do airdams increase mileage any?

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sc2dave
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do airdams increase mileage any?

Post by sc2dave » Sun Aug 21, 2005 2:48 am

do airdams increase mileage any? you know, the ones that go under the front bumper? airdams or spoilers, whatever their called

Mouse

Post by Mouse » Sun Aug 21, 2005 5:49 pm

Hard to say on your application, but on my Mustang, an air damn helped keep the nose down at the drag strip improving my MPH and ET.

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Post by sc2dave » Sun Aug 21, 2005 9:10 pm

i want find ot for saving gas, not for racing at all

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Post by jacksoni » Mon Aug 22, 2005 9:58 pm

Air dams may help reduce front end lift ( transtlates to drag) and does help keep air out from under the car where there is a lot of drag. As Mouse said above car went faster and didn't lift as much. Anything that reduces drag will help mileage as it take less power to move the car. Power required goes up as the cube of the velocity, drag going up as the square of the velocity so reducing drag is a biggie. However, real world gas mileage is a function of a ton of stuff so would be hard to tell without very careful records. But with gas at $3 a gallon and headed up, anything that helps may be worth it. But you are not going to see a 10 mpg pig jumping to 30 mpg Honda like stuff. If I recall you are running a Saturn? You might get a bit at highspeed highway but doubt would seen anything noticeable around town.

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Post by MadBill » Tue Nov 15, 2005 10:36 pm

Down to a certain ground clearance, dams usually do help by reducing the turbulent flow under the car. Depending on underbody configuration, radiator exit airflow, etc., too low a dam can start to increase the drag again.
On a road car, you can dial it in via coast down tests: On a straight, level road, time the interval from say 80 to 50 MPH in neutral several times in each direction, throw out the highest and lowest in each direction and average the rest. Tape on the MK I air dam and repeat. Make it 1" deeper and do it again, etc. On my Geo Metro, I used plastic garden edge 4" wide and added over 3 MPG.

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Post by sc2dave » Tue Nov 15, 2005 11:11 pm

any pics,that sounds interesting

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Post by MadBill » Sun Nov 20, 2005 8:42 pm

(Damn; thought I'd replied to this! Must have blown it away by mistake.)
Sorry, no pix. After 368,000 km. & 17 years the little 3 banger has gone to the big parking lot in the sky. I should calculate my lifetime fuel savings vs. say a 4x4 truck; I got as high as 62 MPG (Imperial) commuting 50 miles (all highway) in the summer, and the least was mid 40s in the winter.
The material I used was black plastic, about 4" wide x 1/16" thick, with a nice rolled lip along one edge. It came in about a 10 ft. roll and I just bolted it to the lower edge of the existing air dam.

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Post by katman » Mon Nov 21, 2005 11:02 am

Plastic edging from the garden supply works great!
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Post by brett w » Thu Dec 08, 2005 2:02 pm

I just put one on my civic after I knocked of the factory lip. The one I built is 2 inches deeper than the stock lip. I haven't really notice an increase in gas mileage, but I haven't done any extended highway cruising either. I can tell you that the engine doesn't seem to be working as hard at 70+mph. Doesn't sound as "thrashy" as it used to. The car doesn't seem drift and be as affected by wind gust. It also seems to stick a little better in some turns. May just be in my head. I built a similar airdam for our race car and we had to change the rear springs to compensate for the increased front wieght transfer.

Of course I can tweak my fuel on the highway. It is not problem for me to lean it out at cruising speeds to increase my mileage. I am going to do a little highway driving here over the holidays so I will let you know if there are any improvements.
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Post by MadBill » Thu Dec 08, 2005 4:03 pm

When we stuck one one my pal's GMC van years ago, we just made it a very low hanging flat aluminum plate and then trimmmed it until it didn't scrape too often. It not only helped mileage, it also reduced wind noise a bunch, especially in the 40 -60 MPH range.
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