Is 42mpg too low a goal?

[Istas]

I got half the air dam on, and I took a picture that looks too cool to not share.


Nighttime adds extra awesome. I must make a mental note to clean off that duct tape residue though.

[NeilBlanchard]

Looks great -- I hope to replace all my Coroplast with aluminum, too. I like having it noticeable -- then people ask me about it. In the future, I can always paint it...

[aerohead]

Originally Posted by Istas

I got half the air dam on, and I took a picture that looks too cool to not share.


Nighttime adds extra awesome. I must make a mental note to clean off that duct tape residue though.

The dam looks kinda low.Bondo ran into trouble with his on the F-150 and ended up trimming it back even with the elevation of the lowest suspension component.That got his mpg back up.

[Istas]

*nods* it's about an inch lower than it will be when it's done, I wanted to fit it to the bumper before bending the bottom edge under as the support/attachment for the undertray. And, I'm doing my best to have it be even with the underside of the car:


It's hard to tell, but I'm thinking about 2.5 inches is about how far down from the bumper the lowest parts of the car are. Also, the fact that this is almost a grass driveway doesn't help give accurate ground clearance pictures.

Right after I post this I'm going to put the other side of the dam on, then I'll take both sides off, bend the edge under, put them back on (snipping the ledge when needed for the curve), then I'll start delineating the cut marks on the undertray sheet metal.

And I test-drove this yesterday, just to make sure; even with the center unsupported like that, this still didn't bend (to the point of holding the deformation, anyway) at speeds over 70 mph. With the undertray behind it and extra screws, I'm thinking (that is, hoping) it'll be fine.

[NeilBlanchard]

Hi,

Maybe if you leave the outside corners lower than the center -- to roughly match the lowest bits under the car? The suspension lower 'A' arms slope down to the wheels, which is where the curve will support the spoiler. And you won't increase your frontal area.

[Istas]

Neil, that's a good idea, but I'd rather not mess with the dam and undertray that way. Instead I'm going to add the deflectors separately, so I can test different designs (hopefully with my MPGuino, which I don't have wired yet).

Here's pics of the airdam completed. There's a clearance of about 7 inches or more between the bottom of it and the road. Given, it still reduces the clearance when starting the car up an incline or going up driveway entrances or whatnot, but I knew that would happen going into this. I'll just be more lenient about going over things like those.


This one's from far away and close to the 'level' line straight forward from the car going from the lowest parts of the center of the car to the bottom of the airdam, to show how close I got to the optimum airdam height. It's not perfect, but it's close enough for me.


And a final one from Car's "bad side", that shows my first try at Bondo to repair a rust hole. I didn't like it much at all, and was too lazy to sand it.


I haven't decided what I'm going to do with the trailing edges of the airdam, on the sides, but they're out of the way for now. Next up is the undertray.

[Istas]

Tray is cut out and attached to airdam, but it needs a support bar. I'm done feeding the mosquitoes today, so I'll just work on attaching the support another time.

Here's the airdam-tray combo off the car.

[skyl4rk]

Nice work

[Istas]

Okay, partial tray under the engine bay back to the wheels is installed and functional.

From the front:


Can barely see it, which is the idea. Now a "before" shot from the side.


And "after", with the tray on.


From the front, passenger side. The downward bulge visible is where one of the screws holding the angle bracket to the support bar loosened up on the first drive. I'm going to be putting a second nut on each of the screws to stop that from happening again. Hopefully.


I bent the parts in front of the wheels down to give clearance for the wheels, rather than trimming them right away. I'm definitely going to put a vertical panel in in front of the wheel though.

[Istas]

Here's a better picture.