Desgeegee's Build Thread Ford Focus
 

Hi to everyone!
First of all, i'm apologize for my english (i'm italian), and i hope this is the right section.
I've got a Ford Focus 2016 hatchback diesel and despite it's very thrifty in consumption i wanted to improve aerodynamic.
The first thing that i did, was to look down the underside of tha car and what i saw scaried me a lot. there weren't panels or anything else except a little diffuser, two mini panels near the rear wheels, four spats and, of course, an undertray.
Here the underside of my car (photo by google):
[IMG]https://ecomodder.com/forum/member-d...825-cybm6r.jpg[/IMG]

So the first thing that i did after that thrilling vision, was to search what ford did in the "Econetic" version about aerodynamics mods, that is to add a paneling to the underside and equipped the steel wheels with a smooth hubcaps. I bought these panels and i mounted them.
https://ecomodder.com/forum/member-d...4-18-53-15.jpg

Here there is a photos of a Focus with all panels (photo by google):
https://ecomodder.com/forum/member-d...download-1.jpg
In the middle of multilink structure, you can see a little cover of it. It's very very little.
I decided to create a carbon sheet to cover all suspension structure that then, will work with a new diffuser, more wide. i was started with making a cardboard mock-up, and this is the final result:
https://ecomodder.com/forum/member-d...4-18-56-15.jpg

I'm sorry but i don't have the photo of the underside of the car with this panels, but i made a very poor photoshop :turtle:
https://ecomodder.com/forum/member-d...6-cybm6r11.jpg


What do you thing about this underside?
Soon i will project a right diffuser :thumbup:

Focus underbody
 

Everything you cleanup under there will only pay dividends down the road. It's a good investment! Looking good! :thumbup:

Looking good.

I've been spending some time recently under my car not as bad as most cars.

Nice improvements you have made.

Thank you guys.
Last month i read some papers about the efficiency of a rear diffuser in a sedan, wagon and hatchback. In the first two types, a proper diffuser actually reduces drag but not for the hatchback.
So my question is (hoping for your knowledge): is most effective to make a simple diffuser following the shape of the original "diffuser" with the plus of cover the holes between the bumper and tyres o make a diffuser with a different inclination size etc?

I would suggest you to slightly increase the surface of the one you proposed. Eventually if you can mount on the lower arms BMW deflectors.
And close the back according to the model of the central fairing.

most effective
 

We might presume that Ford actually 'tuned' the OEM diffuser for the peculiarities of the Focus' rear flow.
Some hatchbacks ended up with a 'raked', slanted chop to the roofline, and slope angles in the 'forbidden' 28-degree- to- 32-degree range, producing bi-stable flow and 'booming' as the flow jumps back and forth between fastback and squareback flow. Plastic roof extensions were added as a palliative to atone for the original sin.
I know of one variety of Focus hatchback with Cd 0.297. This suggests that Ford designers paid some 'thought' to the car.
Without a laboratory it's hard to 'accurize' modifications, and in your case, by mimicking Ford's original diffuser profile, it might have a better probability of success. Only testing will tell.

For Ironick: yes i need to "close" the holes between the oem little panels and my "suspension cover", it's in the list of things to do. For the lower arms covers, i thing it's hard to do properly an so i want to concentrate first on a modify the diffuser.

For Aerohead: Ok, i will try to follow the original diffuser and then test it.

Thank you for your answer

Hi guys, i'm back with some little news:
- i made a cardboard prototype of the right part of the diffuser (in black)
https://ecomodder.com/forum/member-d...14-27-29-3.jpg
-i used this prototype like matrix for create the final glass-fiber panel
-i used a sheet metal with C profile with the scope of fix the panel at the spar
https://ecomodder.com/forum/member-d...2-00-08-49.jpg

And this is the final result:
https://ecomodder.com/forum/member-d...23-00-03-3.jpg
https://ecomodder.com/forum/member-d...1-23-00-03.jpg

Now i'm testing this panel on the road (bend, twist, vibration ecc) and after that i need to putty it and paint it matte black.
:turtle::turtle:

Looks good! It will hide away nicely painted black.

Of course! I also use a round head screws (shich will be painted in matte black) to hide them