View Single Post
Old 11-05-2016, 07:54 PM   #25 (permalink)
seifrob
Permanent Lurker
 
seifrob's Avatar
 
Join Date: May 2011
Location: Czechoslovakia (sort of), Europe
Posts: 348

Dáčenka - '10 Dacia / Renault Logan MCV 1.5 dCi (X90 k9k)
90 day: 47.08 mpg (US)
Thanks: 129
Thanked 198 Times in 92 Posts
Quote:
Originally Posted by BigChief View Post
... could you give me some insight into how you arrived at that?...
As I said, it was back-of the envelope calculation without any tools. So I had to estimate height, width, drag coefficient and weight. That envelope in question (alright, it is back of IKEA leaflet in fact) is attached. I hope someone wiser (aerohead, freebeard, kach22i??) will check it.

What I donīt know is drag coefficient of large diameter tube. Regardless of that, general solution (formula) is there, use your own numbers (in metric).

EDIT: I should explain: If a car flips or not is question of ?moment? - i donīt know correct term in english. When flipping, you have two levers. One is weight of your car acting on half of your wheelspan, pinning you to ground, the other is aerodynamic force acting on lever as long as half of height of your car (approximately). When aerodynamic force multiplied by the lever length is greater than weight multiplied by half of the width, you are in trouble.

It would be much easier to explain it i my native language. (but much harder for you to understand :-) )
Attached Thumbnails
Click image for larger version

Name:	IMG_9651_s.jpg
Views:	42
Size:	53.9 KB
ID:	20840  

Last edited by seifrob; 11-06-2016 at 08:39 AM..
  Reply With Quote