Belly pan for trucks
 

How do you deal with air flow under a truck? No matter how you smooth the air out from the front to the rear axle you still have the rear axle in the way. Do you deflect air out from under the truck with trailer skirts?

Truck underbelly
 

First you turn the truck over........:D:D:D:D:D

With a solid rear axle, I would build the underbelly rearward to the axle, leave space for the suspension travel & axle then start behind the axle and continue to the bumper.
That's my starting point and I'm stickin' to it. :):)

I just got mine done today...

My belly pan thread over at ToyotaNation.com... ;)

I lowered my belly pan about 4½" below the frame so it's pretty close to the bottom of the rear differential.

This is what it looks like from the front going to the back... :D
http://i164.photobucket.com/albums/u...0/IMG_7507.jpg

From the back going to the front...
http://i164.photobucket.com/albums/u...0/IMG_7524.jpg

I just got my second best ever gas mileage with a 26.58 mpg at 65mph. Previous run last year fer the same time period and same drive was 20.49 at 70mph. :D

looks pretty good bamzipow, but might I make a suggestion and overlap the panels from the rear to the front so there is no chance of an edge flapping and parachuting.

They actually butt up against each other and I've taped some seams down. Thanks fer the suggestion. ;)

The engine bay panel still needs to be revamped since I put in the cross members. It's short about 2½"... :(

at least you have a bellypan, Im still trying to find materials to make one for my ranger, along with how Im going to go about it in the first place.
unfortunately, there wasnt many (if any) coroplast signs around me during the elections, so I could grab any up. but even then, Im not real comfortable using that type of material, so I think Im just going to stick with my original plan of using lightweight aluminum.

I initially used 1x2 wood and luan to build a test belly pan before I moved on to my current choice of materials. I wanted to learn what was going to be my best method to approach my goals fer my belly pan. One of them was fer minimal fasteners to be removed fer access. Another was adjustability...I can raise or lower the belly pan with some PVC pipe and longer/shorter bolts. :D

I would say give some thoughts to some "test" materials before you move on to sheets of aluminum. You don't want to find out yer design wasn't optimal fer yer material choice... ;)

good point
I think I will see if I can hit a recycle center and see if they have some coro.

That does look great bamzippow, do you have your own thread about building it here?