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Old 01-10-2013, 06:23 PM   #1 (permalink)
rdefayette
Diesel Trucker
 
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Join Date: Apr 2012
Location: Aspers, PA
Posts: 35

JD - '04 Dodge Ram 2500 QCLB 4x4 SLT
Last 3: 18.93 mpg (US)
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"Wedge" Cap for pick up trucks

The intent of this design was originally to help improve fuel mileage by utilizing a “wedge” type bed cover to eliminate/reduce laminar airflow separation that is normally associated with traditional tonneau bed covers and bed caps.
Originally, it was just going to be a non-removable “wedge” but after thinking about it, it did not take much to make it much more functional for a variety of uses.
The main frame, semi-removable (bolted to the truck bed), consists of 3"x3" steel angle that runs the length of the bed on both sides and across the front of the bed. These angles have four tie downs attached on both sides for fastening loads in the bed. If required for load retention, tie-downs will also work under the steel angle anywhere along the length of the bed. There is a front “hoop” fabricated from 2" x 6" rectangular steel, roughly conforming to the cab profile. The hoop uprights also have tie-downs attached in order to facilitate fastening down loads when the cap is removed. The top cross bar of the front “hoop” also extends beyond the uprights, roughly to the width of the truck bed, and has 6”x6” steel plates welded onto both ends, which have two ½” holes to accept ratchet straps for the retention of long loads with the “wedge” removed. Again, the rails and front hoop assembly is bolted to the bed and remain in place when the cap is removed.
The “wedge” frame is fabricated from 1" square steel (aluminum could be used to save weight) and is covered with .040" black anodized aluminum. The “wedge” is hinged at the top horizontal bar of the hoop and raised/supported with gas lift struts.
If you notice in the pictures with the white skid/load in the bed of the truck, I have also made two adjustable struts for the back/rear of the “wedge” in order to adjust the height of the cap when carrying taller loads. The cap is normally in the full closed position but these adjustable struts allow secure closure at various raised and locked positions (up to slightly above horizontal).
When closed and locked/pinned in the full closed position the “wedge” cannot be opened IF the truck has a locking tailgate (either factory or aftermarket). There is no need for lock-type hardware on the “wedge” itself.
The “wedge” itself weighs approx. 100#. The “wedge” is removed from the frame by taking out the hinge pins that attach it to the top of the front hoop and disengaging the gas lift struts. This takes less than 5 minutes and only requires two people.
Briefly this “wedge” can be used and has the benefits of a tonneau/bed cover with additional height, can be used in a like a conventional cap (but not weather tight) in a raised position or completely removed for oversize/long loads.
It is not weather tight as I have constructed it right now but would be weather tight with the addition of a front window and weather-strip around the “wedge” perimeter.
To satisfy D.O.T. requirements for a third/high mounted brake light I installed two brake light/turn signals in the trailing edge of the “wedge” that operate from the trailer light connector and can be unplugged when the “wedge” is not on the truck.

Yes, compromises were made for functionality. I could leave the "ears" off but I needed these to secure long loads with the "wedge" removed. I also didn't follow the contour of the cab again due to time restraints and ease of fabrication.

I also mounted a rear view camera under the right "ear" and one on top of the left "ear". These are wired into my 7" GPS through a SPDT switch in the overhead console, switch left view behind the truck and to the left, switch center GPS, switch right down and to the right of the truck. Only blind spot is directly behind the tailgate.

My original goal was met, with an improvement in fuel mileage of 1.4 MPG, in real numbers, so far.

For those concerned about weight, the framework could be fabricated from aluminum.

With some minor modifications to the bed rails, not making them full length-shorter in the front with a partial rail near the tailgate, this would probably work on a truck with the "Ram Box" option.

If interseted I can send a link to my dropbox folder with additional pictures.

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__________________
Bob,
Dodge Ram '04.5, 2500 HO, Auto, QCLB, 4x4, CAI, 4" turbo back, Smarty Jr, Airdog 100. So Far
Previous; Dodge Ram '03, 3500, QCLB, 4x4, Dually, RIP
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