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Old 03-05-2015, 11:29 AM   #2 (permalink)
MetroMPG
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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
Step 1: Needs More Prius. AKA: Notchback to Kammback

Construction details, part 1: Kammback transformation...

Before a tapered tail can do its drag-reducing aerodynamic magic, we want to deliver clean, attached airflow to the back of the car. That's a problem with a notchback (a.k.a. 3-box) design, because airflow typically gets messy behind the rear glass:



Of course, the flow over the Civic's rear glass & trunk isn't as bad as this exaggerated image. How do I know? I taped yarn tufts on the rear window and went for a drive.





Tuft testing result: I was slightly surprised to see separation/recirculation (red/orange area), but it's there. Even though the Civic's rear glass is laid way back and the deck is fairly high, it's obviously stil too "fast" to keep attached flow.

Solution: A MORE PRIUS-Y PROFILE, PLEASE!








HOW THE HECK DO I SEE OUT THE BACK?

It's got a rear plexiglass window. Also, I built in a high-center-mounted third brake light:





Looks neat, eh? No, the snow isn't sitting on cardboard. It's all wrapped in heat-shrunk plastic at this point.

And I gorilla taped the whole thing to the back of the car.

So, no, that means I can't open the trunk anymore. But I can still access it from the cabin, through the folding rear seatbacks. I can also get the spare & tools out that way if I need to.

(For full details of the Kammback construction start at post #173 in the kitchen-sink-megathread.)
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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
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BamZipPow (03-12-2015), California98Civic (03-18-2015), Daox (03-12-2015), ECONORAM (06-18-2015), NeilBlanchard (03-18-2015), OG VX (03-16-2015)