Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - 95 Dakota Extended Cab Aero-Topper

jviolet10 · 04-11-2017, 02:55 PM

Ok everyone, i have 4 weeks to build an areo topper for my new truck so here is my plan. Please feel free to comment with any input (supportive is preferred) and thanks for reading!

Current Situation:
Attached is a 2D sketch of my roughed desired topper shape and dimensions. The only incorrect information is the height because the previous owner replaced the stock wheels (215/75r15) with some newer dakota wheels (245/75r16). These will eventually be changed back to normal.

The truck currently averages about 17.5 mpg. Problem is, it falls on it's face over 65mph. I'm hoping aerodynamics will help with issue because I don't plan to drive any slower XD

Design Goal:
The 6.5ft bed is pretty short to work with but I should still be able to get some better aerodynamics with it. The bed must remain fully functional and able to contain itself. I'm not going to crazy with this due to fear someone will screw with my work if i leave it parted on the street in Denver. Rearward visibility will not be a problem since installing a full-time reward camera to watch behind me.

Plan of Attack:
Fiberglass. I hate working with it but it works well, it's strong and its relatively cheap. Plus my dad is an expert with it so I'll be letting him do all the heavy lifting!
I'll build the skeleton frame from treated lumber because I have a woodworking shop with all the necessary tools. From there I'll have to use some type of fencing-like material to mold the shape and design. Next I'll hang the topper vertically from a tree to pull the fabric tight and eliminate low spots before starting to apply epoxy and more layers. Once complete, I'll cut out the door on top what will fold down to allow full functionality of the bed.
Based on my 2D sketch, you can see the rough dimensions I'm working with and aiming towards. I'm cheating with a 3 degree initial angle and ending at 12.5 degrees with a decrease in height of 13".

If anyone sees a big red flag in my design of plan please let me know! Also, would there be any considerable gains by simply extending the cover to the length of the tailgate in the down position since the angle has already been reached?

04-11-2017, 02:55 PM	#1 (permalink)
jviolet10 EcoModding Lurker Join Date: Apr 2016 Location: Ohio Posts: 11 Eckie - '00 Toyota Echo 90 day: 41.94 mpg (US) 95 Dakota - 3.9 v6 automatic - '95 Dodge Dakota SLT extended cab 90 day: 21.07 mpg (US) Thanks: 0 Thanked 18 Times in 9 Posts	95 Dakota Extended Cab Aero-Topper Ok everyone, i have 4 weeks to build an areo topper for my new truck so here is my plan. Please feel free to comment with any input (supportive is preferred) and thanks for reading! Current Situation: Attached is a 2D sketch of my roughed desired topper shape and dimensions. The only incorrect information is the height because the previous owner replaced the stock wheels (215/75r15) with some newer dakota wheels (245/75r16). These will eventually be changed back to normal. The truck currently averages about 17.5 mpg. Problem is, it falls on it's face over 65mph. I'm hoping aerodynamics will help with issue because I don't plan to drive any slower XD Design Goal: The 6.5ft bed is pretty short to work with but I should still be able to get some better aerodynamics with it. The bed must remain fully functional and able to contain itself. I'm not going to crazy with this due to fear someone will screw with my work if i leave it parted on the street in Denver. Rearward visibility will not be a problem since installing a full-time reward camera to watch behind me. Plan of Attack: Fiberglass. I hate working with it but it works well, it's strong and its relatively cheap. Plus my dad is an expert with it so I'll be letting him do all the heavy lifting! I'll build the skeleton frame from treated lumber because I have a woodworking shop with all the necessary tools. From there I'll have to use some type of fencing-like material to mold the shape and design. Next I'll hang the topper vertically from a tree to pull the fabric tight and eliminate low spots before starting to apply epoxy and more layers. Once complete, I'll cut out the door on top what will fold down to allow full functionality of the bed. Based on my 2D sketch, you can see the rough dimensions I'm working with and aiming towards. I'm cheating with a 3 degree initial angle and ending at 12.5 degrees with a decrease in height of 13". If anyone sees a big red flag in my design of plan please let me know! Also, would there be any considerable gains by simply extending the cover to the length of the tailgate in the down position since the angle has already been reached? Attached Thumbnails Last edited by jviolet10; 04-11-2017 at 03:01 PM..