2008 Ford Focus (Hatchback) mod.

[calfianu]

Looking for a kammback for my focus:


Stock vs. Kamm:

Second version of Kamm:

maybe less invasive modification, with positive results:

[Xist]

Originally Posted by aerohead

I completely enclosed the cowl area and windshield wipers of the T-100 at the Bonneville Salt Flats and it made no measurable improvement,even at 105 mph.

Aerodynamics are a harsh mistress. It looks smoother! Many vehicles seem to almost have one unbroken curve for the hood and windshield.

[Xist]

Originally Posted by calfianu

I would like to add an spoiler on the bottom rear window like this:

Do you want that for aesthetics? I think that you would have people snickering and saying "You know that does not do anything, right?"

At least, that is what I would expect someone to say that to me. I have yet to figure out what good that is supposed to do.

Since you posted those airflow pictures, you seem to be way ahead of me already, but just in case:

Have you used http://www.weirdcalculator.com/test/aero_template/? I use that so much that I bookmarked it. This is the one that I did most recently:

In my opinion, the Civic has a very good taper, but if you see how I extended the roof and trunk lines, the deck lid would need to be extended twenty-one inches for the air to reattach.

A Kammback would be great for your hatchback, but I do not think that anything else, save a [partial] boat-tail would be beneficial.

[calfianu]

Originally Posted by Xist

Do you want that for aesthetics? I think that you would have people snickering and saying "You know that does not do anything, right?"
.

Yes, you are right. There are many "aesthetics" adds on cars that might make the things worst... I thought like this seeing elerons as extensions of SW...
But there are elerons that help even in that case:

https://www.youtube.com/watch?v=5UdROEOUyvg

This time, the apron on the bottom of rear glass, if long enough will make a difference (I think).
I think there are some other models where this apron will be less invasive and more effective than top roof kamm extension. I'm thinking on the work AndrzejM did and the shape of other models with a sport hatch (Citroen Xara, Opel astra G, Alfa romeo 146 and some other)

More, I hate the idea of template when taking about aerodynamics. There are so many alternatives, so why sticking with only one base profile..

[Xist]

Originally Posted by calfianu

More, I hate the idea of template when taking about aerodynamics. There are so many alternatives, so why sticking with only one base profile..

While every snowflake may be unique, I wonder about raindrops.

[calfianu]

Originally Posted by Xist

While every snowflake may be unique, I wonder about raindrops.

You could start writing a haiku about this

[calfianu]

My boat tail on focus based on 1939 Schlörwagen

[calfianu]

[calfianu]

39 celsius outside. Hot Italian weather. AC on.
Acceleration to 180 km/h with warm engine water temperature 102 Celsius.
Top gril block is gone.
Now same test 96 Celsius.

[aerohead]

Originally Posted by calfianu

My boat tail on focus based on 1939 Schlörwagen

Remember,this car achieved only Cd 0.186 with its pseudo-Jaray tail.Exactly what Hucho warns about,and what Kamm and Koenig-Fachsenfeld kept in mind.