Go Back   EcoModder Forum > EcoModding > Aerodynamics
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 06-28-2014, 04:07 AM   #11 (permalink)
Drive less save more
 
ecomodded's Avatar
 
Join Date: Jul 2011
Location: Vancouver Island, Canada
Posts: 1,189

Dusty - '98 VOLKSWAGEN Beetle TDI
TEAM VW AUDI Group
90 day: 60.42 mpg (US)
Thanks: 134
Thanked 162 Times in 135 Posts
Quote:
Originally Posted by RobertSmalls View Post
Have a look at the streamlining template.



Thinking big is good, and you may want to think bigger. The distance from where the curved roofline begins to where it meets the ground (roughly the length of the boattail), is 1.78*D, where D is twice the height of the vehicle. In your case, that's 6.34m! That's obviously not going to happen.

But if you line up the template with the widest part of the TOP view of your minivan, you find that D is the width of your vehicle, 1.90m, and 1.78*D is 3.39m. That's still a little long, but 70% of that length (i.e. 2.37m) gives you almost as good of a result. See this thread for drag reduction estimates for shorter boat tails. Even a 50% chop, 1.69m, looks to be good for a very large reduction in Cd.

I like the way it looks, and you'd probably have the least thirsty seven-passenger vehicle on this site. Very cool, and I hope you do it.
`````````````````````````````````````````````````` ````````````




When I apply the template to my beetle the length I get for a 70% length kammback is a 2996mm long or 2.996 meters (9 '6") long


The 70% length is 2.0972 meters or 6'10" in length from about the drivers seat to the end of the kamm / boattail


My Beetle has close to 1 ft. of its width in its fender flares, If I measure the width of the cars sides , the hatch backs width is 1.397 meters or 4ft 7" from 1 side of the car across the hatch to the other side.


Using the width of the car as 1.75d:

the length I get is :

1.397 x 2 = 2.794 meters , minus 30% = 1.9558 meter or 6ft and 5 inches for the 70% length compromise.

I have just Measured my Car from the rear bumper to the location of roof camber and it comes out to a very close 6ft 8 inches , 3 inches off of the 70% compromise.

I could go even shorter , to the 50% compromise and have a easy time with it.. 1.397 meters or 4ft 7" long from roof camber point

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
My 98 Beetle Dimension

Length: 4,129 mm (162.6 in)
Width: 1,721 mm (67.8 in)
Height: 1,498 mm (59.0 in)
Wheelbase: 2,515 mm (99.0 in)
Curb weight: 1,230 kg (2,712 lb)



I have been thinking more on the rear hatch and a secondary rear hatch for access is seeming like the better / best way to go. It would allow me to have the Kammback securely mounted in the hatches current position and join more seamlessly with the roof filler insert.

I am now thinking having it hinged will be unnecessarily difficult , and may be problematic.

__________________
Save gas
Ride a Mtn bike for errands exercise entertainment and outright fun
__________________



  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 06-28-2014, 01:40 PM   #12 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 16,267
Thanks: 24,392
Thanked 7,360 Times in 4,760 Posts
some tails

















__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
Reply  Post New Thread




Similar Threads
Thread Thread Starter Forum Replies Last Post
Getting frustrated by lack of prior Aero modded Camry's pgmomni Aerodynamics 61 09-25-2010 11:19 AM
Commercial Aero Race Wheel covers (clear acrylic) cfg83 Aerodynamics 8 09-21-2010 12:09 AM
The Daq Civic aero project continues . . . slowly daqcivic Aerodynamics 34 02-09-2010 12:03 PM
CRV Cross Country Trip Aero - Temporary Aero Just for the Trip walteraxe Aerodynamics 26 01-05-2010 12:37 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com