Hitched Detachable Boat Tail finished. With tests!
 

Its almost done, should probably finish it this weekend. So I figured I'd show you guys.

http://photos-a.ak.fbcdn.net/hphotos..._2513714_n.jpg

Just laying out the framework here. I've attached it to a spare hitch bar I had. Yes, its an ugly method. But its solid.

http://photos-e.ak.fbcdn.net/hphotos..._1250561_n.jpg

Another view, its very hard to get a proper frame built thats still light enough to be picked up but still strong enough to support itself. This is as close as I could get it to the car in order for it to still serve its purpose.

http://photos-a.ak.fbcdn.net/hphotos..._3883716_n.jpg

Frame done and painted. Start of the wiring.

http://photos-f.ak.fbcdn.net/hphotos..._2222413_n.jpg

Wiring is done! Frame is done! The lights is just a trailer lighting kit. Plugs up into the trailer harness plug in the car.

http://photos-d.ak.fbcdn.net/hphotos..._3067989_n.jpg

Start of the skinning of it. Tin is fun to work with.

http://photos-b.ak.fbcdn.net/hphotos..._5119743_n.jpg

Skinning nearly complete here. Its got that airplane look going on.

http://photos-h.ak.fbcdn.net/hphotos..._5188707_n.jpg

As it stands now. Everything is done except for actually cutting the front pieces to fit the front of the car, forming some sort of gasket, and putting on the front glass. It should be done this weekend.

The only real probably is attaching it. I added a handle to the back of the car to grab (yellow/black cylinder) but it still weighs probably 50 lbs. Its really awkward to attach.

Right now I'm just going to use a floor jack until I get it finished and tested. :turtle:

Looking damn good if I do say so myself.

very nice !
Looking forward to seeing what results you get with it.

I think that if you don't want, a gasket shouldn't really be necessary... At high speed, the flow will see the transition as a bump, and it won't cause too much turbulence. Just make sure the leading edge of the tail is inset from the outer edge of the car by 1" or so, and you should be fine.

OTOH, why do it if you're not going to do it all the way?

Nice build !
we've all talked about this, now someone is DOING it.
Kudos to you and keep us updated !

Can't wait to hear how well it works!

With the gasket, I was more worried about the whole thing acting like a parachute with air trying to get in. I guess I can try it without it.

I only made the suggestion because I think that so little air will be able to get in with the lower pressure flow around the rim that there won't be enough "wind energy" if you will, to actually pull on it. Also, over time, a gasket rubbing will damage the painted surfaces on the back of your car.

If you don't feel it's going to be safe, by all means, use a gasket. We don't need the EM logo clearly displayed when/if the thing flies off and hits someone's car! :P (Assuming you'll put one on/in/around it, of course.)

In the other boat tail thread, someone suggested using bathroom shower surround. I realized I had some of this lieing around so in an effort to save time (and a buck) I went with it for the final pieces.

DONT DO IT!

It's horrible to work with. all it does is fracture and shatter. I should have stuck with tin. Its actually slowed me down as I'm now going to have to redo the pieces I did do with it. *Sigh*

But I do have some pictures from tonight. The rear is done. All the glass is on. I just need to finish shaping the front and I'm done. I am going to try it without a gasket. If I feel it could be improved I'll fabricate something then.

http://photos-a.ak.fbcdn.net/hphotos..._4375001_n.jpg

http://photos-d.ak.fbcdn.net/hphotos..._4239149_n.jpg

Also visible in the pictures: I chose to leave the corner lights exposed for this. I figured it'd be minimal loss overall, save the problem of forming a tight seal of the car, and I'd get to have extra indicators. Which wouldnt be a bad thing.

Sorry to go way off topic, i saw the last pic and thought "he put a sissy bar on a 600 R" :confused: . Oops thats the lawnmower :o .
This will be awesome when done. I cant wait for the figures. Watch that hanging flap on the right where it meets the bumper. (I'm sure you saw it already)

Re- bathtub acrylic - You have to heat the stuff up pretty warm before it becomes ultimately flexible, but once you do, you only have a few minutes before it remembers the new shape you've put it into. It's a PITA to work with unless you have access to a heat forming station.

Yeah I'm redoing the front pieces in tin as we speak. (: Its easier to cut and bends and holds its shape well.

It's done! I'll have day pictures and data in the next day or two.

Well I'm done. I formed a gasket out of some spare pipe insulation and will be putting it on the car and testing it out late tonight. YES that front top piece is coroplast, but it should be operational until I can find some more metal that will work there.

http://photos-h.ak.fbcdn.net/hphotos..._6388353_n.jpg

What's that tube for? The one between the tail lights.

the shorter one is a handle to control the thing as its put on the car. The longer yellow one is just the jack handle its sitting on. It's a 2 man job to put this on without a floor jack.

Well done. You have far more patience than i do. I can't wait to see the numbers.

ollie

Well I was going to do a run with it tonight, but I decided against it. It's rigid and solid, but not the mount. It bounces too much on bumps. I'm going to have to work out more than 1 connector. Possibly 2 stablizing type connectors.

Always something eh?

I can at least include a picture of how it looks on the car at the moment:

http://photos-c.ak.fbcdn.net/hphotos..._5919831_n.jpg

Now I need a way to mount it more securely to the car without doing anything TOO awful permanent. More tubes? (:

Can you fit a 3mm thick aluminum tab at the top of the hatch?

If you can, you might be able to make a couple aluminum bar clamps if you bent some straps into a L shape, and fasten them to the top of the frame. You'll also probaby want to put rubber or something inside them, so they don't damage the paint.

That way, you can slide the bottom into the hitch, and then if you can slightly deform the upper part of the frame by hand, you'll be able to clip the top into the hatch to keep it more stable.

What about some straps from a bike rack, they are made to hook over the top of the back hatch. They would be quick to attach and remove plus very simple.
Looks great!

I think that's really important, actually.

At night, the trailer lights being close together may send the wrong visual cues to drivers behind you: lights close together are what we're used to seeing on vehicles that are far away. You don't want to potentially contribute to that kind of mis-perception.

basjoos was struck from behind on the highway by a speeding car at night in his Aerocivic, and it's my opinion the close-together taillights may have been a factor. (See his thread - he's since added more conspicuous lighting to give the car more illuminated "width".)

I'll be incorporating conspicuous marker lights on my boat tail in the same position as your OEM lights for that reason.

Other than that... glad to see someone else forging ahead with this kind of project!

Christ: Could you do a picture? I was thinking of having a zip tie like device on the outside of the door. That way I could attach it one handed and it wouldnt go anywhere, but still disconnect it when need be.

why wouldn't you connect it to the roof rack?

______________________|

The | should be facing down, but you'll understand from that, I hope.

You fasten the _____________ to the structure or frame, so that when the thing is installed to the hitch, you can just slightly deform the frame enough to tuck the | into the gap between the hatch and the rest of the body.

Just like a normal L bracket, basically.

That could work, but I was wanting a pretty solid mount. As in no front to back, left to right, up to down, side to side motion at all. That would only do 2 of the requirements :/ I'm thinking a pipe in a pipe (basically how a hitch connects) with another 'hitch pin' to have a 3 pronged hitch, basically. Except have the other 2 somewhere else on the car.

Maybe on the bumper for that fast and furious look when the tail isnt on? </sarcasm>

You could also use those on the sides, to help with side/side mvmt, as long as the hatch seam is on the side of the vehicle.

Simple and (probably) effective. I hope. If not, well, you didn't really waste anything, since straps of aluminum are pretty cheap, and can be used for other things if you don't like the way it works out!

Nice work!

On mine I came off the steel bumper with a support frame (serves a similar purpose as your trailer hitch). But that alone is just a support for the weight. I clamped rods (with vinyl tubing over them) across the trunk lid to actually keep the thing in one place. It is strong, you can push on it and it solidly moves the whole car around.

I left my existing sidemarkers exposed, you can just see them directly from the rear. Also you can see the factory taillights through the window if you are up high enough.

One thing I did notice when I put that extension on the tail (which had the taillights closer together) is that a lot of people wouldn't get into their own lane when passing. I thought perhaps it was because my car might have appeared narrower. But then again, you're supposed to go fully into the other lane when passing, regardless of vehicle width. You don't crowd a motorcyclist out of his own lane just because he has a narrow vehicle.

I'm going to try to use the license plate screw holes later tonight to thread a rod through it and have a slip on cover on the center 2X4 frame board. It should work and it isnt under too much stress so I dont think it will be a problem.

The only thing I dont like about that is I'll have to put it on and off everytime I put the tail on. Originally my plan was to have a duplicate plate on the tail full time to avoid the hassle.

Ugly ugly ugly system that works amazing:

http://photos-c.ak.fbcdn.net/hphotos..._5619524_n.jpg

The metal simply wedges into the seam of the rear hatch.

I could almost stand on the very end of the tail and not worry about it and not worry about it. I'm going to have to do something about the hitch mount too. but for right now I want to get it road worthy and then I'll worry about cleaning the air on the bottom. (Less worried about it there since the back of my car isn't exactly smooth with the lack of underbelly panelling and hitch hanging off the frame already)

BUT! I do have a fairly smooth front and middle:

http://photos-c.ak.fbcdn.net/hphotos..._5278834_n.jpg

Screw those belly pans that are gonna get dented. Give me 1/4 inch thick 6061 aluminum.

Go offroad much?!

Hi,

I'm hoping to see both a coupla' pictures of this installed on the car (when you get a chance!), and it would be awesome to hear how it changes your MPG! Thanks in advance.

35 mpg average over several miles at 70 mph on a 10 mile run.

http://photos-a.ak.fbcdn.net/hphotos..._4365396_n.jpg

Thats way high for my car, and way high for my car currently (its been more like 25 with the cold and winter gas.)

It can't be helping that much. As you can see in the picture, theres a bit of a gap that I'm going to fill in soon. And the top piece is still coroplast.

I'll do A-B-A-B testing once I'm satisfied with the integrity of the whole thing.

Christ: Yes, actually. One of the vehicle requirements when trying to find a new car was that it could do work on my familys oak farm if needed. It's hauled down several trees and has never got hung up there.

Interesting.

Ive got a 2001 Legacy sedan with minor aero mods and Im getting about 31 mpg at 70 (scangauge).

With the Outback being worse for fuel economy in nearly every way, I guess this really shows that the rear is where the major drag is at.

However I do have a 5spd, I think your 4EAT actually has taller gearing. Do you know what rpms you're at @70? Im at 3200:(

Anyways well done.

At 70 I'm at 2850 rpm. So yeah, taller gearing with the torque converter locked.

Larger/Wider Tires though.

Obviously taller ride height.

And the wagon shape itself leaving that huge gap in the wake.

I'll be working on it a bit more after haloween. Along with the A B A B tests.

Also worth mentioning, I have overload coils in the rear. These are great to fix the problem of the back of the car sagging when I have it loaded down with oak, but in normal use actually gives the car a slight rake, I think this is also hurting mileage somewhat.

Awesome pic !!

The overload springs may help as they give a divergence angle to the under car area.
After I get the bellypan in the Vue done, I was going to test the theory.

I assume your vehicle is a Subaru AWD 4-cyl, correct? I'm interested in your design for my 4WD V6 Toyota Highlander. Can you publish the specs of the materials you used, angles, lengths, thickness, cost, total weight of the package, etc? This would be a BIG help! I assume if you go into a shopping mall parking lot you would have to take up 2 spaces. Also, you couldn't go into a hi-rise parking lot where you have to pull into a space against a concrete wall. On a street with meters you would take up 2 spaces. Can you see well enough through the glass (or is it plexiglass)? On my SUV I have a rearview wireless camera that is part of the license frame and only comes on when the car is in reverse. It transmits to a 2.5" color receiver on the dash and the camera has infra-red sensors for night time; it costs less than $125. Other than your design, I have considered a Kammback, or an extruded "bubble" such is seen on the rear of some semi-truck trailers. Great job! Buddy

http://photos-h.ak.fbcdn.net/hphotos..._7203351_n.jpg

Glass reinforced, top and sides matched up to the car. Now just the bottom and some paint...

Buddy: It's scrap for the most part, 2X4's, PVC pipe, and tin.

Cost is less than 100$, and weight is 50~75 lbs. Thats not a lot of weight, but its very awkward to maneuver something this big, especially when there is nothing to grab! I've had to add a handle to the rear plate and a block on the bottom of the hitch bar so the floor jack can have enough area to balance.

Eventually I might have to build a special attachment for the floor jack or something to remove this thing. It's quite awkward to get on and off.

Right now its

1) Back the car in
2) Take the plate off
3) Take the plug wire out
4) Plug it up
5) get the tail up in the air with the jack
6) Balance the tail and put a 1 1/4 pipe in a hole from 4 feet away.
7) Cuss
8) Try again, get it in, but be careful not to go in too much, as the hitch pin needs to also line up.
9) Put the hitch pin in and the cotter pin through it.
10) Check lights
11) Put plate on back

Looking forward to it!

Man I wish I had a garage!

Mine is hinged at the back. When I remove the trunk nuts, I can flip it back and it lays flat on the ground. An old blanket on the ground is nice. Then I can unbolt the support frame from the bumper.

With yours, I'm thinking you could have it on the car with a full tank of gas (most weight), then back into the garage. Build a wheeled cart out of 2x4s that supports the tail near the front and back. Pad the supports with an old blanket or something if you'd like. Then you can remove it, and install it later, with a lot less effort. And store it out of the way easier too.

If you are going to be using this over the long term, you could rig up a rope harness with a block and tackle to suspend it from overhead. Store it up near the ceiling when not in use, then lower it down to your hitch mounting height when you want to install it on your car. Be easier then trying to balance it on a jack and similar to the way that some people store their pickup truck camper tops when not in use.