Full boat tail on a Matrix

[Weather Spotter]

Update: test run

Today I needed a tube of caulk and some 1x2s to make a floor in the tail. My brother was heading off and so I had him follow me for a mile and watch the light snow flow off the tail. Then we swapped cars I and watched. I also took a video clip (not sure how to embed so here is the link) :

http://www.youtube.com/watch?v=0apq9kCL4Vs

Nothing fell off on my trip into town. I taped the gaps and the tape held just fine.

I also took some pics:








snow build up, so I think this area could use some help:


Ideas?

[Weather Spotter]

Well I did some more work on the tail. I closed up some gaps and made a floor that is even with the car floor.


I used the 1x2s I bought this morning to make the frame:


The I used some colorplast for the floor:


As it is now:

[Weather Spotter]

From my one short trip I watched my MPG's and it seems that I am 4-7MPG higher then I was last week when I drove the same route. This is very subjective testing (no wind today) roads have some snow etc...

[COcyclist]

It looks really good to me. Judging by the video, it looks like you have some turbulence down low but the top half appears to have attached flow. In the sunlight on the driver's side there is some airborne snow that breaks off cleanly at the transom. I believe you have significantly reduced the size of your trailing wake. Good news for hatchback or wagon owners.

[Weather Spotter]

So how do I fix the lower turbulence?

[NeilBlanchard]

Wheel strakes would likely help.

(click on image for link)

Darin tried them on his boattail:

(click on image for link)

[dennyt]

Love the interior shot of the extended floor! Any plans to sleep in it? I've had thoughts to this effect, making a boat tail and capitalizing on the extended sleeping volume at trailheads. But it's such a big project, and I parallel park in the city most days...

[euromodder]

Originally Posted by Weather Spotter

So how do I fix the lower turbulence?

Reducing the angle on the bottom maybe, as it seems rather steep.
Did you measure or calculate it ?

It'd require some serious redesigning to do that though.

[brucey]

Can't wait to see the ABA testing! Good idea with watching the snow bounce off the car. Pretty simple test. (: Looks to be working quite well.

[Weather Spotter]

Originally Posted by dennyt

Love the interior shot of the extended floor! Any plans to sleep in it? I've had thoughts to this effect, making a boat tail and capitalizing on the extended sleeping volume at trailheads. But it's such a big project, and I parallel park in the city most days...

I have thought of it before, say on long trips pull off in a rest stop and sleep. I have not done it but now I have the needed length I can also watch stars out of my new moon roof.

@ euromodder
I want to reduce the turbulence but I think that NeilBlanchard is on the right track. The wheels seem to be making a vortex. In the middle the bottom still has attached flow. The trick will be making the mini boat tails for the tires and still be able to go through 8" of snow and debris on the road.

MetroMPG's ones look too big any ideas on how to?