Air Dam and Tray (2005 Civic Sedan) - Fuel Economy, Hypermiling, EcoModding News and Forum

Harpo · 03-30-2008, 06:52 AM

So after the easy stuff (ScanGuage, Tire Pressures, Upper Grill Block, WAI) I need to start looking at Aero Mods to compliment my progress. The first area of interest is a small air dam, replacing the 1" chin spoiler. I'm hoping to incorporate some measure of wheel fairings. I'm going to look at some wrecked equipment today, and try to find some template material (old spoliers and such).

The second area of interest is reducing rear bumper drag by closing up areas with a under tray probably with coroplast. The DS rear behind the rear wheel has some easy attachment points and can be made pretty smooth transitioning out of the wheel well.

Looking for options, ideas, and recommendations. Which will have biggest bang for my time?

LostCause · 03-30-2008, 05:39 PM

Personally, I'd focus on the front control arms and forward. Make as smooth a radius as possible from the lower edge of the front clip to the bottom of the OEM airdam. From there, attach an undertray at least as far back as the control arms...but focus on making them smooth.

I think your biggest gain will be to fabricate some front wheel splitters and boat-tails...either out of reinforced coroplast, fiberglass, or some other stiff/cheap material. Radius the front edge and have it expand to where it ends wider than the wheel. In the future, a key addition will be front wheel skirts so you might as well set up for that. The same idea holds for the boat tails. Have them start wider then the wheel (but with radiused edges) and taper back at a 7-10 degree angle.

In the future, the next step would be to add a splitter/boat-tail to the rear wheels and extend the undertray back to the bumper. I'd also think about running full length side-skirts at this time.

Easiest mods at the moment would be to lose the side mirror, seal all gaps, and use a lighter weight oil w/ oil analyses (pretty ballsy, though). Welcome to the land of diminishing returns...

- LostCause

Arminius · 03-30-2008, 09:04 PM

I'll watch this with interest, Harpo, since I have the exact same car (model, year, even the color). I plan to make a number of mods to my car, too. However, they must all be pretty much covert because my wife hates to have anything even slightly abnormal on the car. I want to keep the car as appealing to her has possible because she wants to make it hers when I finally buy an electric car.

My first mod will involve buying prefabricated screens to go behind all the front openings. I will cover them with something black.

MetroMPG · 03-30-2008, 10:09 PM

Hey Harpo - nice to see you're already 33% above EPA combined.

I think LostCause has given some good advice there.

And... welcome, Arminius.

DifferentPointofView · 03-30-2008, 10:52 PM

yes, welcome.

Hmm. going covert. It's all about the clear stuff

Arminius · 03-30-2008, 11:26 PM

Thanks Metro. I'm a skeptic by nature, so I'll probably move slowly before doing any mods. The easy ones will come first, however. Obviously, a Scanguage would help, but I'm just barely over 39 combined already. I really want to get 40 on the next tank. I'll get the SG this summer, I suppose.

Daox · 03-31-2008, 10:42 AM

Welcome to the site Arminius. Where are you located in WI?

Harpo · 03-31-2008, 05:53 PM

[quote=MetroMPG;17006]Hey Harpo - nice to see you're already 33% above EPA combined.
QUOTE]

36.9% now. YeeHaaww. I had a return trip at 46.8mpg today after oil change to synthetic. No wind assist either. Just good IATs and steadfast MPG control.

Thanks guys!

Arminius · 03-31-2008, 07:31 PM

Quote:

Originally Posted by Daox

Welcome to the site Arminius. Where are you located in WI?

Hi Doax. I'm in Sussex. I drive to Brookfield to work.

After I get a mpg history as a reference, I plan to get a Scanguage (in June or July) and then do the same warm air engine mod that Harpo did, or something close to it.

Harpo · 04-01-2008, 05:52 AM

Quote:

Originally Posted by Arminius

I'll watch this with interest, Harpo, since I have the exact same car (model, year, even the color). I plan to make a number of mods to my car, too. However, they must all be pretty much covert because my wife hates to have anything even slightly abnormal on the car. I want to keep the car as appealing to her has possible because she wants to make it hers when I finally buy an electric car.

My first mod will involve buying prefabricated screens to go behind all the front openings. I will cover them with something black.

Tell her you'll spend 10% of the savings on a nice dinner.

Rummaging around the shop, I found some old Filter Foam I used as a hood to aircleaner seal for some custom cold air intakes a few years back. It's black, and I think I can cut it to precisely fit the upper grill. It'll certainly stop the high pressure air, but probably allow some bleed air at low speeds with fan operations. It'll look a bit more stealthy. I'll post when she's done.

Sandy · 04-01-2008, 09:43 AM

Nice car.
I have the '04 version.
The scangauge has almost paid for itself in 3 months.
I went from 33mpg average in December to 39mpg average now in March.
I did the lower grill block using the foam heating pipe insulation and holding it in with black duct tape. (My car is dark blue).
And the upper block is 1/2 way across, just to let in a bit of air.
I've got my dibs on some coro-plas used for political signs at our recycling center as soon as more comes in.
My drivers side mirror was whacked by a car door this winter,
and a small rectangular fish-eye mirror was added inside.
This has been great.
Except for backing up.
This is a better view for the highway than the stock mirror.
The hole where the mirror was is covered by the black tape until I make a coroplas cover.

Daox · 04-01-2008, 10:21 AM

Quote:

Originally Posted by Arminius

Hi Doax. I'm in Sussex. I drive to Brookfield to work.

Sounds nice. I'm in West Bend and drive just east of Miller Park to work each day.

Anyway, I'd like to invite you to the Milwaukee Hybrid Group meeting on the 19th of this month. Its held at the Oak Creek public library. I'm not sure what they'll be going over this month, but its a great time to meet people, get advice and info, and even get some driver training to improve your mileage. I'll be there, and I think Ben Nelson will also be comming.

aerohead · 04-04-2008, 01:47 PM

Research has shown that the back panel won't be effective if the forward area of the underbelly hasn't first been cleaned up.

red91sit · 10-26-2008, 04:44 PM

Quote:

Originally Posted by aerohead

Research has shown that the back panel won't be effective if the forward area of the underbelly hasn't first been cleaned up.

won't be AS effective, the rear ward one can still be a slight help, especially if you have a parachute style rear bumper as so many cars do.

But as far as going for the low hanging fruits first, starting at the front and working back is where you really get the benefits.

vtec-e · 10-27-2008, 01:56 PM

I put in a rear tray but it is causing a lot of condensation in the windows. Looks like it is after changing the air pressure in the exhaust vent area. I have it going through a hole in the tray, behind the wheel but the air just wont flow unless the blower is at 1 or 2. And i hate foggy windows! I'd be interested to hear peoples experiences of this and how they solved the problem. I've looked up exhaust vents etc. but have had no luck yet.

ollie