Front air dam on diesel trucks [Archive] - TheDieselPage.com Forums

Cowracer

09-16-2005, 04:03

Originally posted by John J. LoCrasto:
I have one on my 99 k2500, it's the same part number as a 88-98 gasser

Johnny That air dam comes in two flavors. 2wd which is solid and 4wd which has holes for the tow hooks.

The 4wd will fit a 2wd, and the holes make great moutning locations for fog lamps.

Tim

JohnC

09-16-2005, 06:37

They came on all the trucks below 8600# GVW. It's a CAFE thang.

JeffsTowTruck

09-16-2005, 08:01

Look at my pics I think I have a front shot. I wanted a front air dam with fog lights. All the A/M companys had were 200.00 +.Way more than I wanted to spend. I went to GM dealer and was asking and found the one that fits a SS truck for 38.00.
I could not belive it. You have to remove the tow hooks. Big deal I have never used one yet.
I had it painted the color of my truck and got some used Volvo 780 4 dr car fog lights and mounted them.. Now I'm looking good. :cool:

Marty Lau

09-16-2005, 09:03

Tim;

By chance woould you have a part number for that 2 wheel drive unit. I ripped mine off for about the 3rd time last hunting seanson. So it be time for a new on.

Thanks :D

Cowracer

09-16-2005, 09:28

Originally posted by 16ga SxS:
Tim;

By chance woould you have a part number for that 2 wheel drive unit. I ripped mine off for about the 3rd time last hunting seanson. So it be time for a new on.

Thanks :D Negative on that Ghostrider!

I had it somewhere about 3 jobs ago. You local GM dealer can get it quicker than I could. Give them a call.

Tim

DmaxMaverick

09-16-2005, 10:32

Try www.gmpartsdirect.com (http://www.gmpartsdirect.com) 's online catalog. It has a pretty extensive collision parts listing.

Marty Lau

09-16-2005, 13:37

I could not find the collision parts area, but I did find the parts number on another sight.

without tow holes #15569428
with tow holes #15569430
I called the local Chevy dealer and they wanted $36 I told him I could get them from another for $31 (GMC & GM parts Dirrect) Then the parts guy said how does $29 sound. The moral to the story is you can us the GMPartsdirrect to get better prices locally and give your local dealer some support.
Now the next issue is I had the placis gismo's fall out of the driver side cooling hole in the bumper and the Chevy parts guy could not find a part number on it any idea's???

jspringator

09-17-2005, 05:51

Some guy over at the "Place" posted a 1.5 MPG increase with an air dam, although not specifically this air dam. Heck, if it got 1MPG it would be worth it! Mr Taillight has one on his site for $15.

[ 09-17-2005, 07:25 AM: Message edited by: James Springate ]

TurboDiverArt

09-17-2005, 10:00

You can also get a new aftermarket one for $16.95 from www. autobodypartsonline. com. Personally, for $15 more I'd just buy the GM one. Anyone got a picture of this on a truck? I assume it comes white and needs to be painted?

Can a 4" lower valance (air damn) really make that much of a difference?

I'm wondering if this is painted the color of the truck? I have the factory charcoal dark gray running boards and fender flairs. Truck is Red. Wondering if the air dam should be painted red, black to that dark charcoal gray color to match the flairs? Anyone know or have a picture of what it would look like on an "LT" truck?

Art.

G. Gearloose

09-17-2005, 10:29

I thought you could get any color you want as long as its black.. smile.gif
wish I didn't throw mine in the dump...

TurboDiverArt

09-17-2005, 15:55

Originally posted by G. Gearloose:
I thought you could get any color you want as long as its black.. smile.gif
wish I didn't throw mine in the dump... Isn't that the Powerchoke?

I think I saw a pick-up tonight with one. Was red like mine. The air dam was black and matched pretty much the fender flares. Looked nice. If it comes in black I

JeffsTowTruck

09-17-2005, 16:51

I know they look good but helping get gas miles :confused: I would think is a stretch.
Gm ones do come any color as long as it is black. :D I painted mine.

TurboDiverArt

09-18-2005, 16:10

Originally posted by JEFF'S TOW TRUCK:
I know they look good but helping get gas miles :confused: I would think is a stretch.
Gm ones do come any color as long as it is black. :D I painted mine. Sort of my thought. I figure if it costs us $30 to buy one direct from GM and the aftermarket sells them for $15, what does it cost GM? Even with assembly labor and paint, it can

jbell

09-18-2005, 18:36

I might be the guy referenced getting 1.5mpg better. I have recored mpg averaged over several thousand miles. However my air dam is lower than the factory 4". I have mine extending down a little over 6"

The simple answer is that you pay a bigger mpg penalty on the aerodynamics of the rear of the vehicle vs. the front, as well as all of the turbulence at the bottom of the vehicle. It takes less hp to push more air out of the way with a big front air dam, than pay the turbulent air flow drag underneath.

Aerodynamics is THE biggest penalty above 45mph. As I run 75 all the time on my commute, aero is my enemy.

Now if you want something interesting (which I haven't done yet) is to get some airtab.com vortex generators, and put them on the back of a surburban. Tractor trailer, and RV owners swear by them for wind stability and mpg reasons.

Cowracer

09-19-2005, 03:37

Originally posted by TurboDiverArt:
</font><blockquote>quote:</font><hr />Originally posted by JEFF'S TOW TRUCK:
[b] I know they look good but helping get gas miles :confused: I would think is a stretch.
Gm ones do come any color as long as it is black. :D I painted mine. Sort of my thought. I figure if it costs us $30 to buy one direct from GM and the aftermarket sells them for $15, what does it cost GM? Even with assembly labor and paint, it can

TurboDiverArt

09-19-2005, 05:05

Originally posted by jbell:
I might be the guy referenced getting 1.5mpg better. I have recored mpg averaged over several thousand miles. However my air dam is lower than the factory 4". I have mine extending down a little over 6"

The simple answer is that you pay a bigger mpg penalty on the aerodynamics of the rear of the vehicle vs. the front, as well as all of the turbulence at the bottom of the vehicle. It takes less hp to push more air out of the way with a big front air dam, than pay the turbulent air flow drag underneath.

Aerodynamics is THE biggest penalty above 45mph. As I run 75 all the time on my commute, aero is my enemy.

Now if you want something interesting (which I haven't done yet) is to get some airtab.com vortex generators, and put them on the back of a surburban. Tractor trailer, and RV owners swear by them for wind stability and mpg reasons. Didn't know that, thanks! Would you think it safe to assume that if you were seeing such a dramatic increase in MPH with a 6" air dam that you would at least see

jbell

09-19-2005, 15:38

plywood isn't 'that' bad...... Give it a try!!!

http://www.christ-our-savior.com/web/Picture%20424a.JPG

(you can't see the fiberglass plate at the bottom of the air dam, that extends back through the skid plate mounting points to smoothly direct the air past the a-arms)

And those are big tires, and big tires spell bad mpg...

Marty Lau

09-19-2005, 16:01

Originally posted by James Springate:
Some guy over at the "Place" posted a 1.5 MPG increase with an air dam, although not specifically this air dam. Heck, if it got 1MPG it would be worth it! Mr Taillight has one on his site for $15. I think it was Mr Tailight I called to order.....$15 for part shipping $29.50 total $45 ouch when the Chevy Dealer has them no shipping for $36.

jdmetcalf57

09-19-2005, 16:02

I agree with cow racer about GM's motivation. Heck they get pretty excited about saving 10 cents. Look at what they advertise about there trucks. That is what sells them. Everybody wants MORE POWER!! and less cost. If a chevy was $3000 more than a comparable ford but got enough better mileage to pay for itself plus some over the life do you think it would sell better than the ford? Probably not. However the current high fuel prices may change this some. Although I don't think too many people that can afford to pay $50k for a pickup are to worried about fuel economy. Us rednecks at the bottom of the food chain have to be content with whatever used junk filters our way.

TurboDiverArt

09-20-2005, 01:18

Turbo Al

09-24-2005, 07:49

jdmetcalf57, I keep ALL my trucks/cars in good shape just so you rednecks can have something nice to drive ;)
BTW the 1993 PU and the 72 LeMans are aready spoken for -- my 3 year old boy says he will be driving them "real soon dad" :confused:

As for the air dam I can't even keep the "skirt" below the bloody bumper on -- been ripped off 4 times While Hunting so now it't broken body sits in the garage. redface.gif

Marty Lau

09-27-2005, 15:10

Originally posted by Turbo Al:

As for the air dam I can't even keep the "skirt" below the bloody bumper on -- been ripped off 4 times While Hunting so now it't broken body sits in the garage. redface.gif That's the one we been talking about, I just picked up my replacement from the Chevy Dealer, and I paid less than $30. I ripped mine off partially couple three times before until last hunting season I tore it off. So I be putting the new on one. :D

TurboDiverArt

09-29-2005, 01:48

Originally posted by jbell:
Now if you want something interesting (which I haven't done yet) is to get some airtab.com vortex generators, and put them on the back of a surburban. Tractor trailer, and RV owners swear by them for wind stability and mpg reasons. I agree, that would be interesting. Probably would cost $120 and could increase MPG by 1 MPG. Would pay for itself in a year not including cost of paint.

I've thought about making a filler panel to go between the end of the gas tank and the bumper. Not sure if there is turbulence created in this gap but would be easy to make and would not be seen.

I'm tempted to create a big front air damn for the truck to see the difference. I've made exhaust modifications and want to first get a good sense of what these changes bought me before solving other problems. I'm up to about 18 MPG with the 4x4 Suburban (3.73 gears).

On the front air dam. Is it better to have the air damn straight down and then tie back to the cross member (90-degree angle at bottom) for smooth transition or on a straight line angle (maybe 45-degrees) from the bottom of the bumper to the cross member?

Art.

nathan71

09-29-2005, 10:13

Art, I think it is www.mrtaillight.com (http://www.mrtaillight.com) I know the owner and have done business with them in person. I have gotten very good deals at their store (ie, no shipping costs).

autocrosser

09-29-2005, 10:21

The 96 2wd also had tow hooks at least the 2500 did. I don't know about the 1500 Z71 diesel.

TurboDiverArt

09-29-2005, 16:07

Originally posted by IUPAC:
Art, I think it is www.mrtaillight.com (http://www.mrtaillight.com) I know the owner and have done business with them in person. I have gotten very good deals at their store (ie, no shipping costs). Thanks for the link. Lots of good stuff there! Replacement door seals, I've been thinking of replacing them for a while just to tighten the doors up some.

Anyone know the height of the stock air dam? It looks to be about 4 inches.

Art.

bbudus

09-29-2005, 19:52

Jeff,

Where did you get your hood from?? I would love to put one on my truck, looks great!!! :cool:

Bbudus

JeffsTowTruck

10-01-2005, 01:26

http://www.goodmarkindustries.com/HomePage.html
You will have to see who sells them in your area. They are all steel and actually a certified GM replacement

jbell

10-02-2005, 18:37

You want the bottom of the air dam to be 'blunt' and abruptly change direction at the bottom. The purpose is to make air want to go to either side of the vehicle, not under. In fact a large percentage of air dam's angle slightly forward at the bottom, not back, just for this reason.

The air dam really needs to hang as low as the front a-arms, and the factory lip doesn't do that.

As a side benefit, an air dam creates a 'low pressure' zone under the vehicle, and just behind the front a-arms, that gets filled with air going through the radiator -- increasing cooling, and reducing fan requirements. A good benefit for any 6.2/6.5 owner.

TurboDiverArt

10-03-2005, 14:47

Thanks jbell,

Does the low-pressure condition created behind the air dam create a lack of airflow that is of concern for a PMD cooler mounted on the mud shield? Is there still enough movement to allows the cooler to be effective? What about an intercooler?

Art.

jbell

10-05-2005, 19:45

The low pressure area I referenced helps 'pull' air out of the engine bay. At highway speed, you should have overall more air flow through the engine bay, and lower under hood temps with an air dam vs. without. How that affects the airflow and temp in the exact spot where your pmd is, I don't know.