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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 01-25-2012, 02:38 PM   #21 (permalink)
Cyborg ECU
 
California98Civic's Avatar
 
Join Date: Mar 2011
Location: Coastal Southern California
Posts: 6,237

Black and Green - '98 Honda Civic DX Coupe
Team Honda
90 day: 66.42 mpg (US)

Black and Red - '00 Nashbar Custom built eBike
90 day: 3671.43 mpg (US)
Thanks: 2,356
Thanked 2,128 Times in 1,443 Posts
Quote:
Originally Posted by ConnClark View Post
The best coast down tests are done by coasting down a hill from a chalk starting line. That way you can always have the exact same energy to deal with for each test.
I have the perfect hill. A mile and a quarter or more, no lights, no stops. Right next to campus. I'll mark a spot. Record speed at a specific second spot. A "coast-up" test. I'll do that first, being the less costly option in terms of time and gas.

Quote:
Originally Posted by Frank Lee View Post
I ran skirts over a year. Results didn't show up in tank-to-tank records. Skirts are now off. I prefer to be able to check and air up the rear tires without the hassle.
I hear you, Frank. But I can deal with the slight hassle of the air pressure check, and I actually like the look a lot. As long as they are not a net loss aerodynamically, I'll keep at it until I have a good looking, well-fabricated pair of 'em.

__________________
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.



  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 01-25-2012, 04:10 PM   #22 (permalink)
DieselMiser
 
ConnClark's Avatar
 
Join Date: Jun 2008
Location: Richland,WA
Posts: 967

Das Schlepper Frog - '85 Mercedes Benz 300SD
90 day: 23.23 mpg (US)

Gentoo320 - '04 Mercedes C320 4Matic
90 day: 22.44 mpg (US)
Thanks: 46
Thanked 227 Times in 156 Posts
Quote:
Originally Posted by California98Civic View Post
I have the perfect hill. A mile and a quarter or more, no lights, no stops. Right next to campus. I'll mark a spot. Record speed at a specific second spot. A "coast-up" test. I'll do that first, being the less costly option in terms of time and gas.
For accuracy it would be best to start from a dead stop and coast to a dead stop and look at the distance. Do maybe 3 test for each configuration.
__________________
  Reply With Quote
Old 01-25-2012, 06:17 PM   #23 (permalink)
EcoModding Apprentice
 
Join Date: Mar 2008
Location: Cold Lake, AB
Posts: 100

Alexa - '07 Honda Civic LX
90 day: 38.32 mpg (US)

FX - '06 Infiniti FX35
90 day: 17.98 mpg (US)

Priya - '03 Saturn Ion 3
90 day: 27.81 mpg (US)
Thanks: 1
Thanked 6 Times in 5 Posts
but starting from a dead stop would require a large hill to get speed up enough to affect aero.
__________________

  Reply With Quote
Old 01-25-2012, 07:57 PM   #24 (permalink)
Cyborg ECU
 
California98Civic's Avatar
 
Join Date: Mar 2011
Location: Coastal Southern California
Posts: 6,237

Black and Green - '98 Honda Civic DX Coupe
Team Honda
90 day: 66.42 mpg (US)

Black and Red - '00 Nashbar Custom built eBike
90 day: 3671.43 mpg (US)
Thanks: 2,356
Thanked 2,128 Times in 1,443 Posts
Quote:
Originally Posted by ConnClark View Post
For accuracy it would be best to start from a dead stop and coast to a dead stop and look at the distance. Do maybe 3 test for each configuration.
Rolling to a stop from highway speeds won't be an option around here. Too many lights and stop signs. What I have is a hill that gets me from a total stop to 55mph in 0.5 miles. That's 10mph above the posted speed limit with half a mile of hill still to go. I would have to brake to avoid going farther beyond the speed limit. That's not good enough? I figure I pick a spot and compare the speeds I reach by the time I get there. That's too inaccurate?
__________________
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.



  Reply With Quote
Old 01-25-2012, 08:40 PM   #25 (permalink)
EcoModding Apprentice
 
Join Date: Mar 2008
Location: Cold Lake, AB
Posts: 100

Alexa - '07 Honda Civic LX
90 day: 38.32 mpg (US)

FX - '06 Infiniti FX35
90 day: 17.98 mpg (US)

Priya - '03 Saturn Ion 3
90 day: 27.81 mpg (US)
Thanks: 1
Thanked 6 Times in 5 Posts
I've never done a coast test before but 55mph should be fast enough to notice a change.
__________________

  Reply With Quote
Old 01-26-2012, 02:00 PM   #26 (permalink)
DieselMiser
 
ConnClark's Avatar
 
Join Date: Jun 2008
Location: Richland,WA
Posts: 967

Das Schlepper Frog - '85 Mercedes Benz 300SD
90 day: 23.23 mpg (US)

Gentoo320 - '04 Mercedes C320 4Matic
90 day: 22.44 mpg (US)
Thanks: 46
Thanked 227 Times in 156 Posts
Quote:
Originally Posted by California98Civic View Post
Rolling to a stop from highway speeds won't be an option around here. Too many lights and stop signs. What I have is a hill that gets me from a total stop to 55mph in 0.5 miles. That's 10mph above the posted speed limit with half a mile of hill still to go. I would have to brake to avoid going farther beyond the speed limit.
Start lower down the hill then.
Quote:
That's not good enough? I figure I pick a spot and compare the speeds I reach by the time I get there. That's too inaccurate?
Yes that is too inaccurate. It involves too much human interaction and relies on your ability to time it right.

If want the test to prove conclusively that you can go farther on the same amount of energy then you want to measure it directly by going farther on the same amount of energy.
__________________
  Reply With Quote
The Following User Says Thank You to ConnClark For This Useful Post:
FXSTi (01-26-2012)
Old 01-26-2012, 02:46 PM   #27 (permalink)
(:
 
Frank Lee's Avatar
 
Join Date: Jan 2008
Location: up north
Posts: 12,761

Blue - '93 Ford Tempo
Last 3: 27.29 mpg (US)

F150 - '94 Ford F150 XLT 4x4
90 day: 18.5 mpg (US)

Sport Coupe - '92 Ford Tempo GL
Last 3: 69.62 mpg (US)

ShWing! - '82 honda gold wing Interstate
90 day: 33.65 mpg (US)

Moon Unit - '98 Mercury Sable LX Wagon
90 day: 21.24 mpg (US)
Thanks: 1,584
Thanked 3,546 Times in 2,215 Posts
In college I did on the road aero experiments and testing. I found that a gust of wind, passing truck, anything could screw up the results. Statistically, one needs to make hundreds of runs to mitigate environmental effects. Good luck.
__________________


  Reply With Quote
Old 01-26-2012, 04:18 PM   #28 (permalink)
EcoModding Lurker
 
Blacktree's Avatar
 
Join Date: Dec 2011
Location: Florida
Posts: 37

The SaTurd - '01 Saturn SL1
90 day: 34.37 mpg (US)
Thanks: 4
Thanked 4 Times in 4 Posts
Thumbs up

Quote:
Originally Posted by California98Civic View Post
Rolling to a stop from highway speeds won't be an option around here. Too many lights and stop signs. What I have is a hill that gets me from a total stop to 55mph in 0.5 miles. That's 10mph above the posted speed limit with half a mile of hill still to go. I would have to brake to avoid going farther beyond the speed limit. That's not good enough? I figure I pick a spot and compare the speeds I reach by the time I get there. That's too inaccurate?
That sounds perfect to me!

But like Mr Lee suggested, it may take several runs to get a good sample group.

On a side note, you could use a stop-watch to measure the amount of time it takes to go from zero to the speed limit, to avoid law enforcement issues.
  Reply With Quote
Old 01-26-2012, 04:45 PM   #29 (permalink)
My way is the low way
 
Superturnier's Avatar
 
Join Date: Jun 2009
Location: Finland
Posts: 64

MyoldFord - '65 Ford Taunus 20M Turnier
90 day: 27.59 mpg (US)

Plastic Spaceship - '94 Renault Espace
90 day: 24.03 mpg (US)

Sussu - '82 Suzuki Alto
Thanks: 4
Thanked 17 Times in 8 Posts
I would think that, the higher the speed, the more you can see differences in aero mods?
Yes, I know that an true ecomodder don't want to ruin any tank mileage by some high speed testing.
__________________

Summer vehicle


My dad's tire pressure is much higher than your dad's!
  Reply With Quote
Old 01-26-2012, 05:17 PM   #30 (permalink)
DieselMiser
 
ConnClark's Avatar
 
Join Date: Jun 2008
Location: Richland,WA
Posts: 967

Das Schlepper Frog - '85 Mercedes Benz 300SD
90 day: 23.23 mpg (US)

Gentoo320 - '04 Mercedes C320 4Matic
90 day: 22.44 mpg (US)
Thanks: 46
Thanked 227 Times in 156 Posts
Quote:
Originally Posted by Frank Lee View Post
In college I did on the road aero experiments and testing. I found that a gust of wind, passing truck, anything could screw up the results. Statistically, one needs to make hundreds of runs to mitigate environmental effects. Good luck.
Maybe he could do it at 3am when the winds are calm and there is no traffic.

__________________
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com