Full boat tail on a Matrix

[Weather Spotter]

Good tips

How Much $$$ did your tail cost?

[Weather Spotter]

Well I got a cost for a junk yard hatch $475.

I polity declined. ROI would be just too long.

Back to plan "B" using the trailer hitch

[Weather Spotter]

Here is what I have thought up so far:

from hitch back 48" horizontal.
from hitch height to height at back will rise 14"
Back piece will be 18" tall and 24" wide.
Width at bumper is 56"
height from hitch to top (about where the Kamm ends now) 43"
Total height 46"
From the hatch hinge to the back plate is 6" horizontal.

sides at bumper rise 28" vertical (it goes in 8" in two bumps but I will run up vertical)
then bend front and in (24" long piece) so that the width at top is 40"

I have a hand drawing that I will try to scan in.

[Weather Spotter]

Car currently:



Drawing 1:


Drawing 2:



Top half will need to be see through. How should I do this and get rounded edges? I want this piece to open as a hatch. The lower part will be stationary, attached to the hitch and the lower hinge on the top.

My frame will come close to touching the car but will not (except at mount points). I will close the gap with foam and fiberglass that is only attached to the frame not the car.

Ideas?
comments?
Is my slope right?
I was thinking of making the frame out of 1" square tubing, will this work or is there a better idea?

I hope to get a $$ figured out and I might start in on this as I have a long trip at the end of next week that I will need to drive fast to make it in one day so I will need all the aero help I can get!

[COcyclist]

This is similar to what I have in mind for my hatchback. I have welded up the support that plugs into the hitch but that is as far as I have gotten. I am going to leave the top lower than the top of the hatch glass to leave a space to see out of. It's not quite as clean aerodynamically but I should get some of the benefit, especially if the sides are at the correct angles and the top intersects with the template. The top could be hinged to allow normal function of the hatch.

[basjoos]

You can put bends into1/8" Lexan, especially with a little heat to relax it. You'll just have to build a stout under frame (attached to the hatch) to hold the Lexan in position. That's what I did on my boattail.

[Weather Spotter]

Well I got the boat tail bug that has been going around.... and started working on mine again.

This time I stopped drawing and got the 2x4s out and started building. It is not the best shape but it is what I can build and make cheaply.

My goal is to keep the costs under $200 for a boat tail that works and looks decent.

To keep costs down I am using 2x4s as I have a pile of extra ones in the wood shed rafters. I can also build things from wood better then I can weld

As always I am making it reversible (it will be a hassle but doable) and I still want some access to the back part of the car from the new tail.

Here is what I did yesterday:





Mock up:






More progress on the frame:

[Weather Spotter]

today I could not build more and still get it out of the basement so I took a slot in the garage and started further building:













Mount to the hitch:


with top brackets in place:









With additional braces on bottom (one bolts through the ball hole on the hitch):


I started on adding the foam to make the shell but I did not get any pictures. I plan on covering everything but the top from the back to where the top braces attach. This area I will cover with Lexan or plexi glass.

Ideas?

[KITT222]

Looks good! How stable is it? If you are still thinking about using a junk rear hatch for building on top of, I found a hatch in my area. If you could hold off until June on making a permanent hatch, I may be going to a Vibe meet in central Michigan at that time, and could bring it with. Or it could be FedEx'd. I could check the price on it if you're interested. Here's the link:
2007 TOYOTA MATRIX PARTS CAR

Regardless, you've got a good start there. Have you tried driving with what you've got on the car, just to check it out? How does the hatch open with that on?

[Weather Spotter]

Originally Posted by KITT222

Looks good! How stable is it? If you are still thinking about using a junk rear hatch for building on top of, I found a hatch in my area. If you could hold off until June on making a permanent hatch, I may be going to a Vibe meet in central Michigan at that time, and could bring it with. Or it could be FedEx'd. I could check the price on it if you're interested. Here's the link:
2007 TOYOTA MATRIX PARTS CAR

Regardless, you've got a good start there. Have you tried driving with what you've got on the car, just to check it out? How does the hatch open with that on?

I looked into a spare hatch to use, my local junk yard wanted $400 for it. Ouch! So I went with plan B, using the trailer hitch. At the moment the hatch does not open but I did take off the glass portion so that is open.

How much do they want for the hatch? Thanks in advance for asking. I just would cut it so I had the latch and the outer frame. Then I would weld a boat tail to that (would give me the exact shape and a mount point right next to the car).

After looking at it I think I will try taking off the whole hatch tomorrow after church. That will give me access to the top bracket bolts so I could take off the boat tail without having to remove any foam (which will be fiber glassed).It would also let me use the new interior space for cargo. I am planning on making the new lexan area hinged to replace the hatch function. I might even get creative and reuse the glass hatch shocks to move the new lexan hatch

I have not tried driving it yet, with just the frame it would just be a sail in the wind. But I did try pushing on it in most places. I can make the car rock side to side and up and down by putting my weight on the back end of the tail. The tail seems to move in unison with the car. It does not move at the hitch (which is bolted to the frame of the car) and does not wiggle at the top mount points. It moves a little near the bumper but that seems to be minor and should be fixed by the outer shell.

I think tomorrow I will have enough done for a test spin. I might not have the lexan on yet ($60 I have yet to buy).

Any ideas for the exhaust pipe area? (no pic yet, might get tomorrow) I need to make it turn down, or get creative in my hitch cross brace to under side of car pieces.

How hot can Dow Styrofoam withstand safely? Can it touch the exhaust? Should I cover it with albumin foil first?