what is the Cd of my trike?

[drmiller100]

Originally Posted by Cd

Actually guys, Skyking had the same idea but posted first.

"The idea of Cd's looks good, but in the real world doesn't really work out. When you look at it IRL, the sizes just don't work, and building that thing onto the door is beyond my skills. "

Are you serious ? All this would be is a raised section with a radiused edge near the hinge portion of the door.

I'm a huge fan of the Myers Briggs Personality Index, and it helps me understand myself, and others. FWIW, I am the classic, old school ENTP.

I am NOT visual. I have a tough time Imagining the LOOKS of things. I have a tough time making things LOOK good. I can't imagine how things will look SPECIFICALLY.

I'm good at understanding how things WORK, and how to improve how things WORK.

I thought the idea of a FWD reverse trike would be cool. So, I built a frame. put the engine in. suspension. Then I scabbed on a nose from an old mold I had laying out back.

Then I hired a guy to do a bunch of body work to make it all look a little better, then I ran out of money to pay him more. Now I'm going to work on making it drive.

Lets be real. I'm going to make it drive, grab some numbers off it, and then report back. I certainly hope I am better then .40 Cd.

I honestly believe .20 is realistic based on the current shape, and some clean up on the rear of the fenders.

I hate the rear scoops. I'm probably going to cut them off, smooth it over, and put a HUGE stripe on the side like the pic from Kach has.

Is there anyone else out there who has the desire to build something like this? I sure am curious no one seems very interested in building something like it.

It was pretty easy.

[skyking]

I think it is great, go out and drive the crap out of it, report back on handling too.
I won't build something like that for one reason only; the wife would not drive it. You know how women are. If it is in our stable I want it to serve both of us.

[drmiller100]

if i can get it together to sell them, the market opportunity is not the eco folks.

the real market is yuppie males in their 30's and 40's who drive or want to drive high performance motorcycles to work.

this would be a FUN 12 month commuter car.

[Sven7]

Cd, stop being a dick. You know why.

Miller, perhaps string two bungee cords from the rear end of the door to the outside edge of the fender, and secure some spandex or canvas over them. The door latch should keep it taut and it wouldn't be too too hard to try.

I've got a project like this brewing in my mind, but a RWD version of much lower hp It'll be interesting to watch how this one pans out.

Edit: regarding the "huge" stripe. I'm not sure it would work with the window graphics. With all due respect, the Corvette front end and the Civic doors don't really match. Using a bright, light color like yellow or orange could distract from this, and black is always a good "wow" color. Of course if you don't have a really smooth reflection on that rear quarter black would be a bad choice. In a lighter color it may look better, but not white. Just trying to help.

[NeilBlanchard]

The Corvette of that ilk had a Cd of 0.45, if I remember correctly. Interestingly, this is the same Cd as the VW Beetle (the new front wheel drive one, up until this year).

[kach22i]

Originally Posted by NeilBlanchard

The Corvette of that ilk had a Cd of 0.45....

That's odd, I would have thought the the sharp clean rear edges for air to let go of, would produce a lower number than a conventional Corvette.

Chevrolet officialy introduced the Corvette Stingray Concept | Automotor Blog


Were the air-curtain intakes up front perhaps fake and acting as air catchers?

[ecomodded]

Originally Posted by NeilBlanchard

The Corvette of that ilk had a Cd of 0.45, if I remember correctly. Interestingly, this is the same Cd as the VW Beetle (the new front wheel drive one, up until this year).

Actually the Cd is 0.38 in the old New Beetle
In defense of my cars weak but not quite that weak aerodynamics.

[NeilBlanchard]

The bulging fenders are NG and the flip spoiler at the back hurts it, too.



I stand corrected on the older "new" VW Beetle -- 0.38 it is.

[aerohead]

Originally Posted by drmiller100

Aero, Thanks for your comments.

A few things. The 4 dimensional model is interesting. Yes, I have some stagnation area behind the front wheels, and yes I'm curious to find out what cut outs do.

If you look at the windshield, it is actually well behind the front fenders. I expect high energy air to flow off the hood, spill around the cockpit, and add adequate energy for the back of the car.

I'm pretty confident of that.

i'm so confident I put the goofy air scoops on the back to make ti look cool, but now that the car is outside, I hate the goofy air scoops at the back, and they are getting changed or removed.

as for covering the wheels, am I better to cover the wheels and close behind the fenders, or am I better off to leave the wheel wells open, open behind the wheels, and let air flow in the wheel wells and out the huge openings behind the fenders - basically make the back of the "fender" look like a fender, but not at all functional?

In 2006,George Parker did a press release for his 'fuel vapor technologies 'ale'' 3-wheeler.I'm sure you could GOOGLE it.
I would recommend you treat the area behind the front fenders as Parker has done.
Where the air is separating here,is near the lowest for the trike,and all adjacent air is going to attempt to spill into these voids,creating tranverse flow,some of the worst there is.The flow will create the shearing forces which spin up eddies into full-blown turbulence.
Even though the nose,windshield and body are 'clean',the fenders are going to rip the air apart for the rest of the surfaces.I don't see the flow re-attaching .

[ecomodded]

Originally Posted by drmiller100

Note the back is "behind" the front - so I add the frontal area of the hood plus the frontal area of the "greenhouse" - windows and above.

Any guesses on Cd?

Aero?

under .20????? (I am hoping?????)

My guess was 0.19, half my cars cd.
You have probable thought this design out already but..
But my real point for posting was to give out a idea for the doors, even if not for this project, anyways, if you changed the hinges to open as suicide doors you could make the door panel to match the hood/fenders, if you wanted that is.
With a good design it may not require too much panel shaping possible just a few easy lines over a light frame.