Commercially produced aerodynamic pickup bed cap

[MechPal]

Mr. Bondo (Brett),

First off, allow me to say that I have been searching for ways to save cash, and found your most perplexing and dynamic design.


I know this is a LONNGGG time from when the posts first started, however, I urge you to submit this to the Pepsi Refresh Project. This may be both a great promotional tool, and definitely a way to win dev and production money.


Lt. David H. Young

[cons]

Hello, I'm thinking about doing a similar aerobed on my truck and am wondering what angle you've got on the taper. I've heard 10-12 degrees is the magic spot, what have you seen work/not work.

[MetroMPG]

Hi cons - the ideal angle varies depending on the truck (cab height, bed length).

10-12 is likely a safe bet if you're talking about a conventional pickup.

The key is a smooth transition to the ultimate angle, rather than an abrupt transition from horizontal (cab roof) to 10 or 12 degrees.

[cons]

Thanks, that'll be very helpful. Also, I'm wondering if it will be better to tuck the side panels in 10 degrees, and let all of this extend past the tailgate a foot or so for better airflow detachment at the end. Do you think that'll make much of a difference?

[bondo]

Welcome to ecomodder cons and best of luck with your project. Several people on this site have constructed some really nice aerocaps using a variety of materials.

MetroMpg is right on about the key being a smooth transition off of the roof of the cab into the ideal angle of the roof of the cap. Since to sides of an aerocap become smaller as it moves rearward, I don't know if angleing the sides will have much benefit.

Here is some video of the Aerolid showing the flow of attached air along it's surfaces. This is just one example to follow in determining the shape of your aerocap. Even though the sides are not angled in, the air remains attached, along the sides, almost to the rear corners.

http://www.youtube.com/watch?v=gENbiqRtAMM

Bondo

[bluetwo]

That was cool seeing your lid in action. Nice job!

[100MPGUS]

Originally Posted by bondo

Metrompg,

My name is Brett and...
I tried to gain funding through the government. Nothing! I emailed my Senator on the matter four times and got no response. I emailed him a fifth time asking where I might send a campaign contribution to? I got a response to that email in less that 24 hours!...


I am honored to be in the company of those who pursue fuel efficiency,

Brett Herndon
Little Rock, Arkansas

Well, not surprised, just disgusted. I am sure there is someone out there with the money do get your product to the market. You just have to keep looking.

[cons]

Hello, I added my top 2 months ago and saw a 5 mpg improvement on average. I angled it at 12 degrees and extended it past the tailgate 8 inches for better air cut-off. Apparently I can't post pictures of it though because I too new to this website to qualify for that. I average 33mpg on the 2004 Ford Ranger 2.2L 2WD. These have always been in less than ideal conditions (all mountain driving with loads), so I think if I go 55 mph on flat ground I could get a higher score.

[cons]

Working on my number of posts here so I can add pictures.
I made the top out of Polycarbonate (Lexan) over an aluminum framing.
I gorilla taped all the edges so it's a smooth transition, as opposed to the other aerobeds that have a gap between the canopy and the cab.
When I screwed the rear down, my mpg dropped, so I undid that.

[cons]

Also, I had leftover lexan that I immediately taped onto the wheel wells. I never independently tested it (I just couldn't resist putting it on!) I know I'll catch flak from the hyper-accurate posters here.
Anyhoo, the top is really solid, $250 for materials. Went up in 2 days, and is working very well. I can see through it when I'm driving so it's great for that. Also lightweight. One of the problems is on dusty roads, it gets inside easily. And I can't lock anything in the bed, which is plainly visible too.
Getting a lot of rubber-neckers checking it out.