Would I see positive numbers with a belly pan on a stock height truck?
 

From what I see people have lowered and created belly pans.
I don't plan on lowering my truck, but am interested in doing a belly pan for numerous reasons.

Granted it wouldn't be equal gains, but would i see some sort of gains in fuel economy?

Yes. Phil (aerohead) has posted aerodynamic studies where OEM's have increased aero efficiency anywhere from 5%-15%, usually resulting in just a couple MPG.

http://ecomodder.com/forum/showthrea...-6-a-2670.html

You would have better luck with an aero topper (see the home page) that has been unofficially shown to improve gas mileage by 20%.

http://ecomodder.com/forum/showthrea...d-cap-583.html

Also look into an air dam made of lawn edging, or maybe an S10 Xtreme bumper/lip. This will push air to the sides, away from the turbulent under body.

But of course you already know that the most useful way to approach this is many small measures adding up, instead of putting all your hopes into one mod.

That's good to know, other than fuel economy it would be A LOT easier to clean the underside (if i go aluminum) and wouldn't have to worry about rust as much.

I planned on getting a retractable tonneau cover, for me it seems more practical than the topper.

All in due time though first is my ac compressor, then exhaust, then electric fan/new intake.

This will leave me enough time to plan how i'm going to go about this

Honestly, read BamZipPow's thread. I know Phil has a very nicely done Toyota as well, but don't know if he has a thread on it. After an election go to the campaign headquarters and ask if you can have some extra signs. The bigger, the better. They're made of coroplast and that will be extremely easy to make aero mods with. I installed a front belly pan on my Probe in an afternoon with nothing but coroplast, zip ties and a box cutter.

Aluminum wont rust but it will cause the steel its touching to rust like crazy, I have to break down my trailer and repair steel that is starting to rust heavily because its been in contact with aluminum plate for 3 years.

For a truck under body I plan to go with galvanized sheet steel or something nonmetalic like plastic or fiber glass.

Good thing its election year :D I could make it with that, then either leave it, or use it as a template if it go for some sort of metal.

how durable would the fiberglass be? or is it gonna be (as strong as you make it sort of thing) plus how would it hold up with the exhaust pipes being over it?

and whether i go with galvanized steel or aluminum, should i just put some sort of bushing all around? kind of like weatherstripping or something

The coroplast is remarkably durable in this application. If you worried about rocks and road debris coming up, remember it will simply give and pop back with most hits.
My truck is a rust bucket underneath. I can't wait to get my bellypan on.

Fiberglass can also be rigidized if you care to take the time and work. Get aluminum household screen and place that in between the layers of fiberglass. This creates a heck of a lot of weight though :( I would personally recommend, as others already have, to use coroplast. I took a bird to the coroplast on my bumper at 55 mph and aside from bird stuff, can\'t hardly tell where it hit.

galinized steel?????????

!. you need to look at underbelly pans that have been done on the site. use the search function.
2. there is absolutely no rational to using something as heave as steel.
3. this idea has neen beaten to death like a dead horse.

When your empty weight is 5,800lb not too worried about weight.
But I will likely use Coroplast - Manufacturer of Corrugated Plastic Sheets for most of it, I was thinking the 26ga sheet metal would be good for places close to the exhaust.