Efficient 4WD Jeep

[brucepick]

If you can have an aerodynamic shape, reduced weight, and reduced displacement and rpms, you should be able to produce really impressive mpg in a 4WD beast. IMHO (in my humble opnion).

So far in this thread, I think the only fixed requirements are 4WD and hopefully 40 mpg or better. If the other project definers are still open then weight, aerodynamics and power train specifics will determine the mpg. The 4WD drivetrain will reduce mpg from what it would be if that weren't needed - but it's NOT a show stopper.

Nearly all 4WD's on the new/used market are relatively boxy and not lightweight. Those that aren't, tend to be built for "performance" (Subaru WRX and Audi Quattro/S4).

People + cargo capacity, shape, and other requirements may still be open - but SOURKRAUT may have some requirements in mind there.

Subaru could make such a car but they don't seem to be interested. Their stuff is all either heavy, or go-fast, if not both. And their bodies are not built for low drag.

[SOURKRAUT]

I'm leaning towards the sand rail, space isn't an issue, all I need is a two seater with enough cargo area space for a couple duffel bags for weekend drill (proud weekend warrior, upcoming vaction to Afghanistan will fund this project). Check out the 2nd post in the link below.

First EV - Sandrail, low range low speed, for now... - DIY Electric Car Forums

Something similar to this but with a full body would be perfect, I could go for a rear engine and use reverse cut gears in the axles, shifter would be trickier though.

[SOURKRAUT]

On a side note, all of the people on this forum are great. I'm used to off road forums where the users can be rather... Unpleasant

[brucepick]

I can see why you would want one.

Link with 2nd post mentioned above, has this pic below.
It's a UVA Fugitive, a sand rail kit car made by a now defunct company. Main Page - UVA Fugitive Kit Car UK Owners Club

(I'm reading between the lines that your project needs to be highway-capable, right?)

[SOURKRAUT]

Yes sir. A similar frame to that with a lower top, slightly more aerodynamic shape, modified to run a regular 4WD drivetrain but backwards for rear engine mount + a TDI.

I think I could build the frame around the drivetrain then strip everything and stretch fleece over the frame then fiberglass over it. I could use foam pipe insulation when molding the body to keep a little space to make it removeable then build some body mounts when the body shell is complete. I could use coroplast for the belly pan and have a cutout for the transfer case to protrude out of (the transfer case I'm using angles down and to the right (left in rear engine).

[SOURKRAUT]

The only exposed parts would be the suspension components.

[brucepick]

The UVA is pretty narrow. A belly pan of about that width probably wouldn't need any bracing/framing to keep it from sagging. I have no welding/fiberglassing skills so you're way ahead of me in those areas.

[brucepick]

Now that you're thinking about an aerodynamic design for your vehicle, I think it's important to reference two key articles.

Our member basjoos modified his 5th generation Civic to a very slippery shape indeed, and was one of the first - if not THE first - to do so. Have a look at his thread: http://ecomodder.com/forum/showthrea...ight=aerocivic. Of course your project is pretty much a ground-up effort, vs. basjoos' modded car, but I think it's well worth a look.

Our very own aerohead, aka Phil Knox, has provided a template which can be scaled to guide the design of a low drag vehicle. Have a look here: http://ecomodder.com/forum/showthrea...rt-c-9287.html

That's the "Part C" thread, which has the template. You can find parts A-B-C-D-E by searching on these combined criteria:
- In the "Aerodynamics" forum
- "Aerodynamic Streamlining Template" in the thread's TITLE
- Posts by "aerohead"

You have a huge amount of work ahead, on any version of this project - good luck with it!

[ShadeTreeMech]

I like the idea of the diesel swap. There's good science behind that.

The hydrogen generator belongs in the unicorn corral.

[SOURKRAUT]

Yeah, I had heard about the hydro generator at NAPA and was all excited then after some real research I was gravely dissapointed.

My version will be a little bit wider and a little bit lower than the one in the picture.