improving a "battleship"

[ajac]

Well with my truck there was no rear quarter panels, just like another cab chassis/ flatbed out there. So I was thinking that if i was getting 17 mpg (20 on highway) without any panels, i could hop it up with some fabbed panels.

all this was exposed along with diesel tank
http://s274.photobucket.com/albums/j...t=P1100032.jpg

first off a little prototyping in foam
http://s274.photobucket.com/albums/j...t=P1100042.jpg

then some 1/4 luan just have to blend it to the body tomorrow and paint
http://s274.photobucket.com/albums/j...t=P1100047.jpg

and here is the full view

* oh I also popped off the headache rack, must have removed at least 3 sq ft of frontal area

[GasSavers_Red]

Looks good. Wondering what would happen if you extented the panels to hub height or to the bottom of the rim then wrap it back to the frame?

Welcome to GS

[kamesama980]

or just see where it sits at max capacity and leave about an inch of clearance at that point.

[ajac]

HAHA , max capacity that is a good one. max capacity is about 3-4 ton on payload. but that wont be functional for me. because in upstate ny hills and pot holes would ripoff anything lower than 8 inches from the ground.

well besides that today before work i painted the panels flat black, all sides. it is looking pretty good i'll get a pic tomorrow, as well as fill the tank. and then we'll see if mileage improves.

*on the plus side cabin noise is down drastically, now it is a dull roar

[Big Dave]

Good start, ajac.

[kamesama980]

ah, good ol' new york...you could make it out of assembly line rubber like I've seen some guys make front air dams for trucks out of. that's stuffs pretty durable. only make the mottom foot or 2 out of it for cost reasons. I'm just throwing out ideas here

[ajac]

yeah is doesn't help that the ski resort i work at doesn't plow or at least have a paved lot. then all the back roads is is great fun when they aren't plowed i feel like i am going to burst something, everyday.

her she is
http://s274.photobucket.com/albums/j...30023small.jpg

how about this? keeping it all flat like a hinging tonneu cover set at a slant, that way it can still be used as a truck.
http://s274.photobucket.com/albums/j...tbacksmall.jpg

The question is will there be any gain to having a 16" over 96" (8') slope versus a 16" high flat box. Which would be similar in height to a normal bed witha tonneu cover

[GasSavers_mattW]

If you are making a fastback cover then you want to have it running from flush with the roof at an angle of 11 degrees to the back of the truck so you would drop about 18.5 inches (if my trig is right) across the 96 of the bed. If you look at the following diagram under the "A" column it shows the drag and lift produced my a fastback shape at different angles with the lowest drag at 11 degrees:

So there is a definite advantage to have sloping rather than horizontal because as long as the air stays attached (and it will at 11 degrees) you would be reducing the area of your wake which is what slows you down the most. It might also be good to have the last bit of the fastback curve back to the horizontal so that you aren't producing any lift. You could use plexyglass for a rear window in the cover if you are worried about viability.

[ajac]

I have been thinking about that. But since it is actually my moms spare truck that I am driving since my truck's motor blew due to lack of coolant by the origional owner. So I am only doing minor things. That she agrees to. The full tear drop wouldn't work with that truck, i would love to do it. The truck is used as a truck, it moves industrial machines from shop to shop.

Plus a sheet of polycarbonate 4' x 8' would run me $100. While I am trying to do what I can with little to no cost. I have $10 in spray paint only so far.

[Big Dave]

Question for mattW: Where did you get those curves? I?d need to peruse them more closely. Obviously one want to produce minimum lift (positive or negative) if drag minimization is desired as we do. I thought my 17 degree setup was good but if 11 degrees is better, maybe I better reconsider. This makes sense. These exotic solar-electric cars are of nearly flat slope. 11 degrees might well describe them.