Boattailing the Prius (nope, I'm not dead)

[Rishar]

Been a little while. I did a few mods and stopped. Some real life stuff happened that made it difficult for me to do much of anything. However, in preparation for summer I made a small template for what I will be aiming for this summer. So look forward to it! Any thoughts on this design are of course welcome.




And for reference.


Essentially, I want to plan this out as much as I can right now before summer so I'll be able to hit the ground running.

[Daox]

Looks good. IMO the Prius is totally ready for a boat tail (and any other load reducing mods). With its CVT, its completely capable of 'regearing' on demand and taking the most advantage of the modification.

[Vman455]

I'll be watching with interest. I've been toying with designs using a hitch-mounted cargo rack as a basis for a boattail; how do you think you'll attach yours?

[aerohead]

I was looking at your second image,with the 'Template' overlay.
It looks like there's a discrepancy between the height of the Prius,and it's position of a max. roof camber,and the corresponding point on the 'Template.'
This area is extremely important to the boundary layer.
I recommend that you reexamine the overlay.
Anything you put back behind the car is going to help,but if you get it 'right',you'll get the biggest bang for your buck.
And you're looking at a few hundreds of hours of work to create the tail.You sure don't want to do it over.

[Rishar]

Originally Posted by Vman455

I'll be watching with interest. I've been toying with designs using a hitch-mounted cargo rack as a basis for a boattail; how do you think you'll attach yours?

There's a few attach points. There are 5 under the hatch spoiler. I'll be removing the tail lights from their current location and using mount points that are behind them. I'm not sure about lower. I'll be removing the bumper at a later time (not difficult as it turns out) and looking behind it for the lower points.

Originally Posted by aerohead

I was looking at your second image,with the 'Template' overlay.
It looks like there's a discrepancy between the height of the Prius,and it's position of a max. roof camber,and the corresponding point on the 'Template.'
This area is extremely important to the boundary layer.
I recommend that you reexamine the overlay.
Anything you put back behind the car is going to help,but if you get it 'right',you'll get the biggest bang for your buck.
And you're looking at a few hundreds of hours of work to create the tail.You sure don't want to do it over.

I certainly would not want to do it over, you are right about that Aerohead. What I did was mostly just a way to extend the current contours of the Prius. Not quite right as you pointed out. Though I'm not sure how to line it up so it is right on. Based on how it reads "I think" it goes like this?



Which would be way off as far as a streamlined rear end with that overlay...which makes me think I'm doing it wrong.

Or this one which is 'mostly' lined up.

[aerohead]

Originally Posted by Rishar

There's a few attach points. There are 5 under the hatch spoiler. I'll be removing the tail lights from their current location and using mount points that are behind them. I'm not sure about lower. I'll be removing the bumper at a later time (not difficult as it turns out) and looking behind it for the lower points.



I certainly would not want to do it over, you are right about that Aerohead. What I did was mostly just a way to extend the current contours of the Prius. Not quite right as you pointed out. Though I'm not sure how to line it up so it is right on. Based on how it reads "I think" it goes like this?



Which would be way off as far as a streamlined rear end with that overlay...which makes me think I'm doing it wrong.

Or this one which is 'mostly' lined up.

The upper image looks correct.
The offset in the contour makes for more work.
I did flying buttresses on my CRX to 'blend' into it

[Rishar]

So, may be looking more at the top one, which would require building up on the back as well as out. And here I thought the Prius was supposed to be Aerodynamic already :P

[freebeard]

http://www.fixya.com/cars/t8964534-step_step_instructions

[Rishar]

Originally Posted by freebeard

http://www.fixya.com/cars/t8964534-step_step_instructions

Yup, that's almost the same diagram I found but from a different angle

[Vman455]

Originally Posted by Rishar

So, may be looking more at the top one, which would require building up on the back as well as out. And here I thought the Prius was supposed to be Aerodynamic already :P

Tuft test it first, otherwise you're just guessing what the airflow is doing now. I'm betting you'll find there's attached flow all the way down the back.