Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Best Taper for Boattail on Shortbus Camper

stcyrwm · 10-11-2019, 01:57 PM

In the next week I am planning on building a boattail on my 2004 GMC Savana 3500 Shortbus Camper. I am looking at doing something in the 2 to 4 foot range for length. I would like to keep it on the shorter side but could be swayed based on fuel savings. At the moment I am leaning toward a compromise of 3 feet or so.

I am currently getting 11.25 mpg. The engine is the Vortec 6L Short Block V8. Overall length of rig is 20'.

I guess my main question has to do with whether there is an ideal taper for roof, sides and base? My memory from reading through a lot here in the past is that maybe 10 or 12% would be ideal but I wanted to double check that number.

All other factors being equal I would lean toward a smaller taper for storage space reasons but that is definitely secondary to potential fuel savings.

Any help here would be greatly appreciated!

Thanks,
Bill

PS
I did read the "Aero RV (custom boat tail for '95 Ford E-350 Class C motorhome)" thread and noted that several folks thought his taper was too aggressive but I couldn't find what would have been better % taper in that thread.

10-11-2019, 01:57 PM	#1 (permalink)
stcyrwm EcoModding Lurker Join Date: Jun 2018 Location: Montpelier VT Posts: 26 Thanks: 20 Thanked 7 Times in 6 Posts	Best Taper for Boattail on Shortbus Camper In the next week I am planning on building a boattail on my 2004 GMC Savana 3500 Shortbus Camper. I am looking at doing something in the 2 to 4 foot range for length. I would like to keep it on the shorter side but could be swayed based on fuel savings. At the moment I am leaning toward a compromise of 3 feet or so. I am currently getting 11.25 mpg. The engine is the Vortec 6L Short Block V8. Overall length of rig is 20'. I guess my main question has to do with whether there is an ideal taper for roof, sides and base? My memory from reading through a lot here in the past is that maybe 10 or 12% would be ideal but I wanted to double check that number. All other factors being equal I would lean toward a smaller taper for storage space reasons but that is definitely secondary to potential fuel savings. Any help here would be greatly appreciated! Thanks, Bill PS I did read the "Aero RV (custom boat tail for '95 Ford E-350 Class C motorhome)" thread and noted that several folks thought his taper was too aggressive but I couldn't find what would have been better % taper in that thread.