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Old 10-23-2010, 08:27 PM   This thread is in the EcoModder Project Library | #1 (permalink)
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Full boat tail on a Matrix

I have a wish to see if I can design a good looking boat tail for my Matrix.

Wants:
look decent, aero civic or better. It would be nice to have it as good as 3-wheeler's but not a must.

Needs:
must still be able to see out behind the car.
Must still have full use of rear hatch.


Ideas:
use current mount points for Kammback (two spots on top, two spots where hatch glass shocks mount to glass).

The bottom mount would be the trailer hitch.

Mount it in a way that the whole thing swings on hatch, and hooks into trailer hitch when closed.











Comments, ideas?

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Old 10-24-2010, 07:27 AM   #2 (permalink)
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Looks like a good project. A couple of points to think about.

If you have it attached to back of the hatch and swinging up with the hatch vertically when you open it in the manner of the nose of the C-5 cargo jet, you will need to install stronger gas stuts to take the extra weight of the boattail. Also if you design the boattail so it can hold cargo (a useful idea), it complicates the gas strut situation since, unless you plan to unload the cargo each time before opening the hatch, you will have a wide range of weights that the struts will have to lift and the cargo could get tumbled as the boattail pivots skyward.

An alternative design is to design the boattail so it pivots horizontally rather than vertically to open out of the way of the hatch. This eliminates the need to beef up your struts and the problem of varying cargo weights. There are some spare tire holders for SUVs that are designed to pivot the spare tire out of the way so you can open their hatch that you might be able to adapt or copy to hold a horizontallly swinging boattail.
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Old 10-24-2010, 07:48 AM   #3 (permalink)
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How much length would you need to add to achieve your aero goals?
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Old 10-24-2010, 08:29 AM   #4 (permalink)
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Here we sort of figured that out when looking at the Kammback:

Help me design my partial Kammback

I think that I need to make the green line:

http://i33.tinypic.com/71mz68.jpg

Once I chop it off for tail lights and stuff I think I am looking at 4-5 feet.

The swinging sideways is a cool idea. How would I mount it? Off the trailer hitch?

Thanks for the ideas
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Old 10-24-2010, 10:32 AM   #5 (permalink)
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It looks like the ideal length from the top of the hatch to the tip is about the same as your wheelbase, which googles out at about 7.5 feet. Its not very practical to make one that long, that would make your total vehicle length about 20 feet long, the same length as many parking spaces.

If you look at a top view of your car, and use the same curve as the top line in your pic, how far out does that come to a point?
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Old 10-24-2010, 11:37 AM   #6 (permalink)
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When I calculated it would take 6-7 feet to come to a point. I would chop it off sooner to allow for lights and plate. So 5-6 feet is what I was thinking. Am right?
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Old 10-24-2010, 11:52 AM   #7 (permalink)
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Quote:
Originally Posted by Weather Spotter View Post
....Must still have full use of rear hatch...
Hi,

If you mean full use of the stock hatch, I would advise against it...

Creating an opening in the extension for the stock hatch will not be practical and severely limit the strength of the extension.

Mike from aerocivic already has the best idea regarding this. Copy his idea of creating a new hatch including any glass to see out the rear of your Matrix.

Then, with the stock Matrix hatch off the car, you can use the existing hinges as mounts for the extension. You will likely want to move your new hatch pivot points at least six inches rearward of the existing pivots to allow for mechanical strength of the extension in this area.

Just an idea on how to do it.

EDIT @9:59am

Just read Mike's (aerocivic's) response above, and opening the hatch sideways should work great for your Matrix, which has more height than the Insight. If you do go this route, try to keep the opening shorter than the full height of your vehicle to allow extra strength of the extension.

It's especially important to allow the top and bottom surfaces to start curving up/down before creating the side opening. This adds a lot of mechanical strength to the design.

Jim.

Last edited by 3-Wheeler; 10-24-2010 at 12:02 PM..
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Old 10-24-2010, 08:03 PM   #8 (permalink)
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Great ideas guys keep it up!

I had not thought of taking off the old hatch- but that would give me a lot more room to design it how I want.

I think Mike was saying to pivot the whole tail sideways - like some suv's do for the spare tire.

I might look into both ideas. I am not sure where I would mount a side pivot but I will look.


If I just replace the hatch with a boat tail I could have it pivot up just like the hatch.



Any more great ideas (others will be taken to)
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Old 10-24-2010, 08:45 PM   #9 (permalink)
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Quote:
Originally Posted by Weather Spotter View Post
Any more great ideas (others will be taken to)
Well, in that case, I'll ask what you think about the Prius.
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Old 10-24-2010, 09:21 PM   #10 (permalink)
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Quote:
Originally Posted by RobertSmalls View Post
Well, in that case, I'll ask what you think about the Prius.
I think that they make a good step in the right direction for most people who want to turn the key and go. I do not think the extra cost is offset by the small% better MPG.

I am not sure that the MFG methods is any better then a normal car, it might be worse for the environment.

Now the Leaf..... Might be a nice car. I want $$$ data first.

For now I will stick with what I have and get the best MPG I can. So bring on the mods

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