100% Electric Vanagon aerodynamic

[yabert]

Hi

I have a 1980 Vanagon electric powered by a 2017 Bolt EV powertrain.
Or if you prefer, I have a transgender Bolt EV
I average 80 mpge (mpg equivalent) and I can easily do over 100-120 mpge in summer at lower speed.
Details here: https://www.thesamba.com/vw/forum/vi...737&highlight=
The pop top on our van is pure crap and I hate it so much. It's an old fiberglass piece of crap with holes, crack, etc.
To add, it is 3-4 inch's to low to stand up in the van without open it.
So I want to replace this pop top by a ridgid high roof top.
You can see the problem/challenge. How to improve energy consumption with a bigger front area?
I have to improve aerodynamic for sure and it's not so complex to do better than a stock Vanagon, but where can I start?

[yabert]

You can see I have some 3D modeling skill, but no fluid flow simulation skills.
https://www.thesamba.com/vw/gallery/pix/2441329.jpg

[freebeard]

Thanks for asking.



I don't know if the text is readable, but the high-top had a Cd of 0.40, while the Westy is 0.51. The A goes up of course. The question becomes what is fabricable (new favorite word).



The footprint is rectangular so a low-poly Cybertruck shape would be easy. Stitch and glue kayak construction could be adapted.

[yabert]

Originally Posted by freebeard

The question becomes what is fabricable (new favorite word).

Of course it's fabricable. The question is more related to what is the good shape to fabricate.
About material, I tough about 5052-H32 aluminum sheet. Laser cut parts weld in my garage.
Probably a seal all around and fix with multiple screws/bracket.

[ennored]

Strangest thing, I just read a thread about your truck on an EV forum yesterday. Now I see your post here.

I think you're on the right path. You're proposed shape reminds me of the Don-Bur trailers in the UK.

https://donbur.co.uk/ They claim less drag even with more frontal area.

That is to say. I think you can lower your drag even though you add frontal area.

[freebeard]

I think you can lower your drag even though you add frontal area

.

Add tumblehome to the high-top you propose. It need be no wider than the hatch opening in the roof.

[freebeard]

If you don't want to lose the upper bunk, the bubble top could have a pop-up that cantilevers over the windshield. Just turn this around:

[yabert]

Originally Posted by ennored

https://donbur.co.uk/ They claim less drag even with more frontal area

Yes, exactly what I want.
More interior space, but better aero at the same time.
Ok, what kind of software I can use to be sure of the shape of my high top?
Or is somebody here can help me design the perfect shape of my teardrop high top?

[freebeard]

You can lay it out with chalk on the shop floor, just put the highest point 30% of the way back.

If you need somebody, that would be aerohead.

[redpoint5]

Originally Posted by freebeard

Was wondering if this is you, but the URL says "Paul Herzoff", which I will neither confirm nor deny is you.