Build an efficient SUV from scratch

[wilcorp70]

So I have stalked these forums as well as the diyelectric car forums for a while now, and have really wanted to build a car from the ground up to be exactly what I want it to be. Its my final year of school (aerospace engineering) and I thought I would take advantage of the access I have to modeling software and engineering expertise while I have it. That said, I think the people here are the best at knowing how to make a vehicle. My plan is to make an SUV that is as efficient as possible while still meeting all the requirements from my wife.

The requirements are:
Must seat at least 5, though 6 is preferred.
Cannot be a van or a station wagon, SUV is preferred.
Must have heat, air, radio, etc. (all standard amenities)
Must have rear view mirrors (My wife hates the idea of using lcds)
If electric must go at least 60 miles and have possibility of range extending.
Maximum speed of at least 70 mph (I think 65 would be ok)

I think that is all of them. The plan is to have as much as possible diagrammed and parts preselected (within reason) so that it can be done as quickly as possible when construction begins. I know that there will be problems but hopefully using solidworks in the design phase will minimize these. I am going to use the GM skateboard concept of using a spaceframe with all of the drive components with a body bolted on top. The GM Hy-Wire is my inspiration here.

For the body, I am going to use a fiberglass over foam construction. While making molds would produce a lighter body, I like the added strength provided by the foam as well as the insulation it can provide to the interior which will hopefully reduce the need to use heat/AC. This method should also reduce fabrication time and cost.
My current rough mock up is based on an Acura RDX concept car. The actual car they made from it was hideous:
http://www.autointell.com/asian_comp...05-300-212.jpg
But the original drawings were brilliant, two views I modified to be a little more aerodynamic are attached. They were modified in paint so quality isn't perfect, but its my starting point before I start modeling. I still have to remove some trim from them add mirrors and such.
Any suggestions would be appreciated, especially for the body design. I can't do anything too extreme (full kamback) because of the wife acceptance factor. I'll put some more information in my next post, but this one is getting a little long.

[Frank Lee]

My suggestion would be to wear the pants now or it will only get worse.

[wilcorp70]

Haha, here is the thing, I hate for my projects to just be mine I wouldn't have married her if I wanted to do too much stuff without her. That being said, she would let me build a sports car if I wanted, but then I wouldn't be in this forum would I.

[Frank Lee]

You'd be here if you wanted to build an economical sports car.

[Ryland]

You said you don't want it to be a station wagon, or mini van but instead want it to be an SUV??? how do you tell those vehicles apart? to me they are all more or less the same thing these days, sure they started out as separate vehicles but now they are more or less the same.
But to fit your requirements, check out the Future Truck Competition, I met some folks who had vehicles in it a almost ten years back and they were getting 55mpg out of a vehicle that could seat 6 or 7 and tow a boat.
Of course there are those of us who realize that our compact cars can seat 4 adults or 2 adults in the front and 3 kids in the back and tow a small boat or other trailer while getting 40mpg or better and that for that once a year that you need an even larger vehicle you rent or borrow it.

[wilcorp70]

I definitely get your point with the classification thing, I remember reading about problems they were having at a recent car show because the show wanted everything categorized but the designers couldn't agree on what their cars were ie SUV, CUV, van, etc. For me its just a feel you get, so its pretty arbitrary. This design would probably be considered more of a CUV (my goal weight is south of 2000 lbs), but I can't bring myself to say that acronym out loud to people, so SUV works.
I think a lot of inspiration for this project came from the Revolution Hypercar SUV and how efficient their design was.
This project is very similar to the CarBEN project posted on this forum, but more budget minded. I have access to a real wind tunnel and lots of common sense shop guys who can help me figure out what steering and suspension to use.
I've heard a little bit about the future truck competition when I was involved with the EcoCar team here at NCSTATE, but I'll have to dig up some more info.

[wilcorp70]

Ok, so I added wheel fairings and flat wheels to the sketch I'm wondering if the slope on the rear of the roof isn't enough. Im working on a proper profile sketch that will hopefully make it more obvious.

[d0sitmatr]

why not use the revo as your baseline ?
it seems to have many characteristics from the start that a lot of us look for, and has a good aero shape right now, just needing a few tweaks.
Id start with that shape, extend the rear into a 1/2 kambak/1/2 boat tail. incorporate a full belly pan from front to back. a nice, smooth front end and wheel skirts for the rear and partials for the front (maybe ?)

your rendered CUV sits quite a bit higher than Id recommend, granted, its a concept, but personally I would drop it at least half of where it sits now. unfortunately, you risk it looking more like a crossover than a full SUV/CUV.

[wilcorp70]

Definitely considered using a donor chasis, but there are too many compromises there, I will use a donor car for things like fittings, suspension and glass, but I want a spaceframe chassis as a blank canvas. My dad built custom fiberglass cars for years; I'd like to think I can pull off just one.
As for the ride height, I need to make the wheels smaller and I'm seriously considering an airbag suspension to lower it when at highway speeds. How does the Aptera manage sitting so high?

EDIT: For some reason I thought you were talking about a Honda Revo when I wrote this, then I realized you were talking about the Revolution I posted. To be honest, my wife didn't really like the design, and I want this to be a family car. But you are right, it definitely has a lot of the characteristics we look for. It's CD is the same as the first gen Insight. It even already has a full body pan!!! I think they avoided skirts because they were trying to get mainstream car manufacturers to accept it. There are a lot of good ideas in their industry report about making cars more efficient: http://www.scribd.com/doc/38774531/Hypercar-Report

[d0sitmatr]

thanks for the link, it looks like a good read

sorry bout the confusion, I didnt even think of the honda revo.
Im surprised your wife doesnt like it that much, and I can understand the desire to create something from scratch.
the airbag susp sounds like a good idea, I believe the range rover had/has this as an option or as standard (not really sure) but I dont know if its adjustable. it does sound like your on the right track. if you could match, or even better the CD of the revolution that would be outstanding !