B2000 truck cap or kamm?
 

I've got an old B2000 I recently picked up and wondered about making either a full aero cap, or a kammback extension off the cab. The B2000 has some nice trim pieces behind the door that can be removed and would facilitate solid mounting of a kamm-type attachment, but I wondered if it would be more worthwhile for the full aero treatment - has anyone done a kamm attachment off a pickup cab?

Truck in question with skirt template:

https://lh4.googleusercontent.com/-I...0/IMAG0455.jpg

Also with regards to aero cap dimensions and angles, my bed is 6'4" (76 inches) long and five feet wide - the cab measures 19 to 20 inches tall. I understand optimal angles are 12-15 degrees - would this slope make it to the tailgate, or will I have to have a vertical panel on the back of the cap?

You could build a frame like mine first. I made mine out of 1x2 wood at first to git some basic knowledge and dimensions. Moved on to 2x3 wood later. My bed rails were made with 2x4 that I cut to the proper angle after my first mockup...looks like you would have to either bolt through the top rails or use some clamps. :D

With the bed rails in place...you could experiment with a Kammback or a full cover...it would be up to yer budget and time. ;)

I've read up on yours and others. One of the things I'm thinking of is a tonnea cover stretched over a frame like I did on an old speedboat I once built. I think it'll get most of the aero cap benefits with better visibility.

KruitzKraft.com - Classic Outboard Boats

http://kruitzkraft.com/dragonfly/HPIM1778sm.jpg

http://kruitzkraft.com/dragonfly/boat2.jpg

With great skills, you could make it work, aero & beautiful at the same time.

...would like to see your idea and build log.

Someone on here did a small cab extension that was about 1/4 the bed length a while back and showed no results. The thinking was that a short extension may compromise the low pressure bubble that helps aid air flow over the bed. A flush tonneau bed cover will give the most bang for your buck but a full taper cap will give you the best results possible. Due to time constraints and security concerns, I ended up getting a standard fiberglass cap that is flush with the top of the cab all the way back with smooth windowless sides. I saw a minimal gain on the highway but the added weight makes the cap a wash for slower driving. I'm still happy with it because it allows me to lock the bed and the tinted back window makes it hard to see what's in the back. All depends on what you are going for.

I'm not planning on hauling much in the bed - it's just for getting the boat to the lake on the weekends (so much for economy) and for winter commuting here in town. I don't think I'll be doing a lot of interstate type driving so I'd only expected modest gains from aero enhancements, and want to keep cost of the mods low for a quicker return. Because it's slower in-town driving, I want to keep an eye on weight of the truck and any mods as that may be more of a factor, owing to more acceleration cycles.

Do you know if they tapered the extension?

'course I could just go hog wild, remove the bed and make a full boat tail... :-) hmmmm

SAE Paper # 881874
 

The above paper was published by a team at Texas Tech University who had done model and full scale wind tunnel testing on a Ford F-150 full-size bed pickup.
In lieu of a full-on aero-shell they found that a cab-wing extension combined with GM's patented 1/2-tonneau cover produced drag reduction within 2% of the aero-shell.
The truck still had basically full utility of the bed,although,of course,one wouldn't be able to secure anything nor protect it from the weather.
My friend John Gilkison did this to his Toyota pickup and it lived up to expectations.
Also,a blister,atop a 1/2-tonneau,which mimics only the back half of an aero-shell is good for an 8% mpg by itself,same as the wing/1/2-tonneau combo.
Only down side is rear visibility.

Interesting - I wondered about a bubble in a tonneau. I searched and can't seem to find the article - do you happen to have or know where a photo exists of the cab wing?

photo
 

I've never posted a photo of the blister.
It's another one of my crazy ideas that actually bore fruit.You won't find it on any search engine.
I'll see if I can find it and get Al to scan and Photo-Shop it for me so I can post it.
I don't think there are extant photos of the cab-wing either,unless Dr.Maxwell or Pat Nixon at Tech published.I don't remember if the Paper had a photo of it.I'll look.
They did shoot video of the full-scale testing at Lockheed's Marietta,Georgia wind tunnel.I have no idea if it ever got 'published' on the internet.
I'll try for tomorrow,see what I can dig up.