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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 05-16-2008, 09:14 PM   #1 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 21,126

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

MPGiata - '90 Mazda Miata
90 day: 53.67 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
90 day: 73.57 mpg (US)
Thanks: 2,917
Thanked 5,764 Times in 2,981 Posts
See also: http://ecomodder.com/forum/showthrea...fect-6381.html

---

Here's the skinny on an A-B-A test @ 90 km/h on the end of the roof of a 2006 Toyota Corolla 4-door sedan automatic.



Results in mpg (US), averages of mulitple bi-directional runs:

A - 48.9 - no airtabs

B - 48.6 - airtabs

A - 48.5 - no airtabs


I'll post up the details later.

Update May 17/08:

Raw data:

Code:
    West    East    Avg.
A    49.1    49.3    49.2
A    49    48.4    48.7
A    48.2    48.8    48.5
A    49.1    49    49.05

B    48.2    48.9    48.55
B    47.8    48.8    48.3
B    48.3    49.1    48.7
B    48.5    49    48.75

A    48.5    48.5    48.5
A    47.8    49    48.4
A    48    49    48.5
Avg. of all A runs (7): 48.69 mpg (US)
Standard deviation of avg. of all A runs: 0.31 mpg (US)

Avg. of all B runs (4): 48.58 mpg (US)
Standard deviation of avg. of all B runs: 0.20 mpg (US)

The distribution of the data seems pretty tight. I have a good test route (next to no traffic) & had nearly ideal weather (next to no breeze).

Update - August 18/08


__________________
Latest mods test: 15 mods = 15% MPG improvement: A-B test, 2007 Honda Civic 1.8L, 5-speed
Ecodriving test:
Manual vs. automatic transmission MPG showdown: Nissan Micra 1.6L



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
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 05-16-2008, 10:19 PM   #2 (permalink)
MechE
 
Join Date: Dec 2007
Location: Bay Area
Posts: 1,151

The Miata - '01 Mazda MX-5 Miata
Thanks: 0
Thanked 20 Times in 17 Posts
Metro, I don't know if you plan on including it... But the standard deviation for A and B would be awesome for something like this
__________________
Cars have not created a new problem. They merely made more urgent the necessity to solve existing ones.
  Reply With Quote
Old 05-16-2008, 10:24 PM   #3 (permalink)
Master EcoModder
 
Join Date: Mar 2008
Location: USA
Posts: 560
Thanks: 1
Thanked 67 Times in 53 Posts
Well, Tre, with results like these, I hope you made your VGs out of cheap plastic.

Tried them on you HPV streamliner yet?
  Reply With Quote
Old 05-17-2008, 02:55 PM   #4 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 21,126

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

MPGiata - '90 Mazda Miata
90 day: 53.67 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
90 day: 73.57 mpg (US)
Thanks: 2,917
Thanked 5,764 Times in 2,981 Posts
Raw data:

Code:
    West    East    Avg.
A    49.1    49.3    49.2
A    49    48.4    48.7
A    48.2    48.8    48.5
A    49.1    49    49.05

B    48.2    48.9    48.55
B    47.8    48.8    48.3
B    48.3    49.1    48.7
B    48.5    49    48.75

A    48.5    48.5    48.5
A    47.8    49    48.4
A    48    49    48.5
Avg. of all A runs (7): 48.69 mpg (US)
Standard deviation of avg. of all A runs: 0.31 mpg (US)

Avg. of all B runs (4): 48.58 mpg (US)
Standard deviation of avg. of all B runs: 0.20 mpg (US)

The distribution of the data seems pretty tight. I have a good test route (next to no traffic) & had nearly ideal weather (next to no breeze).

I'm waiting (weather) for the opportunity to also tuft test the back window/trunk of this car with & without the VG's. Hopefully this weekend.
__________________
Latest mods test: 15 mods = 15% MPG improvement: A-B test, 2007 Honda Civic 1.8L, 5-speed
Ecodriving test:
Manual vs. automatic transmission MPG showdown: Nissan Micra 1.6L



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 05-17-2008, 03:00 PM   #5 (permalink)
EcoModding Apprentice
 
Join Date: Apr 2008
Location: So. IN.
Posts: 187

Blue - '77 Chevy P/U
Thanks: 0
Thanked 1 Time in 1 Post
can you add pics ???
  Reply With Quote
Old 05-17-2008, 03:01 PM   #6 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 21,126

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

MPGiata - '90 Mazda Miata
90 day: 53.67 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
90 day: 73.57 mpg (US)
Thanks: 2,917
Thanked 5,764 Times in 2,981 Posts
I'll get some when tuft testing.
__________________
Latest mods test: 15 mods = 15% MPG improvement: A-B test, 2007 Honda Civic 1.8L, 5-speed
Ecodriving test:
Manual vs. automatic transmission MPG showdown: Nissan Micra 1.6L



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 05-17-2008, 03:02 PM   #7 (permalink)
EcoModding Apprentice
 
Join Date: Apr 2008
Location: So. IN.
Posts: 187

Blue - '77 Chevy P/U
Thanks: 0
Thanked 1 Time in 1 Post
Quote:
Originally Posted by MetroMPG View Post
I'll get some when tuft testing.
cool ,,thanks
  Reply With Quote
Old 05-17-2008, 04:30 PM   #8 (permalink)
EcoModding Apprentice
 
Join Date: Jan 2008
Location: Chicagoland
Posts: 204

- - '10 Toyota Prius III w/Navi
Thanks: 4
Thanked 11 Times in 11 Posts
Hi Metro,

How about trying them at the front of the roof, about 6 inches back from the windshield, or even right at the top of the windshield? That is more in line with aircraft applications.

It looks like where you had them they were completely within the boundray layer and thus there was little impact.

Aerohead was saying that the flow is seperating there already. So, this makes sense. The idea at putting them forward, is that they may keep the cross section of the turbulent flow smaller.

On an 18 wheeler, my guess is that the flow is pretty laminar by the time it gets to the rear of the truck. That is, the turbulent effects have decayed, which then start up again behind the truck. I base this on driving next to trucks and watching my Prius mileage indicator. Cars are not long enough for these to have an effect on the roof above the C pillar, I do not think. Even though that is where the EVO uses them. The EVO has such a highly angled rear window, it may be pulling the bounadary layer on the roof down.
  Reply With Quote
Old 05-17-2008, 05:59 PM   #9 (permalink)
Legend in my own mind
 
trikkonceptz's Avatar
 
Join Date: Apr 2008
Location: Homestead, Fl.
Posts: 927

Evil Pumpkin - '08 Scion xD RS 1.0 #1633
90 day: 35.45 mpg (US)

Silent Silver Killer - '10 Honda Insight EX
90 day: 51.5 mpg (US)
Thanks: 2
Thanked 13 Times in 12 Posts
I found this link in an unrelated search, I hope it will help you guys on the subject .. Interesting stuff


http://www.mitsubishi-motors.com/cor...004/16E_03.pdf
__________________
Thx NoCO2; "The biggest FE mod you can make is to adjust the nut behind the wheel"

I am a precisional instrument of speed and aeromatics
If your knees bent in the opposite direction......what would a chair look like???





  Reply With Quote
Old 05-17-2008, 09:51 PM   #10 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 21,126

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

MPGiata - '90 Mazda Miata
90 day: 53.67 mpg (US)

Winter beater Metro - '00 Chevrolet Metro
90 day: 73.57 mpg (US)
Thanks: 2,917
Thanked 5,764 Times in 2,981 Posts
Hi Donee -

The placement of the VG's was based on the PDF that trikkoncept linked. Have a look.

Flow typically separates at the trailing edge of the roof on 3-box vehicles, so that's where VG's would theoretically help most.

That said, also note that the Mistu engineers themselves managed only a 0.006 change in Cd in their application. So even if they were helping, I would have been surprised to see any significant change in the Corolla results.

Renault also used trailing roof edge VG's on their Michelin Challenge Bibendum Logan sedan: http://forum.ecomodder.com/showthrea...179.html?t=179

It's quite possible that the Corolla's rear glass angle is already close to optimal, so wouldn't benefit much anyway. Tuft testing will help figure that out.

__________________
Latest mods test: 15 mods = 15% MPG improvement: A-B test, 2007 Honda Civic 1.8L, 5-speed
Ecodriving test:
Manual vs. automatic transmission MPG showdown: Nissan Micra 1.6L



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
The Following User Says Thank You to MetroMPG For This Useful Post:
AeroModder (04-22-2010)
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Vortex generators - where's the solid data for hatchback/van benefits? MetroMPG Aerodynamics 70 03-14-2012 12:25 PM
Belly pan or vortex generators? edbso Aerodynamics 125 02-22-2011 12:50 PM
Honda's OEM vortex generators ... on the Ridgeline pickup mirrors MetroMPG Aerodynamics 21 12-06-2008 01:09 PM
Review: 2009 Toyota Corolla LE (37.9 MPG) RH77 General Efficiency Discussion 22 05-09-2008 04:55 PM
Win an EM Sticker: guess Dad's mileage (Toyota Corolla automatic). Ends Jan 13. MetroMPG Hypermiling / EcoDriver's Ed 51 02-07-2008 09:02 AM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com