Truck Aero, Bed cover DIY tonneau?

[Chris D.]

got a bunch of fiberglass from a friend at a marine shop and the resin is just plain bondo products..

[ptg0]

Hey-
I have found that MY modification provides the biggest gains in fuel economy while providing the most versatile starage arrangement. These lightweight boxes can easily hold a full set of golf clubs in the forward compartments and objects as large as 5 gallon jerry cans in the rear compartments with room to spare. You leave your tailgate at home and recieve an increase of well over 15% in fuel economy. Now a lot of people are saying that leaving your tailgate off or down does nothing to improve vehicle aerodynamics and I agree. Installing my boxes in the back of your truck and leaving your gate off, DOES IMPROVE VEHICLE AERODYNAMICS AND IMPROVES YOUR FUEL ECONOMY.

[COMP]

Originally Posted by Chris D.

got a bunch of fiberglass from a friend at a marine shop and the resin is just plain bondo products..

looking for updates

[aerohead]

Originally Posted by ptg0

Hey-
I have found that MY modification provides the biggest gains in fuel economy while providing the most versatile starage arrangement. These lightweight boxes can easily hold a full set of golf clubs in the forward compartments and objects as large as 5 gallon jerry cans in the rear compartments with room to spare. You leave your tailgate at home and recieve an increase of well over 15% in fuel economy. Now a lot of people are saying that leaving your tailgate off or down does nothing to improve vehicle aerodynamics and I agree. Installing my boxes in the back of your truck and leaving your gate off, DOES IMPROVE VEHICLE AERODYNAMICS AND IMPROVES YOUR FUEL ECONOMY. www.Alateinc.com

"To know and not tell,makes cowards of men." Abraham Lincoln

[diesel_john]

welcome to the site ptg0. how does that kamm effect work? diesel

[ptg0]

Thanks for asking deisel. Dr. Kamm discovered that after wind tunnel testing different shapes, the shapes that were chopped off seemed to deliver lower Cd's. He determined that was occuring because the airflow over the body was allowed to take its most natural path of least resistance, which as we all know is what aerodynamics is all about. The path of least resistance. Shapes that had trunks for instance did not seem to be as efficient as those that were "chopped" off. That is why station wagon versions of sedans seem to have lower drag coefficients. (Cd) That is also why in Europe and occasionally here wagons are refered to as "Kamm Backs" (Vega of the 70's)
Now I am sure that we have all seen how short the lifespan of cloth tonnues
are. If you look at a truck with a soft tonnue, you will notice a large amount of vibration at the rear of the tonnue while at speed. That is because the
path of least resistance for airflow over the cab wants the air to hit the bed floor about 3'-0" before the tailgate. When you have a cloth tonnue, they
tend to have a steel rod in them that forces the tonnue up about 3'-0" before the rear of the vehicle in an attempt to prevent the vibration caused by the air taking its path of least resistance.

That is why I consider the tailgate to be a large contributor to the "frontal area" of the vehicle. Even though it is obviously not "IN FRONT" it IS in the
airflow over the vehicle. To design the aerodynamics around the "bubble of air" created by that disturbance is extremely short sighted. And only and IDIOT would call me a fool for making that statement. By the way, I figure the tailgate creates an additional 10 sq. ft. of DRAG.

My PATENTED "Aer-Lockers" take full advantage of the Kamm effect by smoothing out the airflow over the rear of the vehicle and allowing the airflow to take its "Path of least Resistance" That is why you do not see a substantial gain simply by lowereing the tailgate or removing it. The bed structure and wheelhouse design contribute a large amount of turbulence to the airflow over the rear of the vehicle. My boxes eliminate that. By the way, I have done extensive yarn studies to determine the airflow OVER the rear of the vehicle with EVERY design variance. MY BOXES WORK! And they work better that any tonnue cover. You see, tonnue manufacturers claim a 10% fuel economy increase. I contend that once again, they do not allow the air to take its path of least resistance, but my design does and that explains my substantially greater fuel economy gains.

[diesel_john]

easy Frank, let him get some traction (friction), before you start running the weight up the sled.


diesel (spelling)


ptg0
It looks like the bed sides are acting like stablizing fins.
Could you post some of your yarn pics, that would be cool.
What type of instrumentation do you use to measure mileage?

[diesel_john]

I knew Whoopsie Daisy, she was younger then.

[Chris D.]

I'll be diving back into the project towards the midle of next week,
I a mental block of what to do on top of making preperation for moving to Minnesota..

I need to find a decent deal on 4 camper shell clamps, everyone I bid on ebay sold for well over 30+ bucks and thats a rip in my opinion..

Anyone got any used camper shell clamps they wanna sell to help me along the way?

Thanks

*Chris

[aerohead]

I've taken an idea ripped-off from what I've observed in some of my boats.They took empty paper towel tubes,slit them in half longways,taped them together to create longer length,then glassed over them to create fiberglass c-channel bracing ribs used on the underside of panels.Its dirt simple,exceptionally strong when bonded to a flat panel.They didn't even take out the chipboard tubes! Love what you're doing! Happy glassing!