Extending the Decklid (Toyota Echo)

[MTrenk]

Notice that in the Ford Fusion picture, the rear deck element is raised up a significant amount in relation to the initial vertical placement of the trunk. If visibility is not a big deal in your car, then you could make your rear deck element about 3-5 inches above your trunk to get a much smaller transition area, which could greatly reduce that turbulent bubble behind your back window.

I wouldn't try vortex generators unless I had a degree in Mechanical/Aerospace engineering.

[Frank Lee]

Notice that in the Ford Fusion picture, the rear deck element is raised up a significant amount in relation to the initial vertical placement of the trunk. If visibility is not a big deal in your car, then you could make your rear deck element about 3-5 inches above your trunk to get a much smaller transition area, which could greatly reduce that turbulent bubble behind your back window.

No, it ain't.


Decklid extensions like that go out horizontally instead of up at an angle (Nascar) because they want low drag more than they want downforce. Going out horizontally instead of up to meet template reduces the rear wake area.

[MTrenk]

Hmmm. Pretty sure that the horizontal deck is in fact higher than where the top of the trunk is installed. Last time I went to the eye doctor I had 20/20 vision. Perhaps not as significantly as I mentioned earlier, but that's because the fusion has a much more tapered rear window than the Echo. It's up at least an inch.

The whole reason to put the deck up higher on the Echo is to take advantage of the curvature higher up on the profile.

Also, I'm pretty sure that we can see the difference between a rear deck lid and a Nascar spoiler lol.

[Frank Lee]

Maybe it's time for another eye doc appointment:


http://ecomodder.com/forum/showthrea...rag-598-2.html



Hmmm, pretty sure that is the stock trunk lid until back to where the extension is added on.

The whole reason NOT to put the deck up higher is to end up with a smaller wake area.

Mentioned NASCAR spoiler because it was mentioned.

[Beau]

http://image.hotrod.com/f/techarticl..._rear_wing.jpg

Here is a good, close, view.

Here is a site that builds them, with a variety of images.

http://www.edquay.com/spoilers/FBW1/index.html

[ChazInMT]

Sorry Frank, but there is some truth to what Max has to say, sometimes (Not Always) it is better to raise the entire height of the spoiler while staying flat to reach the "curve". Having a screwed up small wake can be worse than a big well-mannered wake. The Audi A2 is a good example of a fairly large well organized wake that has a very low Cd on a car.



I think Mauricio would be well served to raise his up a few inches to meet the curve sooner. Maybe a bit larger "Wake Area" but I think it will be easier to build and live with, and the wake area will still be "calmer" than currently.



If he really wanted to do this right, he'd make a Kamm.



Oh, and I agree with you, that hydrogen powered Salt Flats Ford Fusion Special has very little to no elevation added on.

[Frank Lee]

I was mainly talking about the case of the 999 which is close to if not spot-on horizontal from the stock trailing edge.

Certainly if an extension has to stick out several feet in order to meet template there could be liveability issues. I'd expect, though, that the lower you can make a deck extension that fixes the flow off the backlight, the better off you are because the trailing wake area under the extension will be smaller.

[Sven7]

I guess I don't see how a trunk extension of a couple feet is going to cause "livability" issues on a B Segment sedan. It's tiny. You can add over 20" overall length and still be shorter than a Camry.

[Frank Lee]

sometimes (Not Always) it is better to raise the entire height of the spoiler while staying flat to reach the "curve". Having a screwed up small wake can be worse than a big well-mannered wake.

why?

[ChazInMT]

Originally Posted by Sven7

I guess I don't see how a trunk extension of a couple feet is going to cause "livability" issues on a B Segment sedan. It's tiny. You can add over 20" overall length and still be shorter than a Camry.

I was thinking that it would be a pain to walk around, sticking out so far would require stronger engineering due to the leverage moment that is there. Invariably, the more it sticks out, the more it invites some miscreant to push or pull on it which would cause sudden and catastrophic damage.