Building aero cap for dodge truck with ?'s - Fuel Economy, Hypermiling, EcoModding News and Forum

nubbzcummins · 05-28-2010, 02:50 PM

2006 dodge ram 2500 quad cab short bed. Framework is wood front and back that has 3/4" ID PVC running length wise with bed with maximal of around 8-10" between PVC pipes which will support plastic. Just wondering if 4 mil plastic should hold up to the wind/weather when going down the road if held snugly to framework? Sorry no pics.....

nubbzcummins · 05-28-2010, 10:36 PM

Finished this today and went for a test run. At 60mph on a flat stretch of road without the aerocap the truck was running 20-22% load on the motor per scan tool. With the aero cap under the same conditions the load went down to 17-19%. Does not seem like much until you do the math and find that is aprox 17% reduction in load on the motor meaning increased FE..... BTW...cap materials were free.....used scrap wood and found other stuff on the side of the road on my way home from work one day..... Also cap can be taken apart/put together in aprox 15 minutes.....

nubbzcummins · 05-30-2010, 07:49 PM

Here is a pic I took today of my very simple aero cap. This is not a final but one in the works for testing purposes. Let me know how and where I need to re shape it. I want to get the general shape as close as possible so I can eventually make it fiberglass..... Can someone do a teardrop overlay?.....

slowmover · 05-30-2010, 09:10 PM

Looking forward to more.

bondo · 05-30-2010, 09:15 PM

Looking good nubbz! One thing I can see in the picture you posted is that the roof of your lid has a bit too much of a hollow in it. You may even see better results if you can put a positive arc to the roof line of your lid.

Aeroheads template can be a good guage and most here seem to find a 12 degree or so slope to the roof is best. You have my respect for your efforts.

Have a good Memorial Day.

Bondo

nubbzcummins · 06-02-2010, 01:55 AM

Will be building a sturdy frame soon and gathering materials for fiberglassing. Plan for it to have some positive arc and be no more than 12 degree slope. Fiberglass will be approx 1/4"-3/8" thick with 3-4 layers with frame attached underneath for extra support. Will keep everyone posted.....

nubbzcummins · 06-06-2010, 06:12 PM

Did a short run(51 miles) with the simple aero cap in the pic and got 25.3 mpg! The final one will be better designed.....

bondo · 06-06-2010, 10:22 PM

Nice number nubbzcummins!

Looking forward to your new design and what an increase in fuel efficiency it will produce for you.

Bondo

nubbzcummins · 06-08-2010, 01:14 AM

This is version 2 which consists of a strong wooden frame covered with 4 mil plastic. Notice the positive roofline arc and looks to have a smoother flow to it. Will be testing soon.

bondo · 06-08-2010, 07:30 PM

Version 2 looking good. I see you did add more of a positive arc to the roof.

How far are you from Mooresville? That is where the A-2 wind tunel is at. Neat place to just visit. The rate for 1 hour of testing is very reasonable.

Looking forward to your new fuel figures.

Bondo