5th generation civic hatchback - improving aerodynamics

[AndrewJ]

How 'bout an UN-installed, UN-assembled Super MID?

I have a picture of one of those

[budomove]

The work you have done to his car is amazing, and to think the cd is better than the insight, and you have FOUR seats, AND cargo space!

[AndrewJ]

Originally Posted by AndrewJ

---------------------------A(stock)----B(aero)---A(stock)
Initial speed-------------55mph-----55mph-----55mph
Slowed to----------------52mph-----55mph-----52mph
Miles@lowest speed-----0.375------0-0.4------0.375
Top speed---------------66mph-----71mph-----65mph
Miles@top speed--------1.1---------1.05-------1.05
Miles@55mph (end)-----1.35-------1.45-------1.25

Had another run down the test hill yesterday when I was working. I had my best ever run. Terminal velocity was 74mph, "Miles@55mph" was 1.55

Unfortunately I didn't have time to turn around and do another run (I was on the clock after all)

Oh, and on this latest run I had the disc wheelcovers and the Kammback which weren't there on the initial A-B-A tests.

[Cd]

AndrewJ : This has quickly become my favorite thread. I am especially excited by the rear spoiler extention that you have created.
Several months ago, I created one myself that was identical to yours in every way.

Would you be so kind as to explain how that the struts are removed ?

Looking forward to more of your testing.
One more question : Does your car have a belly pan, or just the air dam ?
I have a belly pan and a partial dam in front of the front wheels ( whisker spoilers ) - this way I dam the air from the tires, but do not add all of that extra frontal area.
I'm curious how much of a drop in your .CDxA that you could get by doing something similar.

Thanks for the inspiration !

[Cd]

Just curious : did you ever happen to see the pictures that I posted of my tuft testing ?

I don't know if they could help at all.



( I can post images of the test later )

[MetroMPG]

Tuft testing! I love it.

Did you take video as well?

[aerohead]

The front airdam is so low,I'd be concerned that it is aggravating frontal area and increasing drag.For other cars tested,they found that if the dam projected below the elevation of the bottom of the lowest suspension component,that drag would begin to increase,erasing the drag reducing properties of the dam,actually lowering performance.It would be a shame for your clean fabrication to detract from the Civic's mpg.

[MetroMPG]

Every time I look at Andrew's air dam I think the same thing... "it must be too big!".
But his coastdown testing shows a significant improvement.

The air dam is similar in size to the one on Car and Driver's crisis-fighter Pinto, which they measured as worth a 6.25% increase in MPG at 70 mph. It's equally as massive, with only 2 inches of ground clearance (which must be well below the lowest hanging underbody components):

[AndrewJ]

While mine certianly looks massive, I was surprised to find out that when measured it only portrudes 3" down from the OEM lip (in the center). On the sides, where the tires and lower-control arms are sticking down the airdam sticks down 5"

Cd: I'll be working on the car today so I'll try to get pics of the strut dissassembly for you. THe main problem I ran into with it is that the parts that mount through the glass get deformed over time, so you have to take it easy to avoid stripping the threads.

[Cd]

Originally Posted by MetroMPG

Tuft testing! I love it.

Did you take video as well?

If you remember, a while back I posted more images at our sister forum ( Gassavers )
I changed my username on this site to something less weird.

The video that I took was really rough since I was freaking since I was overly self concious ( And I wasn't even the one driving - we were just in the chase car ) Also at the time I only had about 30 seconds worth of video on the SD card. I was trying to make the best of what little time I had so I was jerking around trying to show as much of the car as possible.

It was useless really.

The test was done before I had done anthing to the car except relocate the front licence plate to act as a partial grill block, had more aero hubcaps on and I had the mirror pulled back.
Besides, I don't know how to go back and hide the licence plate in the video.

I plan to do a follow up tuft test in a few weeks ( vacation )