Truck undersides smoothing idea
 

I was looking at some of the best places to improve on my aerodynamics cheaply, and I found a couple places that note the space between the framerail and the body panels of a truck.

I have some foamboard available (2" X 8' X 4' X as many as i want) and was thinking of filling this big void.
Do you guys think this stuff is road worthy? I don't know how I would secure it up there. Any ideas on that?
Any other ideas to do with this foamboard?

You could make an aerocap out of that foam. I wouldn't place it on the underside of your truck, because of its flammability and nearness to the exhaust.

If you do a search for 'underbelly pans' there are probably 5-8 different completed vehicles that you could look at and get some really great ideas............

oh look, there's a link right in my signature box......

My T-100 truck under belly pan... ;)

I looked at your thread. Real nice. Do you have any problems with speed bumps in regard to your side skirts?

Only if the truck is loaded down and the speed bump is one of those new/tall ones. On steep driveways it will scrape when I'm high centered...but that's why I used Coroplast. ;)

I'm looking to move to the conveyor belt material. Just have to git motivated to buy some and have it shipped. ;)

This image gets posted somewhat regularly on here:
http://ecomodder.com/forum/member-ae...mendations.jpg

GMC Truck Division found three areas to tweak that netted a combined 2+mpg increase. So, I think filling this void is certainly a worthwhile endeavor.

I used corrugated plastic on a frame made of steel strapping (see thread in sig). I planned on covering the voids on the frame rails with the same construction, I just haven't gotten to it yet.

Has anyone thought about getting a plastic bed liner from the junk yard to make underbody, wheel spats, fairings ...

Yes, it's been done by ngrimm - possibly others as well.

http://ecomodder.com/forum/showthrea...pan-16781.html

This is my work in progress thread. So far I have the front 2/3 of the underbody covered as well as boxed in the front wheel wells. It has been a lot of work but the reasuls have been amazing! The drag reduction is like adding 20hp to my truck and actually spending less on gas at the same time.

http://ecomodder.com/forum/showthrea...ect-18230.html

Absolutely the picture I was thinking of.
I have a chin spoiler, I have a hard tonnau cover, and now I'm hopeing to redo the exhaust, and, while i'm under there, cover the side areas highlighted.

Will be redoing the exhaust at the same time on a lift. Really, if people think that Coroplast is non flammable and THAT's ok under there, then you're sadly mistaken. Now, if you do your research, it's probably MUCH less flammable than most other things, but the foam I'm refering to is actually a part flame retardant for building structures between block and bricks that we use on our construction sites. This is NOT your normal foam, it's slightly different, and it's actually 1 1/2" so it may not be ideal anyways.

I will probably wait until I get to a job where they are tearing out some ductwork or something to get the sheetmetal and use that perhaps.
I don't really have a cheap coroplast supply around here.