[gumby79]

The success of the 1/2 tanto has led to the fat tail gate and duck but shape at the top of the gate. I noticed this after building myAero Tonto . And more recently seen explanations of what the aero designers were thinking, wind tunnel smoke show of the effect done by ford. The fat gate gave the air a place to reattach brief but enough to shrink the size of the hole in the back of the donut .you tube ford pick up . They widened and extended the 3rd brake light with a slight down angle to aim the air at this small patch of flat real estate. This is making it more difficult for toper/ tonneau cover manufacturers as the pice is no longer square ( curved doors are harder)and the flat space swings in a compound arc.

The pouch at the top of the gate is to turn the up draft(upper circulation bubble) to the rear sooner . Reducing the rooster tail effects protrusion above the tail gate. On my build the rooster tail is 100' behind the truck , with the exception of 2 strips from the tires. Then it fans out . An oddity is that the dust stays close to the ground(5-10') even at speeds of 70mph on dirt.
Apon closer inspection you'll notice that the back of the tonto extends 8" past the tail gate. Without interfering with tailgate use.
I was looking at garage door bottom seal as a flexable cab gap seal , but need some of that clear protective stuff the dealers install to prevent rust. Thies rubber seals slide into a bendable Al track. This was one of the findings, seal the cab to bed gap. The top edge is more important than the sides. Ford is using a labyrinth seal on the bed sides to alow movement without contact. This was also my finding at Darco tapeing my gap and cap gaps ( shrink wrap is under enough tension to Taco The Birdcage frame, as there is bias in the X Vs Y shrenk rate of this particular product that i didn't account for) -.037 Cd
The cap was good for -0.101Cd by it self. Air dam 5.5"in front of the tires and 3.5 in the center , was +0.017 ( bad). According to Darco + 12lbs of rear lift is generated @200mph with the cap. I had an incadent were I didn't latch the cap and drove miles till I finaly saw a car behind me in the center mirror.thinking to my self bright lights havent bothered me sence I put on the cap. "THE CAP. THE CAP IT IS OPEN " floting 10" off the tailgate. This was V1 25lbs this is how much air is travling up the back of the tail gate.

Boost at low Rpm aka cruse freeway.
For low rpm boost you need a small exhaust houaing or over fueling you can guess witch one we vote for. Small turbo. When in direct drive on the freeway /towing this will increase EGT and over speed /boost the turbo. So in order to get the best of both worlds the manufacturers have gone to VGT turbines Ive seen theas set up with a spring gate , just put a stop to prevent the spring from closing to far. The other alternative is aDiverter valve. This works by diverting all exhaust through 1 passage increcing the velocity of the exhaust stream giving it more Force against the wheel. This happens till the preset of 20psi(adjustable) were it opens both to sides progressively . Eg an hx 40 16cm becomds a n hx 40 8cm under 20psi. Im' thinking of using a With an additional adapter plate or T4 manifold this can be used on a T3 housing . Were as on a ford Im not fimilur with the up pipe set up, its doable.
Glad you are taking time to test a V1 V2 V2.1 if you can live with mirrors only as I do run the tonneau cover to just below the top of the cab. Slide it rear word( distance depends on your tail gate clearance and preference) add a sizeable gap filler to soffen the suddeness of the flat roof to 12° down. Your idea will work how well depends how far you are willing/can go.
An alternative to the 1/3 + wing is 1/3 + Bonneville spoiler -gurny flap. At both the cab and tail gate.