Aero Help On A Body Design

[Hasbro]

I'm looking for some aero input on a car I am working on. It's basically a mid engined Locost spaceframe tube chassis on which will be a full body with canopy. It sort of looks like a GT/Supercar but is very small. More a DD and Track Days car than a full track car. It will be a compromise but More aero efficient than downforce, which is why it's more bulbous than a typical GT car. Downforce can be, if necessary, enhanced with a wing etc. Full undertray. Body will utilize almost only simple curves. Very flat panels. Down the road a computer wind tunnel would be nice. Right now I'm concerned with function over asthetics. Looks will come later. Yes, it's very small but have had 3 street legal cars smaller!

Specs:
96" wb
11'.1" approx. length
62" track approx.
42-44" height
72-74" width
1,500 lbs.
Honda K24 "Frank", mid-engine layout
180+ whp, 160+ torque
55 mpg
No doors. Window canopies only
Windshield will be from copies of a Stratos, Porsche 917, or a Lola T-70, whichever works best. They are all DOT approved.

I'm terrible with computers so keep that in mind. These are very basic renderings to be used as work sheets. The front air dam will be more conservative to make use of the undertray. I would like the curve of the center hood area between the wheel pods to match the pods but there might be a driver vision problem. The front radiator vent can be removed and wheel well could be used. Other vents are not shown yet ;





Is the angle of the rear canopy taper measured from the very top of the curve?



Edit: front wheel pods will also taper towards the front but will be more blunt than this:

[Frank Lee]

Aww, named after me?!?

Go longtail; the rise is too abrupt after the rear wheels. Look to the GM Aerotech cars for inspiration.

[jerryd]

Depending on what you are going for, better mods would be less intersection angles to reduce intersection drag and better wheel well design like rear wheel skirts and front ones like the old Honda Insight and EV-1 did.

Your undeside rear needs more work, less angle and sharper cut off.

Nice look though for a Lowcost7

Jerry Dycus

[rkcarguy]

I'm playing with designing a similar setup via autocad. With the mid engine design there is enough room to take the area between the rear wheels and ramp it up to the tail at a more shallow angle than off of the rear tires. The angle can then be blended into the sharper angle off of the rear wheels if you don't want to lengthen the rear end.
May want to consider a widebody bugeye sprite fiberglass kit to begin with, the shape is close to what you want with the bugeye's(headlights) and tail chopped.

[NachtRitter]

looks interesting... subscribed

[vinny1989]

Looks good.

May i ask - what program are you using to create those drawings?

[botsapper]

Your target specs sounds interesting. I'm try to get a sense of the design project. Same hp. range, ht., & width of an Elise. Longer wheelbase but shorter length!, than an Elise. With the compound curve windshield (based -Stratos, 917, T-70, etc.) glass, I picture a 7/8's scale of a Riley Daytona Prototype with flatter slab sides. Your design has bobtail (short rear overhang) proportion gives it a great shorter track-car look but a longer overhang will give you better controlled trailing flow. The trailing rear tire eddies will be minimized & your lower belly air channeled cleaner.

[Hasbro]

Originally Posted by Frank Lee

Aww, named after me?!? Go longtail; the rise is too abrupt after the rear wheels. Look to the GM Aerotech cars for inspiration.

Yes, Frank, named after you. Short for Frankenstein, it's a motor comprised of the Honda K series 2.4 and 2.0.
I didn't want to go to a long tail for aesthetic and size reasons but I'm really starting to like it. It's still only 11.6' so would be fine on the road. Has a pretty cool retro look. What do you think?

Originally Posted by jerryd

Depending on what you are going for, better mods would be less intersection angles to reduce intersection drag and better wheel well design like rear wheel skirts and front ones like the old Honda Insight and EV-1 did.
Your undeside rear needs more work, less angle and sharper cut off.
Nice look though for a Lowcost7
Jerry Dycus

Ok. I'm looking for an extruded aluminum edge that the flat aluminum sheets can connect (rivets and Dzus fasteners) to, which would avoid complex sheet bending and soften the edges. I would like to open the body behind the front wheel but with large grills to maintain the body shape if that makes sense. The rear wheel skirts might be too much for me but will think about it. The wells are very close to the tires, however. The rear underside will have a diffuser so the area behind the rear tires might be angled for appearance - although I'm digging the "Frank Lee Longtail".

[Hasbro]

Originally Posted by rkcarguy

I'm playing with designing a similar setup via autocad. With the mid engine design there is enough room to take the area between the rear wheels and ramp it up to the tail at a more shallow angle than off of the rear tires. The angle can then be blended into the sharper angle off of the rear wheels if you don't want to lengthen the rear end.
May want to consider a widebody bugeye sprite fiberglass kit to begin with, the shape is close to what you want with the bugeye's(headlights) and tail chopped.

Would love to see your work. Are you a LocostUSA member?
Yes, there will be a tray underneath. I need to find an article that showed a new undertray with a circular modification in the center that helped top end speeds quite a bit (smoother flow), looked very simple. Anyone seen that article?
Which Bugeye kit are you referring to? There was a factory works fast track body or are you referring to a bugeye racing body? Pics?

Originally Posted by vinny1989

Looks good.
May i ask - what program are you using to create those drawings?

Paint. Yes, rough.

[Frank Lee]

What do you think?

Longer yet.