Hitched Detachable Boat Tail finished. With tests!

[NeilBlanchard]

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.

[brucey]

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



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.

[majestic]

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.

[brucey]

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.

[JasonG]

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.

[Buddy]

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

[brucey]

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

[MetroMPG]

Originally Posted by brucey

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

Looking forward to it!

[wagonman76]

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.

[basjoos]

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.