Need opinions on a potential aero mod.

[5speed5]

My truck, 2005 Chevy Colorado, has a two piece air dam under the front
bumper. The lower piece looks very aerodynamically inefficient, but I know
looks can be deceiving when it comes to that. Here are some pictures of it:









My question is, do you guys with more experience think I should remove that lower piece for better aerodynamics, or will it end up being worse?
Thanks for any opinions.
-Tim


BTW, here is what my truck looks like now without rear toolbox and with smooth hubcaps:

[spydyr]

The only way to determine the effect of the current air dam is through ABA testing.

I would keep the flat rims, and add a cover to the bed.

[5speed5]

Originally Posted by spydyr

The only way to determine the effect of the current air dam is through ABA testing.

I don't have a ScanGauge and an ABA test over several weeks with full
tanks of gas would be fraught with too many variables (among them, the rapidly cooling weather).

I would keep the flat rims, and add a cover to the bed.

Yes, in fact, I'm making a tonneau cover as we speak. Just waiting for
the spar urethane to dry before moving on. Other plans are lowering
2 or 3 inches, electric fan (stock is a mechanical clutch fan which always
provides some drag on the engine), and partial grill block. Hoping to get
above 30 mpg with all that.

[saand]

I am not an expert on aerodynamics but ill put in my 2 cents.

I had a similar "feature" on my car and i removed it but only when i did a under belly pan.

I think that it will be useful to cause an air block for the rough underside of your car. This would stop fast air running over all the components under the car. I guess it is more efficient to have a single place where the air is parted compared to multiple places under the car where the air causes turbulence many different places.

So if it was me id take it off and put in a under belly pan, if you are not going to do this then id suggest keeping it or maybe replacing it with a smoother curved block that guides the air lower rather than just pushes it out of the way.

[winkosmosis]

It's probably better with the air dam, that's why GM put it on.

I removed the air dam from my XJ when I put on a skid plate, because I figure funneling air below with the skidplate is just as good if not better, but who really knows?

[winkosmosis]

You get 29mpg???

[dmac257]

Originally Posted by 5speed5

My truck, 2005 Chevy Colorado, has a two piece air dam under the front
bumper. The lower piece looks very aerodynamically inefficient, but I know
looks can be deceiving when it comes to that. Here are some pictures of it:

My question is, do you guys with more experience think I should remove that lower piece for better aerodynamics, or will it end up being worse?
Thanks for any opinions.
-Tim

I am getting ready to add a dam and belly pan to my dodge dakota. Waiting on some advice about the combo. I read that if you put a pan under engine that it should begin at bottom of the dam .. elsewhere I read that the dam should be as low as clearance allows and the pan under as high as possible.

I am waiting for aerohead to do some testing on his civic before I start cutting up my coroplast.

Check the thread http://ecomodder.com/forum/showthrea...tml#post192785

Are you making an aero bed cover or just flat one?? I am going to get rid of my flat one and build a new aero cover.

Don

[5speed5]

Originally Posted by winkosmosis

You get 29mpg???

Yes, for the last two gas tanks anyway (540 and 538 miles). It's probably going to go down quite a bit as the weather cools.

Originally Posted by dmac257

Are you making an aero bed cover or just flat one?? I am going to get rid of my flat one and build a new aero cover.

Just a flat one for now.

[Varn]

Excellent mileage. How many miles were off road and in 4wd?

[5speed5]

Originally Posted by Varn

Excellent mileage. How many miles were off road and in 4wd?

That's a loaded question, isn't it?

The answer is "none", of course. I only wanted the 4WD for winter time (we
get out-of-the-blue blizzards here a lot at 7200 ft. and driving a RWD pickup
in snow is the worst) and we need a truck for all the landscaping/gardening
my wife likes to do (hobby).

It's not my first choice for a daily driver (much rather have an Cobalt XFE),
but I'm trying to make the best of it. I console myself with the knowledge
that not only am I getting decent economy with it, but I'm keeping it out of
the hands of someone who might drive it 50+ miles a day at 20 mpg. (I live
only 8 miles from work.)