3rd gen Prius aeromod thread

[Vman455]

Good company to be in, for sure!

A sliding mechanism was something I considered, as well as purchasing a swing-away Stowaway frame instead of the fixed version. But, the former would have issues with sturdiness and present the problem of how to adequately lock it in place, and the latter would have necessitated an even larger gap between the tail and body because of where the hinge is positioned.

I cut the front bulkhead yesterday, with a cutout so I can still see out of the lower window for ease of parking. I'll extend that cutout straight back until it hits the slope of the side spars, and then continue at that angle. The top sides will be inset so the brake lights are still visible (and I'll put brake lights on the tail too), a la MetroMPG's Insight/Civic/Prius tail.

I'm trying to decide now what type and weight of cloth to use to skin this thing. Robert Riley's Tri-Magnum tutorial suggests two layers of 6oz fiberglass cloth inside and out, but US Composites has a nice 8.5oz twill that might work, or maybe over another lighter cloth. Thinking about some carbon/Kevlar tape to reinforce all the corners too.

[Vman455]

First mock-up:







This thing is going to be cavernous inside:



I may change the profile shape; right now, it isn't very aggressive, terminating at a 19-degree angle. The problem is the spoiler is almost parallel to the ground, and I don't want to risk detachment by going too aggressive too quickly.

[COcyclist]

Nice Vmann. I hadn't thought of making a rigid box of fiberglass over thick structural foam. I will be watching with interest. I have the receiver hitch but haven't been able to work out the details of doing this on my Golf.

[BamZipPow]

You might want to consider a secondary attachment point...even three attachment points. I have found with my single wheel trailer project that the large body will have a tendency to torque roll on the single attachment point given the extra leverage from the wider body just from the airflow around the body or the extra mass of the body.

[Vman455]

The box frame is now screwed and glued:





I changed the profile taper slightly, to match the plan taper:



Hatch opening clearance:



The carrier platform is pretty stout, and the box will be bolted to it at four points 14" square. But, if it torques at all it should be pretty easy to add some bracing to the bumper cover or license plate attachment holes.

[gone-ot]

Are there ANY shipping carrier-bolt holes back there (for tying down the vehicle during shipboard transit) that you might be able to make use of?

[hayden55]

Why not have a piece on the front edge to fill the gap that folds over and to on top of the hatch? Like a hinged piece? Im sure that would be an easy way to gain an extra couple percent if you're up for it. ��

[Stubby79]

I like where this is going...

[freebeard]

The leading 4" of the flap could be magnetic stick-on car door sign material. It's a flexible magnetic sheet.

I hadn't mentioned it because the box will be fiberglass, but if it hinges on that and adheres to the Prius that could work.

Shape-wise, the only problem I see is that the rear bulkhead is rectangular. Ideally, it would be half circular (pace Morelli and aerohead). At the least it should have as much tumblehome as the Prius. More is better.

[Vman455]

I'll be sanding and shaping the whole tail once I get the foam built up, so it will have significant tumblehome and the baseplate won't be square. Not quite circular, either, but more like MetroMPG's Civic/Prius tail, which showed good attachment on his tuft test videos.

A block-off plate for the top is something I'm still trying to figure out. Toyota, in its infinite wisdom, put the only release button for the hatch on the outside of the car, under the emblem, so I have to be able to reach that in order to open it. The spoiler is plastic, so magnets won't work for a panel hinged to the tail. Maybe something attached to the spoiler with a small opening to reach through and hit the button.