Baby template car for DARKO 2016

[aerohead]

Originally Posted by freebeard

I've made some progress keeping the rain off; I just put up a 4x10ft skylight. Now I just need to heal it into the corrugated metal. Then I can think about kitchen cabinets or making an 8ft teardrop.

How much longer until you feel you'll be ready to reschedule Darko?

BTW, did you know? Just A Car Guy: the world’s largest salt flat is in southwest Bolivia, near the crest of the Andes

I'm afraid to even guess.I have a track record of being the world's worst estimator
I can't guarantee that the truck will survive for any length of time.And I could be killed or die any day.I'd really like to test the full suite of modifications if I'm gonna go,and really get the biggest bang for the buck at DARKO.
There's nothing hard about the build,but it's extremely complicated,since most major components must be able to break down and then reassemble for testing ( in order to all fit in the truck).

[aerohead]

Originally Posted by Xist

Are you going to fill in the hole you cut around the hood extractor?

Yes,not only for aerodynamics,but also to restore 'beaming' strength to the blister,lost when I made the cuts.

[aerohead]

Originally Posted by COcyclist

Phil, will the pontoons be removable for testing? That could provide some interesting data.

Originally,that was in the plan.Do to the difficulty of attaching 'Baby' to a ground board,I don't think I can absorb the cost to remove them.There's 8-pieces involved,which would have to be dealt with,then remount to the ground board (which would probably require removal and reattachment to the through-the-floor load cell uprights).
Also,all the fairings require fillets at their attachment points,which would take a ton of time to fabricate,while if stationary,can just be created with caulk.
Perhaps in the future,this is something I could deal with.
In the meantime,we know that these fairings can reduce wheel drag at up to 80% according to MIT's Goro Tamai.If I get below Cd 0.15-.13,the fairings will have to be responsible for the difference.
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I am going to try and do removable fairings on 'Spirit.' Access panels in the rocker panels would allow fairly easy attachment/removal.

[aerohead]

Originally Posted by gumby79

^^^
As well as just spats in front of the tires ,to determine how much of an impact the full boathauling the tires is.

I'm going to stay away from spats.I feel like they would need to be optimized for each vehicle,and only after great expense in the wind tunnel.I simply can't afford them.
The fairing package I'll have a high confidence in.They're the 'ideal' way to go,so
I'll stick with them.

[aerohead]

Originally Posted by NeilBlanchard

Phil, my only surprise is the "recurve" at the end of the tail:

Yes,me too.I wasn't going to do it originally,then I got to thinking that this was potentially a road-going shape,of which the constabulary would expect taillights and a license plate.I needed to create the facility for the width and height they would require.
MIT did this trick with one of their Morelli-shaped solar racers and it still scored pretty good drag numbers.
It's just a concession to 'reality.'

[aerohead]

Originally Posted by Magajgfha

Why don't rear pontoons cover wheel sides?
Wouldn't it be beneficial to move the front wheels backward to make the front of the pontoon smoother and to push the air disturbance further back?

*The leading edge at the front wheels is a concession to the semicircular plan form of the car and wheelbase.It's just arbitrary,but as identical as I can get to the Aerodynamic Streamlining Template Part-C,which was the premise for the 'Baby' project.According to some of the public domain information,they'll be plenty good for steering the air around the tires.
* As to the exposed wheels,the next step is to glue in balsa-wood sides to completely enclose those open spans.Then dope,and Bondo.These fairings have been the most difficult parts to work with due to their small size,and I needed to wait until they were attached to the belly to complete them.

[aerohead]

*the wheel fairings are essentially complete and attached.
*I need to Bondo all the screw holes and other imperfections in the belly pan,sand that down,then do automotive primer.
*then I'll create fillets around each fairing base to kill the hook vortices that would otherwise form there.I'll just use DAP,ALEX,35-year caulk.It's water based and easy to tool with a wet thumb or fingertip.
*I've got balsa wood to close the gaps in each fairing which expose the wheels.Glued,doped,, Bondo'd,and primed,the fairings should shield the tires fairly well.
*I've got to leave large gaps around the bottom wheel openings to allow 'Baby' to be mounted to a ground board at DARKO.Her wheel track isn't wide enough to allow direct attachment to the load cell uprights.I'll try and tape these openings once she's attached.
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*the fiberglass faux '1-wheel trailer wheel' is done.I layed up 1-side plus the tread surface area,dressed that part,then flipped it,taped it onto the tire and layed up the remainder,creating the full 'tire.'It weighs maybe an ounce.
*I'll soon begin the wheel fairing which the faux wheel will be bonded to.Added and dropped at DARKO will allow us to glimpse the aerodynamics of a 1-wheeled,full-boat-tailed,gap-filled trailer,as BamZipPow has created.
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*Bondo-ing and shaping of the body and stinger continue.I picked up my 3rd gallon the other day.Plus a pack of #80 sanding discs.
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*Got all the Toyota error codes now.Have an OBD-1 scanner.And starting fluid.Plus watched some You-Tube tutorials on diagnostics.
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*once I get the hood blister off,flipped,and fiberglass'd underneath,I'll be ready to look into Spirit's mechanical/electrical issues.She broke down under the shade tree and I really can't work on her aerodynamics there.
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* I have a few new photos.Maybe Al will be able to help me with that before closing time.

[aerohead]

* here,I've taped and waxed the tire/wheel/MOON and laid up directly onto it.

*after 2-hours I popped off the part,

after trimming,I taped it back on ,then laid the remainder,joining the two into the complete 'fake' wheel.
*here's the lower body/chassis on it's side,getting polyester dope and Bondo.Wheels are bagged to protect them from drips

*with fairings Bondo'd,they get screwed down in anticipation of adding balsa wood side gap sealers,and fillets.

* Same for the stinger

[gumby79]

Iyou may find theas "pop nut"s handy for in setting nut in things. I used them to attach my lift struts to my 1"sq tubing

Good work the lead up has made the excitement allthe much more ... I'm glad you postponed the tunnel . I think we will get a better education this way Vs if we had rushed you,not that we can rush an injured back .

[freebeard]

Perhaps I'll better understand the fake wheel later. It goes on the bottom of the swinging boat tail?

What radius will you use on the filleting? I've always thought there would be interference drag between the front and rear sponsons. Maybe it could use a saddle-shaped fillet in there?