Stainless Kammback for Previa.

[elhigh]

The Previa (my wife hates that name, it always makes her think of placenta previa, which is bad if you're pregnant) was always kind of a pig at the pump in spite of the shape. You've dragged it into not-eligible-for-clunker-cash territory.

Dang.

Mods in stainless and no new holes, you are an ecomodding monster.

[orange4boy]

More mock ups. I am trying to decide if I want a plumb line at the back or an angled line to correspond to the angled back of the Previa. The angled back looks better, I think but it makes the whole thing a bit longer than I was shooting for. The bottom picture shows the two possibilities I am contemplating. It may come down to the size of the lexan pieces I have.







I found the anodized aluminium extrusions at Ikea in the as-is section for a buck each. Ecomodding score!

[Daox]

OOOoooooooooh.

[Cd]

Wow.
That is looking great so far.

[Christ]

Plumb line... To me, anyway.

[orange4boy]

Plumb it is.

I had a piece of 1/8" plexi around so the end is filled with the table saw shaped piece. The sides are black coroplast for now but I think I will pop in the twin wall lexan when I get some more. The bottom is not filled yet but I have some "clear" coroplast which will probably fill that function

Construction details... Drilled and tapped for 8-32 pan head stainless machine screws.



I'm not totally satisfied with the look of this. I think it needs a radius at the end at the top corners and along the lexan seam. I can fix this later. I also want to make a side detail that reflects curves of the stainless scimitar panels.



There she is 90% done and driveable. As a fun design accident, the trailing edge has a trip angle to it.



Wake area reduction is approximately 7 sq feet. from about 28 to 21 so almost 1/3 reduction, if my math is right. It sure will be interesting to see how that feels at highway speed. Who knows what the un-modded bottom half does to the air. We shall see.

[aerohead]

Originally Posted by orange4boy

Plumb it is.

I had a piece of 1/8" plexi around so the end is filled with the table saw shaped piece. The sides are black coroplast for now but I think I will pop in the twin wall lexan when I get some more. The bottom is not filled yet but I have some "clear" coroplast which will probably fill that function

Construction details... Drilled and tapped for 8-32 pan head stainless machine screws.



I'm not totally satisfied with the look of this. I think it needs a radius at the end at the top corners and along the lexan seam. I can fix this later. I also want to make a side detail that reflects curves of the stainless scimitar panels.



There she is 90% done and driveable. As a fun design accident, the trailing edge has a trip angle to it.



Wake area reduction is approximately 7 sq feet. from about 28 to 21 so almost 1/3 reduction, if my math is right. It sure will be interesting to see how that feels at highway speed. Who knows what the un-modded bottom half does to the air. We shall see.

Without the lower half she's an unknown quantity.I suspect some trailing vortices as with two points of separation,at different velocities and pressures,it's kind of a setup for that.Does seem like the wake will be positively modified though.Best to you with it and let us know when you get some numbers.

[alohaspirit]

once again, stellar stuff right there


id be interested in knowing:


1. how much length does the tail add?

2. how is visibility?

3. mpg gain (naturally)

4. what police have to say about it?

(i know some get curious and ask, is why)

[orange4boy]

Thanks for all the everyone...

Alohaspirit,

Tail overhangs the bumper a little over a foot. The tailgate does not stay open without a prop now I probably need new ones anyhow.)

My rear window is cut by about 2/3. I can still see cars when they are about 3 lengths away. The lexan breaks up the light a bit but I can still tell how close they are through it.

MPG gain is unknown until I can do some highway runs. I doubt that it will affect local island driving because it's mostly hills and I rarely get above 35mph.

I have not encountered the Mounties in the van yet. I may be a little out of the regs with it because it blocks the tail lights at high angles. I will add some extra lights soon. I need the plugs and some LEDs. I'm hoping to find a strip of red for the middle stoplight.

I like this angle best: That's what the rigs will see when they haul ass up behind me.

[cfg83]

orange4boy -

Originally Posted by orange4boy

...



Wake area reduction is approximately 7 sq feet. from about 28 to 21 so almost 1/3 reduction, if my math is right. It sure will be interesting to see how that feels at highway speed. Who knows what the un-modded bottom half does to the air. We shall see.

From the reflection it looks like you made a clear cover for the vertical rear component. Could you have gotten away with not having it?

CarloSW2