Hi all from Kiwi in central Canada (pickup aero cap / topper - pictures)

[rumdog]

Had the chance today to drive to a job not in a hurry and not too loaded with tools. Mostly highway with 10% gravel road. I took the chance to measure fuel consumption... best yet - 12.07 l/100kms, or 19.5 mpg
thats doing 95 - 100 km/h and round 70km/h on the gravel. Obviously no trailer! Pretty happy, i know it would be even better at slower speeds. Out.

[deejaaa]

good mileage. i was getting about that before i quit driving mine.

[rumdog]

Hi team, quick update on the gmc... yes its still going, has about 610,000 on it now. I finally got my hands on some gas struts to lift the topper. Only 15 bucks each from princess auto - love that place. Finding the right place to install them was a challenge, but success! The struts hold the cap up nice and actually hold it down when closed. A video would explain best. No more clamps needed round town, but i will clamp it when on highway.
I reshaped the tail a few months back, cut the corners off and lifted the tail angle slightly. Looks better now. Says me anyways!

[aardvarcus]

I really like how it looks like you have the shell hinged from the inside support, that is clever. (I guess I never noticed it in the previous pictures.)

[rumdog]

Thanks aardvarkas, i did try to make it funtional as i use the bed almost daily, and its no fun sliding in there on your belly. I used gate hinges for the pivot, allowing it to pivot at the very top/front.
Looks like the strut geometry is good as i can do 110km/h without the cap lifting - no clamps. (Calm conditions only). One night i might even do some ABA testing on the highway. Just need a parter in crime to lift topper on/off

[rumdog]

I dig the photo feed so heres a couple pics of the aerocap in action... 40 sticks of 10m rebar on top, and a load of tree roots.

[freebeard]

That looks sufficiently stout.

[rumdog]

The only thing awkward to haul is the long stuff like rebar (20') and baseboard (14'), and this is the best ive come up with - without having a rack. Long ladders and lumber fit in the box.
The edges of the topper bug me a bit... would like to round them off... minimise the vortexs coming off those long sloping edges. Will have the shop soon, so anything is in the cards...
I would like to make one with slightly different style.
Merry xmas all,
Rumdog

[aerohead]

Originally Posted by rumdog

The only thing awkward to haul is the long stuff like rebar (20') and baseboard (14'), and this is the best ive come up with - without having a rack. Long ladders and lumber fit in the box.
The edges of the topper bug me a bit... would like to round them off... minimise the vortexs coming off those long sloping edges. Will have the shop soon, so anything is in the cards...
I would like to make one with slightly different style.
Merry xmas all,
Rumdog

Last Friday,I snagged a 2000 paper online,by Prof. Alberto Morelli of the Turin Polytechnic Institute,Italy.His paper was about continuing research on basic streamlined bodies.
He said that for the lowest drag,the rear must be cut off just like a loaf of bread,'Shape K'

And that the chop,when viewed from the rear,should be circular,or elliptical in shape in order for the 'ring vortex' to manifest,which in turn enables the 'fluid tail.'

No 'angles' in the shape can be present,or it won't work.
He shows a 'fluid tail' for a 1984 FIAT Tipo-3 concept car,with around Cd 0.179.The tail is just 'smoke.'

[freebeard]

"New information has come to light, man."

Looking forward to finding out what the 'ring vortex' is.