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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 04-24-2008, 10:49 AM   #11 (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 2,588 Times in 1,555 Posts
Veeeeeeeery nice Tas, and yes thank you!

__________________
Current project: A better alternator delete
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 04-24-2008, 11:01 AM   #12 (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
One thing I noted though. In every single case where the frontal area was stated, the 0.81 correction factor on h * w you used gived an overly optimistic figure.

I recall reading a post by phil, must have been of of his aero seminars I'll have to search a bit, where he said to use 0.87 or 0.85, can't remember exactly.

Edit: it was
Quote:
Frontal area can be approximated by multiplying your vehicles width times its height,times 0.84.p
from Aerodynamics Seminar # 6 - by Phil Knox
__________________



www.HyperKilometreur.com - Quand chaque goutte compte...
  Reply With Quote
The Following User Says Thank You to tasdrouille For This Useful Post:
aerohead (07-29-2020)
Old 04-24-2008, 12:31 PM   #13 (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 2,588 Times in 1,555 Posts
Yeah, I noticed that too. I have updated the calculations to * .84. I have also added the bulk of the list you posted. I still have yet to go through the pdf.
__________________
Current project: A better alternator delete
  Reply With Quote
The Following User Says Thank You to Daox For This Useful Post:
aerohead (12-09-2021)
Old 04-24-2008, 12:36 PM   #14 (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
Just so you know, the ones I didn't post left in the pdf are mostly exotics.
__________________



www.HyperKilometreur.com - Quand chaque goutte compte...
  Reply With Quote
The Following User Says Thank You to tasdrouille For This Useful Post:
aerohead (12-09-2021)
Old 04-24-2008, 01:23 PM   #15 (permalink)
Hypermiler
 
PaleMelanesian's Avatar
 
Join Date: Dec 2007
Location: Texas
Posts: 2,321

PaleCivic (retired) - '96 Honda Civic DX Sedan
90 day: 69.2 mpg (US)

PaleFit - '09 Honda Fit Sport
Team Honda
Wagons
90 day: 44.06 mpg (US)
Thanks: 611
Thanked 434 Times in 284 Posts
There's a big list at wikipedia that can fill in some blanks.
__________________



11-mile commute: 100 mpg - - - Tank: 90.2 mpg / 1191 miles
  Reply With Quote
The Following User Says Thank You to PaleMelanesian For This Useful Post:
aerohead (08-06-2016)
Old 04-25-2008, 12:15 AM   #16 (permalink)
I'd rather be biking
 
boxchain's Avatar
 
Join Date: Feb 2008
Location: New Orleans, LA, US Minor Outlying Islands
Posts: 127

Lexie - '98 Honda Civic LX
90 day: 39.46 mpg (US)

Beater Hauler - '92 Isuzu Pickup

Rentaclipse - '08 Mitsubishi Eclipse ?
90 day: 28.28 mpg (US)

Fahrt - '83 BMW R80 ST
Thanks: 0
Thanked 4 Times in 4 Posts


Quote:
CHRYSLER PT CRUISER LIMITED EDITION 2000
Coefficient of drag: 0.40

FORD SVT MUSTANG COBRA 2003
Coefficient of drag: 0.38

MAZDA MIATA 1998
Coefficient of drag: 0.38

VOLKSWAGEN BEETLE 1999
Coefficient of drag: 0.38
__________________

My bike runs on dihydrogen monoxide.
I like to use these acronyms
  Reply With Quote
The Following User Says Thank You to boxchain For This Useful Post:
aerohead (08-06-2016)
Old 04-26-2008, 09:22 AM   #17 (permalink)
EcoModding Lurker
 
Join Date: Apr 2008
Location: SF Bay Area
Posts: 35
Thanks: 0
Thanked 3 Times in 3 Posts
A lot of the CdA figures floating around are estimates based on what the estimator thought the Cd might be. Many of the Wiki figures came from the mayfair company website which took a lot from an old version of the cartest program as well as (apparently) estimating a bunch. Accordingly it is hard to say how accurate these are.

I think it would be very helpful if there were some indication in the spreadsheet of where the data came from and whether it is a mfr's number, an independently tested number, or an estimate (and which part, Cd or A or both were estimated).

I'd be interested in knowing where the nology folks got their numbers from.

Without this info it seems like we're really not going to have very good data.

--Steve
  Reply With Quote
The Following User Says Thank You to SteveP For This Useful Post:
aerohead (08-06-2016)
Old 04-26-2008, 12:32 PM   #18 (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 2,588 Times in 1,555 Posts
Well, its definitly no Bible. But, its a heck of a lot better than nothing. Most of my info that I wasn't sure about I double checked against multipule sites. That being said I have used info from tons of different sites since I pulled most of the info from google. Frontal area is definitly estimated, so this really is a 'best guess'. No offense, I'm not going to go through and source every piece of info. The numbers will vary, but not by that much. You can see generally where your car sits against the pool of cars on the list. So, when someone comes on the site and says they have a frontal area of 19ft^2 you can know that is pretty small.
__________________
Current project: A better alternator delete
  Reply With Quote
The Following User Says Thank You to Daox For This Useful Post:
aerohead (08-06-2016)
Old 04-26-2008, 02:33 PM   #19 (permalink)
EcoModding Lurker
 
Join Date: Apr 2008
Location: SF Bay Area
Posts: 35
Thanks: 0
Thanked 3 Times in 3 Posts
Quote:
Originally Posted by Daox View Post
Well, its definitly no Bible. But, its a heck of a lot better than nothing. Most of my info that I wasn't sure about I double checked against multipule sites. That being said I have used info from tons of different sites since I pulled most of the info from google. Frontal area is definitly estimated, so this really is a 'best guess'. No offense, I'm not going to go through and source every piece of info. The numbers will vary, but not by that much. You can see generally where your car sits against the pool of cars on the list. So, when someone comes on the site and says they have a frontal area of 19ft^2 you can know that is pretty small.
Well, if the goal is just to "see generally where your car sits against the pool" then it might not be worth noting whether the data is wind tunnel or "eyeballed" (to take the extremes). I was just hoping that maybe a little more rigor could be injected by at least noting which numbers came from probably reputable sources vs from "unknown" sources.

Simply checking "multiple" sources doesn't do much--you would need to check independent sources--from what I've seen, a lot of the CdA info on the net is just repeated over and over with the result that very little is independent.

I think your frontal area is better than "a best guess". You've at least documented how the number was arrived at and if someone has a reason to use a different algorithm, they can do so since you provide the raw info (width, height).

--Steve
  Reply With Quote
The Following User Says Thank You to SteveP For This Useful Post:
aerohead (08-06-2016)
Old 04-26-2008, 04:19 PM   #20 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 16,286
Thanks: 24,410
Thanked 7,372 Times in 4,771 Posts
frontal area

Quote:
Originally Posted by tasdrouille View Post
One thing I noted though. In every single case where the frontal area was stated, the 0.81 correction factor on h * w you used gived an overly optimistic figure.

I recall reading a post by phil, must have been of of his aero seminars I'll have to search a bit, where he said to use 0.87 or 0.85, can't remember exactly.

Edit: it was from Aerodynamics Seminar # 6 - by Phil Knox
.84 was from "ancient" text,and Hucho's more current 0.81 multiplier reflects the industry use of more tumblehome in modern rooflines.I've glanced at a few semi-current CAR and DRIVER mags and they're reporting some "official" frontal areas that work out in the ninety-percent region,further confounding the likes of aero-modders in search of accutate quanta.Rats! I used to be more current,had subscriptions and everything.I got turned-off by all the paid advertising and let all my subscriptions lapse.Sorry!

__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
Reply  Post New Thread


Tags
cda list

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
List of Low Rolling Resistance Tires Daox EcoModding Central 57 05-13-2019 02:17 AM
What are your 2008 mod goals / wish list? MetroMPG EcoModding Central 45 01-02-2009 02:57 AM



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