Air Dam??????

[misslemanid]

Ok. I've seen quite a few photos with mid 70's burbs and blazers with air dams under the front bumper. Where can I get one?
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[tobiahr]

http://www.lmctruck.com/icatalog/csb/full.aspx?Page=24

[misslemanid]

Thanks! But I see that the only years they sell those for are 81-90. Will they work on a 77 bumper?
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[tobiahr]

i cant remember how different the bumbers are between the 70 and 80s models but the air dams are pretty flexible so they may work even if the bumpers are different. i've seen a few at salvage yards so you may be able to pick up a broken one cheap for a test fit before buying new.

[WarBeard]

They mounted to the frame on the 70's truck's. They were also 3 pieces.

One main piece bolted to the frame and two pieces (one on each side) bolted to the front of each wheel well.

[Ford Assassin]

What was the point/function of the front air dam? MPG?

[tobiahr]

Originally Posted by Ford Assassin

What was the point/function of the front air dam? MPG?

why not? anything to help the aerodynamics of a brick being pushed through the air at 55 to 70 mph. I've often wondered the same thing myself. I always liked the look whatever the intended function.

[Ford Assassin]

Originally Posted by tobiahr

why not? anything to help the aerodynamics of a brick being pushed through the air at 55 to 70 mph. I've often wondered the same thing myself. I always liked the look whatever the intended function.

I asked because I wasn't sure if it had an actual function other than purely cosmetic.

I owned a 3rd Gen Camaro and its front air dam was there for the sole purpose of directing air into the radiator, especially at highway speeds. It wasn't for MPG or cosmetics.

[special-K]

First thing I did on my '90 Blazer when I got it was take that ugly thing off. How the heck is that thing going to help aerodynamics on a shoe box?
Did you want a factory extra piece of plastic or something to add style? There are fiberglass ones made that at least do something for the looks,if that's what you're into:
http://www.superiorcustoms.com/spoilermain2.htm

[misslemanid]

Originally Posted by special-K

First thing I did on my '90 Blazer when I got it was take that ugly thing off. How the heck is that thing going to help aerodynamics on a shoe box?
Did you want a factory extra piece of plastic or something to add style? There are fiberglass ones made that at least do something for the looks,if that's what you're into:
http://www.superiorcustoms.com/spoilermain2.htm

To answer your question, yes I want to add a little style. I also want it to be factory as my burb is almost completely factory as it sits. I just wish I could find a factory style air dam for a 77.
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[tobiahr]

and still nothing listed for his 77. he's right, there are no factory style air dams for the 77's

[motornut]

and when the bumper changed in 89 so did the dam

[Keith Seymore]

Regarding function:

For those airdams that are positioned under the radiator support the function is to direct air through the radiator to aid in powertrain cooling.

If you see an airdam at the leading edge of a vehicle (like the 81-87 dam under the bumper) it's for aero - and therefore fuel economy.

K

[special-K]

Yeah,but I don't believe they did anything noticeable for fuel economy. I think they were more for public perception purposes,to make people "think" they would be getting better economy,just like the body change in '81. I have never noticed a change in mileage by lifting a truck higher off the road. If anything,the under bumper air dam adds more mass to break the wind with and blocks more air flow to the drivetrain. The under core support ones make sense to increase air flow up into the engine compartment.

[tobiahr]

but then again until mythbusters everyone thought dropping the tailgate saved gas too

[Keith Seymore]

Originally Posted by special-K

Yeah,but I don't believe they did anything noticeable for fuel economy. I think they were more for public perception purposes,to make people "think" they would be getting better economy,just like the body change in '81. I have never noticed a change in mileage by lifting a truck higher off the road. If anything,the under bumper air dam adds more mass to break the wind with and blocks more air flow to the drivetrain. The under core support ones make sense to increase air flow up into the engine compartment.

It's measureable in the wind tunnel (in terms of drag) but may not translate into measureable real world fuel economy. You know we wouldn't spend the money if it didn't do something for us. I don't know that the body change in '81 was ever touted as a fuel economy improvement; just a "facelift" during a mid-cycle enhancement AFAIK.

I've never lifted a truck but we did see a 1 or 2 mpg improvement from lowering dad's pickup and 5th wheel trailer.

K

[special-K]

I knew the thing about the tailgates years before Mythbusters ever existed .

I think GM would spend what little those air dams cost if it helped sales due to people "thinking" it helped fuel economy. The market had become largely about fuel efficiency by the late-70s. I do remember the '81s being largely advertised as being more fuel effiecient and aerodynamic. Figure Ford had come out with their new body with the square edges carved off,sloped windshield,no roof lip,etc in 1980. Fuel economy was a big competition back them with 6cyls on 2305s being pushed. tire diameters got teeny and gear ratios tall as a house.
I don't have an ad saved about the aerodynamics,but here's a quick one I had about fuel economy:

[russgt]

LOL, most new trucks cant even get that

I have an air dam off of an 80 if you need a picture of one.

[68Timber]

It'd be interesting to know the specs of the Chevy Special Economy Truck. I don't recall the truck. Wonder if Keith Seymore does?

[mongoose]

Originally Posted by special-K

Yeah,but I don't believe they did anything noticeable for fuel economy. I think they were more for public perception purposes,to make people "think" they would be getting better economy,just like the body change in '81. I have never noticed a change in mileage by lifting a truck higher off the road. If anything,the under bumper air dam adds more mass to break the wind with and blocks more air flow to the drivetrain. The under core support ones make sense to increase air flow up into the engine compartment.

stock height or higher... yeah i can't see it amounting to a lot if any.. tho on lowered trucks.. my air damn is like 3 inches off the ground.. it'll help a lot, the less air under the truck the better... making the underside a low pressure and pushing the truck down a tiny bit.. making it a tiny bit more stable at 'highway' speed and also a tiny bit more fuel efficient.

[misslemanid]

Originally Posted by russgt

LOL, most new trucks cant even get that

I have an air dam off of an 80 if you need a picture of one.

Absolutely. I'd live to see a picture of one. That way if I decide to build one, I have a little something to go on. It's pretty apparent I won't find an oem or aftermarket replacement.
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[Keith Seymore]

Originally Posted by BRUISER

It'd be interesting to know the specs of the Chevy Special Economy Truck. I don't recall the truck. Wonder if Keith Seymore does?

I don't remember those - I was only familiar with them through this site.

K

[russgt]

Here are the pics. It was off of a 1980 K20 with 61k on the clock