Thanks guys, I appreciate it. I have a tendency to go "Nahh, I already thought of that," and ask follow-up questions that are so tightly focused as to border on the argumentative, but it's part of the process and I value your comments. So when I ask, for example "Does that make sense?" it's because I want to know, it's not a rhetorical question.
From Christ:
> Is that thing a Go-Kart?
That's 'cause I modeled it with a high end modeler (Rhino 4.0) and rendered it with a low end renderer (Rhino 4.0). Seriously, if I wanted to spend four days on detail work, give it a scaled background (a showroom with other cars in it, or the pits at Talladega) and render it with Flamingo it could look like a real car. Everything rendered with the 'stock' Rhino renderer comes out looking either like a fake whatever-it-is, or a real a bathtub toy. But for data to drive a CNC machine, Rhino can't be beat.
> It doesn't look road legal at all...
Everything that shows meets the Federal equipment specs. There were some design compromises for light height.
> With all sincerity, I just can't imagine keeping attached flow over that rear slope, and those sharp corners appear like nightmares to a 10 year old.
About 1930 somebody verified that large radii aren't necessary to keep airflow attached. Previous to that, every car-of-the-future had a bulbous nose and front edge radii approaching half the width of the car, but it turned out to be a waste of space forward of the front axle. From nose to front wheel the edges are well rounder than Hucho's non-dimensional radius of r/b = .045 (page 41 Aerodynamics of Road vehicles, which I reference a lot in this forum since most folks here are familiar with it and have confidence in it).
However, the radius of edges parallel to airflow (I hope! Though all I'm sure of is they're parallel to the direction of travel) are r/b = .18, roughly a third what they should be if they were perpendicular. My assumption is, since air going over those edges so obliquely (if at all) the "effective radius" is very high. Does that make sense?
But looking over my model again, there's one way those sharp corners would be a nightmare to a 10 year old--if I hit him in the shins in the school crosswalk.
From Bicycle Bob:
> I'd definitely narrow the front end, so that air would not be spilling from the front to the side...
I think you're right. Models and tufts, that's what I need. There are conflicts there between aero (I think the body should be the width of the tires before it gets to the front of the tires, to reduce the tire's drag and separation behind the tire, But for gentlest slope over the nose for a given body length, the body height shouldn't be the height of the tires until it gets to the middle of the tires) and styling (how round can it be and still claim to be an updated/inspired by/version of the Type 32?) and cost (the more slab sided the cheaper, which was probably what drove Bugatti--his later tanks were more organic) but from reading these comments I'll redraw it with a narrower and less pointy front end. Ain't CAD wonderful?
> ...and get the front and rear stagnation points closer to level.
Huh? I'm not following you. Level side-to-side? Level front-to-rear? Should F and R stagnation points be the same height?
> There's not enough air feeding to the bottom of the tail to maintain attached flow at that angle.
Any shallower and the tail lights get too low for the law. Besides, Hucho says four degrees so that's what I did. It will have a full bellypan which should help a bit. I don't think it's that bad; maybe it's an optical illusion, caused by the sides tapering in 15 degrees.
> The cockpit area looks ripe to perform mischeif, too.
As a roadster it'll have a tonneau and a fairing behind the driver's head (with a roll bar inside). It's a pity the road rules prohibit Lexan canopies...I'll have to look at how that single seat Metro was done (second post on this thread--MetroMPG, do you have a link to that?).
As a coupe, well, I'll have questions for y'all in the Spring. My concept isn't fully developed yet.
> A classic small flat racing screen would leave a big wake.
True indeed, and I doubt I'll use one. I know in some states a windshield is required, not in Oregon though so I may just dress like a biker for weather and eye protection.
Here's another view of the same draft as the blue on, just not rendered, from more to the side. The tail doesn't look so extreme when viewed from the side. Any other angles anybody'd like to see?
PS--samandw wrote:
> I wonder if the aft treatment on the Fiat Turbina would be something to look at.
To look at, and indeed to drool over. Gorgeous and efficient. But probably 20 times as expensive as my budget ($2k for the body) allows.