Truck Aero, Bed cover DIY tonneau?

[Chris D.]

Heres my perposed mockup..

I have also been thinking of making this so it bows upward a bit against the cab..

what do you think of this?
I could still make it hinge in the middle, mite be a fun challenge

[MetroMPG]

Originally Posted by Chris D.

I'm itchin to get my FE up because I cant seem to break away from 29.5mpg lately..

The fastest way to make the biggest gain in highway MPG on your truck is an aero shell like Phil's (aerohead's) or Brett's (bondo's). A tonneau will help, but probably offer a fraction of the benefits of the full, proper aerodynamic shape.

And as Brett has shown, it doesn't have to hinder access to the bed, when needed.

But I don't want to discourage you: if the full aeroshell is not in the cards financially, then by all means start with the custom budget tonneau! I have a feeling you'll be thinking more and more about the full aeroshell before the end of the summer

[Chris D.]

I've been looking and looking for a cheap fiberglass campershell
to hack up to make one, but i wont pay more than 150 for one..

I've been all over craigslist and the papers..

I'd definatly make an areo shell in a heartbeat..

[8307c4]

It does help, I'd say about +10%!
Mine cost me about $100 but it took some doing...
My first issues were weight and bed access, only a made-for-p'up truck cover would help relieve these issues. Even if costlier it's ready made, or so I thought.

Then the biggest two things are one water pooling or puddling when it rains...
It's not so bad until you got a 5 gallon puddle in the center of that thing

And aerodynamic down force behind the cab.
You see, as you drive there is a STRONG down force of wind in the rear.
I was amazed, so be prepared to play but a few hours and some materials gtg (I didn't have to pay for the plexiglass thou), the only other option is a decent cover cost like 4-5-600....

I heard you don't want to spend that much (neither did I) but know that a ready-made $200 cover will not do it, not by itself. At least that's what I learned.

You could, however, try some this ready-to-go cheapness:
http://www.jcwhitney.com/Soft-Tonnea...Ns=p_MIN_PRICE
(First one 65 bucks or so)
Not sure how it will act once you start driving, it also might require reinforcement...
As for it getting rained in, first wait and see...
Then maybe drill a tiny hole in center, pin hole?
But I can not say if this will compromise the material now...
This would have been my cover of choice except I have a toolbox.

So I ordered my Tarpeez from here (but keep reading):
http://www.supertruckusa.com/product...z&submit=Go%21
And this is the OEM's site:
http://www.tarpeez.com/

Unfortunately the OEM pictures do an injustice, once you go driving the wind pulls that cover right down to almost bed level so I had to reinforce mine from below (it does fine now).

The pics and a bit better description are towards the bottom of this:
http://ecomodder.com/forum/showthread.php?t=1109

Other notes:
The DOWN force is strongest near the tailgate, almost non-existent near the cab.
Well, at least on mine it was (club cab).

[Chris D.]

I started building it yesterday..

heres what I did..

Heres my start..

Heres what the sheet of 1/8" panel I'm using..


mockup to get the spacing just right..



One half of the top cut and trial fitted just to see how it'll work..



I got my measurments and got the 2x1's cut... Today all I did was get the frame cut, predrilled and screwed together. I'll glue these together later..
I pre drilled everything and used fine threaded drywall screws (what I had)


the two frames are built, just sat in place.




Now the hinge part...

If I do them like this, I can swing it open and it'll stay open at an angle..


heres how the open position would look


But I'm concerned about stregnth and if the wind hits it and messes it up..

But if I flip the hinge so its sandwhiched between the 2x1's,
it'll flip completly over onto itself and lay flat when opened..


now picture that right frame attached to the right side of the hinge, now open it.. this shows it far more open than it would be if it was attached tho..


I like the hinge on top and it would be easy to make it look flush and clean.
but at the same time I dont like that cover being able to just hang like that..

And the other way with the hinge sandwhiched between the panels being able to swing open and touch the other panel flat the hinge spine sticks out a little.

blah..

I'll figure it out, shoot some ideas if ya got em, im sure theres some sort of hinge out that would would work killer for this, just haven't seen it or know about it yet..



Todays progress...

Screwed and glued..

I added 1 additional center brace per panel for a little extra stregnth..


I sat it into position and taped it in place so that the adhesive would dry and the frames stay true..





Once I add the upper panels and glue those in place and get em with finish nails,
I'll fiberglass it with about 3-4 layers on top, then let that setup..

Then I'll flip it over and route down those underframes to shed weight and lay a few layers of glass over that and we should be solid..

About the only thing I need to figure out is how to seal
up the crack in the hinge section to keep water/dirt out..

[Chris D.]

frames are all dry and pretty darn solid!

ok, I couldn't leave crap alone..
just before Easter dinner I was the guy in the neighborhood making all sorts of noise

heres the metal lips that will also support the outter edge of the wood to be fiberglassed around.. This is why I recessed the wood slightly to make up for the thickness of the L brackets..

I had this all worked out in my head before I bought the brackets..
so far I've gotten extremly lucky with everything and taking it slow..









This should make a little more sence now..
yes, they'll get a trim



yes, they will be trimmed

[AndrewJ]

Originally Posted by Chris D.

I've also wondered if adding a slight lip off the back of a flat bed cover helps or hurts aero?
like this..

The way I see it the lip is only going to help FE on a (very) short bed, or with an abnormally tall cab. The lip would help improve the angle between the top of the cab to the top of the tailgate. Ideally that angle will be between 12-13 degrees. That angle is the steepest angle at which airflow will remain attached at highway speeds. Obviously, there's no bodywork for the air to attach to behind your cab, but the angle is still important, because the stagnant air trapped between the cab and bed will still have to conform to that angle.

So here we have a stock (current gen) Taco. And you'll notice that the angle between the top of the cab to the top of the tailgate is already 12.5 degrees, quite the optimal angle already. No need for alteration there!




So here's a hypothetical short bed Taco (don't know if they actually have beds this short.) The angle has changed from 12.5 degrees to 14.3 degrees, too steep for airflow to remain "attached."
Now, adding a little lip to the top of the tailgate will help to get that angle back to 12.5 degrees.




This is the same sort of idea that's behind the decklid extensions on Bonneville top-speed racers.

[Chris D.]

Last of the day progress..

Liquid nails FTW!!!!


Then I used a peunmatic finish nailer to get things down good and tight..
Now that its solid, I sealed everything up with the excess liquid nails and smoothed it out...



I added some weight to let it setup for a few hours..




after that I checked everything out.. so good so far





Tomorrow I'll tackel the back half... then its fiberglass time

[MetroMPG]

Nice progress. Watching with interest.

[Chris D.]

man, I'm a dumbass...

I had the larger panel just sitting on the back of the truck and thought I'd just drive
down the street to home depot because its only a block away and a 30mph zone tops..

at exactly 12mph, the fukker flew off like a styrofoam cup LOL

No real damage but man.. its a dead calm day and I was just cruizing..
No speed bumps or anything..
it mared up one section where it still needs to be trimmed anyways.. (top edge)
So no biggie.. I'm just glad nobody was behind me..

I wasn't using my head on this one..

Just shows ya how super light is it so far!
check it..