Boat tail easy
 

What would be the cheapest way to attach and make a test boat tail for my Ioniq? For speeds less than 70 mph. It would be nice to do some cheap ugly mock up tests before trying to build one that’s a better quality material and painted properly with a rear hitch attachment.

I just want to do some aba testing with something super cheap and less than 5 bucks total.


Also to anyone who’s made a boat tail, describe the difference you “ feel” in the car when driving with the boat tail attaches

Less than five bucks? LOL, I thought I was a cheap *******

Coroplast political signs, including the lumbar supports to create the frame, and other various materials you happen to have laying around the house?

Don't be a menace to others. If I cared to I could find threads about aero mods blown off and laying in a ditch.

So use bungie cords. :)

CAD will only approximate a properly faired and finished version.

Five dollars ? You can't even buy a roll of tape for that much anymore.
My first thought is to mock it up in CAD and run CFD on it using freeware programs.

I'm trying to be patient with Blender. The power is there, it just needs to be directed toward CFD.

An interesting development for the coming year is Blender apps. This will mean that the casual CFD user won't have to face the entire Blender interface. It can be tailored to the task at hand.

edit:
I just got back to that. At 13:43 in a discussion on Simulation Nodes he shows a vortex street. It sounds like hair simulations might produce streamlines.

I was just thinking of duct taping some cardboard onto the car lol

That might work. I'd say make something like this with sheets of cut cardboard and then try to wrap more cardboard around it. You might be able to find cardboard for free at a recycle center or behind a store or restaurant.

https://media.wired.com/photos/59336...l-metro-02.jpg

'duct tape'
 

Have you watched the 'THINK FLIGHT' YouTube of the aero-modded Subaru Impreza ?
He tested at 65-mph, with no 'events.'
I highly recommend some sub-structure, firmly attached to the car.
On the CRX, the cardboard mockup was fiberglassed to become the final boat tail.
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On the car or truck, the ride becomes as with a limousine. Rock solid, and unflappable in crosswind, gusts, or bow-shocks off 18-wheelers.

What’s the impact difference between tapering just the roofline versus tapering the sides too as a full boat tail? I noticed all the eco modders taper all directions for their boat tails. Makes sense. But what about if I just extended the roofline and didn’t do too much to the sides? Think Mercedes EQXX or the light year zero. The sides of the rear only have a super small taper that isn’t very noticible, the main thing is their rooflines going down and extending

How much CD drop would I see just be extending down my roofline while only lengthening out the sides like those cars?