Interesting Aerodynamic Cars (Mike Vetter's ETV, also Avion)

[kach22i]

Originally Posted by freebeard

I thought I'd get raked over the coals for posting a motorcycle in an Aerodynamic Cars thread.

Google search in the images section "tricycle car" to get many excellent results.

"3 wheel car" also works.

Found the below in a different manner.

http://forums.pelicanparts.com/off-t...ures-1460.html

[cosmick]

Originally Posted by freebeard

Citation needed.

Would that drivetrain be front-engined or mid-rear?

Mid-rear. I've been trying designs in SketchUp Make, it is free downloadable 3d modeling. The Locost forum has great info for what metal is adequate, likewise plans for DIY CJ5 Jeep frames. I've done adapter plates before, getting either engine to that transaxle is doable. But enough about mine.
My reference to triple drag is not an exact scientific ratio, but is really obvious if you compare even something like the '83 RX-7 I'm building against something more like this: http://img546.imageshack.us/img546/3451/1326657812.jpg

[cosmick]

Originally Posted by sgtlethargic

I'm with you. Not everyone needs a 4-seater or more. I know I don't. Cut the frontal area and weight.

I've been thinking it'd be safer for a side-impact (T-bone), too, if the occupants were centered, further away from the doors.

I like turbo propane, too. But, I don't want the tank in the trunk again. It's easier and more assuring to have it completely separated from the passenger compartment.

Any more info on your plan?

I'm thinking most of my side-impact protection will come from nimble crash-avoidance, and secondarily from the overkill frame design I'm leaning toward, which has 2" x 2" mild steel square tubing of 1/4-thick wall thickness, along the occupant shoulders, on past the fuel cell, which would be between the occupants and the engine. The overkill steel would also go around the occupant compartment in other ways / areas, especially in front of the feet and something tubular curved overhead to meet the plexi canopy, if I can find a plexi canopy. Anyway, gasoline or propane will determine the firewall between fuel and human. I considered fuel in the lower frame, but then decided that's better for coolant hoses, brake lines, and possibly p/s if it proves necessary. These might all be braided stainless.
Still working on the fore-aft relationship between the driver's feet, the front suspension, and the radiator.
The bodywork is likely to be fiberglass formed over a hand-shaped wooden buck shaped by myself.
I need 60+ MPG HWY, I need it to spike at least 75 MPG at least twice, and it needs to be fun to drive anywhere, anytime, for under $10,000.

[freebeard]

(VW, where's the One Liter car you promised ?)

I like the VW NILS, but it's a single-seater.

Originally Posted by kach22i

Google search in the images section "tricycle car" to get many excellent results.

But the B-ROCKET is a two-wheeler.

pelicanparts

That's the Old Crow Racing 'tanker. It has an engined turned aluminum greenhouse over the patina'd paint.

Originally Posted by cosmick

...if I can find a plexi canopy.

A sailplane canopy in Czech Republic


Aerocoupe

Mark Murphy's Electrathon racer kit.

[cosmick]

Aircraft canopy construction
led me to:
Todds Canopies - Home
Their iceboat canopy is about what I was thinking if single-seat.
In fact, the whole back half of that looks good to me.

[some_other_dave]

Originally Posted by Occasionally6

(VW, where's the One Liter car you promised ?)

It's available in Europe only, and costs approximately one boatload of money. (OK, a very small boat--but ~$150K is more money than most want to spend on a high-efficiency commuter car.)

-soD

[some_other_dave]

Originally Posted by cosmick

...my side-impact protection will come ... secondarily from the overkill frame design I'm leaning toward, which has 2" x 2" mild steel square tubing of 1/4-thick wall thickness, along the occupant shoulders ...

Strength is one part of impact protection. Another, possibly more important part, is distance. If the steel tubing is along the occupants' shoulders, it won't take a really huge hit to move it into contact with said shoulders. If you put the tubing one foot away from the shoulders (and from anywhere a part of a belted-in occupant could be) then it takes one whale of a hit to deform it enough to contact the occupant.

Another problem with super-overkill structures: They don't absorb energy, they pass it on. Race cars in the ~70s or 80s figured that lesson out--the frames and cages got stronger and stronger, and you wound up with people hurt inside of cars that suffered relatively little damage. Nowadays, the high-speed racers are designed to deform and/or shed parts, in order to absorb the energy of a collision.

I'm not trying to say you're wrong in your approach, but do remember that there are lots of things to consider when trying to design in safety.

-soD

[Frank Lee]

1/4" wall!!! Are you building a plow?

[aerohead]

Originally Posted by cosmick

Mid-rear. I've been trying designs in SketchUp Make, it is free downloadable 3d modeling. The Locost forum has great info for what metal is adequate, likewise plans for DIY CJ5 Jeep frames. I've done adapter plates before, getting either engine to that transaxle is doable. But enough about mine.
My reference to triple drag is not an exact scientific ratio, but is really obvious if you compare even something like the '83 RX-7 I'm building against something more like this: http://img546.imageshack.us/img546/3451/1326657812.jpg

The Formula 1 or Indycar would have in the neighborhood of Cd 0.54.
The Nissan Deltawing is Cd 0.35.
The wheels really need to be shielded.
Even the 1953 GM Firebird-I is no better than a 2014 Nissan Versa

Cd 0.311

[cosmick]

Originally Posted by Frank Lee

1/4" wall!!! Are you building a plow?

Not the entire thing, just the upper part around the occupant(s), about bumper height to stock F150s. Seems the most likely danger.