Starting on belly pan, inadvertently discovered benefits of boat tail

[Ecky]

A few days ago I bought a few 3'x6' sheets of coroplast to make a belly pan with, and decided to visit my father's to make a weekend out of it. We're going to work out a way to insulate the exhaust and make some bracing. I loaded it up into my car by pinching it in the back window like so:





Normally, I can get 37MPG cruising at 65MPH, 33 at 70, and ~30 at 75. Even though the coroplast isn't flush with the roof, and isn't quite as high as it needs to be above the trunk (I still had some turbulence, should be about 3" higher I believe), I had a significant improvement!

92 miles later:



I've never had more than 37MPG on an extended trip. Weather was in the 50's and a bit wet, so probably not even ideal conditions. 37 -> 42.5 is a 15% improvement. I'm seriously considering constructing a detachable tail with feet to hold it above the truck lid for road trips now, and am excited to see what the combination of boat tail and belly pan will provide.

[Joggernot]

Cheapest effective boat tail I've seen on this forum. Nice discovery! Maybe add a tall lip to bring the front even with the roof and tape it to the trunk. That way you still have access to the trunk.

Don't know the laws about having a working rear window, though.

[jedi_sol]

Let us know your boat tail results. I tried designing a kamm back on my old del sol, but it didn't show any improvement so I didn't pursue it. But then again my design could've been flawed

[KrautBurner]

that is a pretty cool way too fall into a cool mod

btw,
where do you get the coroplast?
how thick do you get? 4mm?

[Ecky]

4mm, was $14 for a 6'x3' sheet at Home Depot.

[KrautBurner]

Originally Posted by Ecky

4mm, was $14 for a 6'x3' sheet at Home Depot.

cool,

I may look into this after I get a couple tanks thru the old Chick Magnet (Prius)



btw,

how do you get that Sig?
http://ecomodder.com/forum/fe-graphs/sig5723a.png

[Ecky]

I believe this is how I did it:

http://ecomodder.com/forum/showthrea...ure-20941.html

It's been a while though.