Boattail camper for Prius V

[ai4kk]

I've got a 2013 Prius V that I've been making into a mini camper for my dogs and I. I'm a travel nurse so I tend to make long cross country drives with lots of local driving and exploring around an area while I'm assigned there.
Usually it's just me and my dogs in my Prius and there's enough room for me to stretch out next to their crate so we can all enjoy the AC or heat while we sleep, but my partner plans to be joining me soon and we've been figuring out ways to fit us and the dogs in like for our upcoming cross country trip from Florida to Washington.
For this trip we're just taking the tailveil hatchback tent and sleeping in that with the dogs in the car.
I was reading an article the other day about a guy with a Metro who put a boat tail on it and the author of the article made a comment wondering if somebody had added a bed onto their car and it hit me that maybe that's the answer...an aerodynamic boat tail that will pick up some miles per gallon on what is probably the worst aerodynamic part of the Prius v (the big square ass-end) and give me enough room to put a full size mattress in the boat tail and the dogs can have the car. I already have a 2-in receiver and cargo platform so that could be the structural start of the bed and then the rest could be built around it with foam and fiberglass, maybe even use the top part of the hatch and hinges to hinge the top part of the boattail like a clamshell.
Has anyone ever seen something like this done before? It just seems like a perfect solution both for enhanced mileage and more space. I've seen boattails done as hitch boxes to carry more stuff in but never as a camper

[freebeard]

Aerocivic.

https://ecomodder.com/forum/showthre...1-0-a-290.html

Cargo area inside boatail, extending the interior of the car into the boattail added 20cu ft to the interior space. Also there is a hidden compartment under the new load floor in the boattail.

https://ecomodder.com/forum/showthre...ing-39379.html

[ai4kk]

Yep, that's the idea! Heading to your thread next.

[cRiPpLe_rOoStEr]

Most likely my vehicles of choice for a camping setup would be something more suitable for stealth-camping, but I also have a motivation for a similar project. Much easier than looking out for a pet-friendly hotel

[aerohead]

The PRIUS-V already suffers an aerodynamic penalty, due to the lack of meaningful slope in it's roofline, compared to the PRIUS.
Cd 0.29 vs Cd 0.25, a 16% loss.
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If you yanked the rear hatch, and constructed a hollow tail section, extending the existing roofline down, plus adding to the plan-view body camber and baby boat-tailing, plus some 'slow' diffuser down below, you'd really have something, depending on it's final length.
And if you 'light-weighted' the construction, the added mass might not equal what was removed by deleting the OEM hatch.
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A remarkable amount of drag reduction occurs within these curvature 'origin' areas of streamlining.
I suspect that you'd easily 'beat' the regular PRIUS' lower Cd.
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I looked for 'Champrius' here at EcoModder but couldn't easily locate it. It's a 2009 PRIUS with extended tail 'camper' space inside, and pretty terrific mpg.
It's easy to find at GOOGLE.
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You can probably find a 'blueprint' for the V online. It would show, in 'true-length' all the actual geometry of the car, and an enlargement done at a local copy center would allow you to 'explore' the 'construction' on paper, to see what you think you could stomach.
LIGHTYEAR Zero is currently leading the pack on low drag. A careful study of it's aft-body, in different views would be invaluable to you.
The relationship between fastbacks, squarebacks, 'geometry', and drag are well understood ( notchbacks: forget it! ).
Your Prius is a squareback and will respond well to squareback 'known quantities.'
Contrary to some prevailing views, you'll essentially be at a 100% confidence level of attaining attached flow and drag reduction at any chosen body length.

[freebeard]

Guugle is evil. DDG:

https://ecomodder.com › forum › showthread.php › 66-mpg-2009-totoya-prius-champrius-4-0-a-40280.html
66 mpg 2009 Totoya Prius, Champrius 4.0 Under Construction now
7 Jun 2022Howdy all! I'm the creator and owner of Champrius, the Champion Camping Prius. (pronounced with stress like champion, not like Prius). My last revision of her (3.0) peaked at 66 mpg @ 65 mph unladen and got 61 mpg in real world use. In March 2022 I had a fender bender that destroyed the boat tail and decided to do a major upgrade.

Boat tails add crush depth.

[ai4kk]

Originally Posted by cRiPpLe_rOoStEr

Most likely my vehicles of choice for a camping setup would be something more suitable for stealth-camping, but I also have a motivation for a similar project. Much easier than looking out for a pet-friendly hotel

That is part of the reason I chose the Prius V in the first place...plenty of room for my large dog crate and it's easier to leave the AC running since my dogs go everywhere with me. I also made a sign for the rear window that there are dogs in the car, the car is climate-controlled even if the engine is off, the temperature is remotely-monitored via cellular and ham radio, and giving my number in case of emergency.
You can also do the same thing (run climate control without running the engine full time...it just starts every 10 minutes or so to recharge the hybrid battery then shuts down after 30 seconds. I also use it as backup power for my off-grid home) with bigger Toyota hybrids but I can't afford a new hybrid Sienna

[ai4kk]

I'll probably start on the boattail after I get out to Washington next month, will have my Subaru to drive while I work on the Prius since I left it out there last Fall when I came back to FL. In the meantime, putting my pizza pans er I mean wheel discs on this weekend. I may even find time to build some rear wheelskirts before the trip but not worried about the front wheelwells
The construction plan is to support a lightweight steel full-sized bedframe immediately behind the car and slightly lower than the bottom of the rear hatch opening (about 4" lower so the mattress is even with the floor) at 3 places....one support going to the 2" receiver and 1 on each side from the sides of the receiver to the two rear corners of the bedframe. This should give me a triangulated frame that should support two larger people while the car is at rest and not bumping down the road. If I decide to carry cargo back there while driving, I can always add ratchet straps from near the hatch hinges to the rear corners of the bed on either side to help support it in tension. There will be a steel hoop (I think angle-iron would be heavy enough for this, maybe even aluminum) at the rear of the bedframe like a footboard that will give a solid mounting surface for the upper half door latches, taillights etc as well as set the shape for the rear of the boattail and ensure room for my feet.
For skinning it, I'll probably use a lightweight PVC or Poor Man's Fiberglass (PMF)-encapsulated wooden frame covered with foam and PMF (or perhaps something even lighter since it won't be under a load) unless someone can convince me that real fiberglass has enough advantages to be worth the cost. of course adding the foam would make it better-insulated and cut back on my engine cycling if I'm using the climate control in standby mode. The bottom part will be mounted to the metal framework mentioned before and faired into the lower body and the top part will be mounted to the top half of the hatch after I cut the bottom half off and will use the factory hinges, weather-sealing, and hydraulic struts which I can upgrade if necessary...or perhaps even replace with actuators. I plan to build and fair the entire tail unit first before cutting the split so that the top and bottom half match and then working on sealing the gap when it closes. I may add rear and side windows later on but skipping them for now...I can always put extra cameras back there and if I add windows I'll also have to figure out how to cover them up when sleeping.
I'm thinking rather than trying to keep the original taillights exposed (which would add a lot of complexity and possibly some drag) just cover them up (leave them functioning in case the boattail ever comes off) and mount lights in the rear of the boattail. I also plan to keep a receiver open (use an extension and weld the bedframe support to that) so I can put a trailer hitch in although any trailer will have to be modified with a long tongue, but that will still probably give better mileage when hauling than putting things on the roof.
While PMF doesn't finish out really shiny, the car is currently matte black (cheap rattle-can paint-job covering the former yellow taxi paint which is itself over the original silver paint), I plan to eventually redo it in semi-matte John Deere Blitz Black so it doesn't have to take a fine finish.
Thoughts? Always open to new ideas.

[ai4kk]

I looked over the Champrius and while I'm sure I can learn ideas from him, he doesn't appear to be using the boattail as additional interior room or more importantly as sleeping space. The first reply to my post was actually the closest to what I had in mind than anything that I've seen anywhere yet.

[cRiPpLe_rOoStEr]

Originally Posted by ai4kk

I also use it as backup power for my off-grid home

Sounds nice. Whenever I move from my apartment to a house, going off the grid would be quite tempting...