)
F8L
EcoModding Apprentice
 
F8L's Avatar
 
Join Date: Oct 2011
Location: Sacramento, CA
Posts: 152

F8L's 2012 Prius - '12 Toyota Prius Three with Solar Roof
90 day: 62.14 mpg (US)
Thanks: 15
Thanked 34 Times in 25 Posts
Thanks. I've been testing the effects of 17" wheels/tires on mpg since I bought my first Prius in 2005. There is ALWAYS a negative hit associated with upsizing. My question on the aero effects of such a change or that of decreased offset was an effort to try and figure out all of the variables that go into this fuel economy loss so we can try to reduce it.
__________________
2012 Prius Three with Solar Roof - Blizzard Pearl w/dark gray interior: Prius Plug-In 15" Wheels | Michelin Energy Saver A/S 195/65/15 tires | TRD Lowering Springs | WeatherTech FloorLiners | Scangauge II | Morimoto/DDM HIDs 5000K | Clazzio Leather Seat Covers | Best Tank: 71.7mpg@702miles | Best Trip: 95.9mpg@233miles
  Reply With Quote
Old 01-03-2013, 12:35 PM   #39 (permalink)
Southern Squidbillie
 
Join Date: Aug 2012
Location: Heart of Dixie
Posts: 97
Thanks: 50
Thanked 26 Times in 22 Posts
Hey Metro,

Would you please explain the meaning of the presence or absence of snow patches on the probe?
  Reply With Quote
Old 01-04-2013, 12:26 AM   #40 (permalink)
Not Ordinary Engineering
 
Join Date: May 2011
Location: Alabama
Posts: 57
Thanks: 9
Thanked 27 Times in 14 Posts
2012 Toyota Prius Aero Test Data - 1/3/2012

Hey all,

No fun tuft videos to watch today but I ran some drag test coast downs today.

I want to slowly swing everyone's opinion over to flat plate drag so I'm going to give you guys that value as much as possible to get you familiar with it

2012 Toyota Prius (no mods) FPD: 0.6885 m^2

Rolling Resistance with factory tires: 0.0116

or if you're stubborn --- Cd: 0.28 with a frontal area of 2.39 m^2

(remember FPD is the same as CdA)

The frontal area was measured by finding a picture from the web and using GIMP to color it in and using histogram to count the pixels. I used the manufacturer's height to determine pixel size per square inch of area.

Since FPD doesn't care what the frontal area is, it's my preferred method.

Have a great night!

-Ryan

  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