View Single Post
Old 04-18-2015, 11:36 AM   #49 (permalink)
MetroMPG
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,534

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

MPGiata - '90 Mazda Miata
90 day: 54.46 mpg (US)

Appliance car Mirage - '14 Mitsubishi Mirage ES (base)
90 day: 57.73 mpg (US)
Thanks: 4,082
Thanked 6,979 Times in 3,614 Posts
Quote:
Originally Posted by aerohead View Post
...Hucho have all warned about limited results from drag reduction if the engine could not be maintained at a constant load to maintain BSFC.
That could well be it.

And maybe it's possible I just haven't done the "drag reduction" part of the equation properly, and the tail isn't optimal.

Mulling over the disappointing results, when I look back at the amount of turbulence that tuft testing revealed on the sides of the tail (see my long Civic build thread for details, starting at #226) I wonder if most of the side of the tail is just sitting in turbulence & separation, contributing little to drag reduction.

Yesterday I was ready to call it a day and consign this experiment to the recycling bin. But I've had a change of heart: the tail will get some surgery to relax the side angles, plus a smallish spoiler on the top surface. And I'll re-test to see if it makes any difference.

I'll also post back with details (numbers, graph) of the first test later today.
__________________
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
The Following User Says Thank You to MetroMPG For This Useful Post:
mikeyjd (04-18-2015)