Effects Of Air Dam (Ford F350 pickup)

[ECONORAM]

Originally Posted by Big Dave

Aerohead is probably right. Anair dam plus a belly pan would give the best MPG.

I modified my air dam this summer. It was 3 inches above grade and it grounded at the least provocation (like braking or the steps in my driveway). It worked really well. It was worth at least 0.75 MPG.

But I got tired of listening to it grind, so I shortened it up to 9 inches above grade.

Now it doesn't drag or look dorky, but it is nearly worthless in improving MPG.

I'm trying to learn GIMP so I can shrink down my pix to a size the site can handle.

Very interesting. I've not put an extended air dam on my truck, but after reading this I might have to try that. I also plan to drop mine about 2 inches. Both should help in the MPG arena...

[bullmtl]

Originally Posted by Cd

Three miles per gallon ?
That's incredible !

I mean if you had a car that got fifty miles per gallon and noticed a +3 MPG improvement, I'd be impressed ..... but you are starting out with a truck that gets less than half that.
That is a huge change in fuel economy !



No one cought the Nice/ICE road trucker caption ?? NAH ...surely not.
I caught it and I haven't even seen the show ! I think everyone gets it , but they just don't mention it.
Again .. clever play on the name there.

Imagine a world where they didn't screw w/the fuel[100mpg^even the pickups]

[Cowboy_Dan]

Originally Posted by Big Dave

Max:
I am on my second iteration of air dam. The first one extended to within 1.5” of grade and got the 27.00 by itself. I also had side skirts where the running boards used to be. They approached 3” of the ground. Air dam & skirts that low dragged the ground a lot. No damage due to the fact they were ripstop conveyor belting but an annoyance all the same. With the air dam that low I probably lost some CdA due to increased frontal area.

Second iteration, I ditched the side skirts (more trouble than they were worth) and raised my air dam up to 6” above grade in front of the wheels and 9” above grade in the center (just covering the steering tie rod). MPG drifted back into the mid 26s. This setup obviously never drags or fouls parking curbs. It passes over most road kill.

Gonna try again, splitting the difference. Probably 3.5” in front of the wheels and 6” in the center.

Any update on the air dam? I'm building one somewhat similar.

[kach22i]

Originally Posted by Cowboy_Dan

Any update on the air dam? I'm building one somewhat similar.

I sent a PM to him, maybe we will get some photos.

See the link in my signature on building your own chin spoiler. It is good for an extra 3-mpg on the highway.

I have plans on lowering it even more. Right now it goes over curb stop blocks.

[Big Dave]

No progress on the air dam. RL gets in the way.

3 MPG is impressive.

[kach22i]

Originally Posted by Big Dave

No progress on the air dam. RL gets in the way.

3 MPG is impressive.

That number was for the summer (and early fall) of 2009, I lost 1-mpg with the rear spoiler but like the downforce. I lost another 1-mpg with the rubber wheel arch flare lips. I'm only up 1-mpg at this point.

My chin spoiler is 7-1/2" from the ground. I can go over parking stops, which is nice because even I inch up too far once in a while. The plastic lawn strip is 6" high, which will leave me 1/2" to screw to, just enough should I double it and extend downward. At 2" of ground clearance it is similar to 0" of ground clearance from what I've read.

The 2" clear will be similar to my 1977 Porsche Targa 911 with chin spoiler. I've scraped it a few times, but never hit something like a curb stop.

I plan on removing the second chin spoiler on my S-10 for snow. I'm thinking of using butterfly nuts so I can take it off without tools should some idiot back up into me or something.

[ICEBOX]

I drive a class 8 tractor and get 18 mpg without a trailer

[kach22i]

Originally Posted by ICEBOX

I drive a class 8 tractor and get 18 mpg without a trailer

That blows my mind.

Is there anything special you did to it in order to get those results?

Review of the U.S. Department of Energy's Heavy Vehicle Technologies Program


A photo would help.

[radioranger]

thanks for the truck testing, I once ran a small boat on the back of the truck to the shore and the truck seemed to cruise along easier, now I know why , got to find another 8 ft rowboat, cheaper and easier than the cover and you look like your going fishing !! plus you can !

[radioranger]

I wonder how much of the air dams effects are from kicking the air around the side of the truck more smoothly and actually keeping it closer to the body instead of kicking the air way out but judging by your results it seems the under body airflow is a bigger factor than I thought, thanks for the air dam info , going to add a bigger air dam to the stock plastic one on my 88 brick ranger, best average MPG is about 26 , very very wind dependant.