How to measure the 0-100 Km/h in an Auto E60?
#21
Contributors
Join Date: Feb 2005
Location: Stourbridge, UK
Posts: 2,070
Likes: 0
Received 0 Likes
on
0 Posts
My Ride: 535D Sport Auto
![Default](https://5series.net/forums/images/icons/icon1.gif)
Originally Posted by m630' date='Sep 14 2005, 01:07 PM
[quote name='Evenflow545' date='Sep 14 2005, 12:53 PM']I know there are some rocket scientists on board.? ??
How fast would a 520i do 0-100 kph at terminal velocity?
How fast would a 520i do 0-100 kph at terminal velocity?
[snapback]170526[/snapback]
heres a good definition, anyone want to do the math
![Laughing](https://5series.net/forums/images/smilies/imported/laughing.gif)
"....it's really an approximate equation for terminal speed (I say speed because velocity describes both speed and direction).
The two dominant forces in free-falling through the atmosphere are drag and
gravity. (Atmospheric) Drag is due to what we call (skin or surface)
friction. Long story short, the typical formula for atmospheric drag is
D = (1/2)*C*A*p*(V^2)
D is the drag force, in Newtons (or pounds)
C is the coefficient of drag, or drag coefficient, which is unitless
C is often written as Cd where "d" is a subscript
A is the area of the body's surface over which the air is flowing
p is the density of the air, in kg/(m^3) or slugs per cubic foot
V is the speed of the air flow relative to the body which is experiencing
the drag
V is expressed in meters per second (m/s) or feet per second
The units for D is then ( kg/(m^3) * (m^2) * (m/s)^2 ) = kg*m/(s^2) =
Newtons
or ( slugs/(ft^3) * (ft^2) * (ft/s)^2 ) = slugs*ft/(s^2) = pounds
note: a slug is the imperial unit for mass, just like the kilogram (kg) is
the SI unit for mass
note: the density of air is not constant, it changes over time and
location. You can read more about this in the references, below.
The force exerted by gravity is called weight. The formula is
W = m*g
W is the weight, in Newtons (or pounds)
m is the mass of the object, in kg (or slugs)
g is the acceleration due to gravity, in m/(s^2) (or ft/(s^2))
note: I'm using the carat "^" for exponentiation. a^b is "a" raised to the
power of "b", so that 2^2 is 4, 4^2 is 16
note: acceleration due to gravity changes with location. This is often
ignored for problems like what you're describing, but if you double your
distance from the center of Earth, then the acceleration due to gravity is
one-fourth what you felt before.
If there were no atmosphere to slow you down, the force of gravity would
continually accelerate you until you collide with something solid (like the
earth). However, the atmosphere does exists and it retards your motion
with the force of drag. Therefore, the resultant force you feel towards
the earth is weight minus drag (W-D) and when your speed increases to the
point that the drag you feel equals your weight, you will accelerate no
more. This then, is your terminal speed. And the equation to find it is:
W = D
m*g = (1/2)*C*A*p*(V^2)
and we can rearrange this with some algebraic manipulation to get
V^2 = 2*m*g/(C*A*p)
or
V = ( 2*m*g/(C*A*p) )^(1/2)"
![Stuart](https://5series.net/forums/images/smilies/imported/stuart.gif)
[snapback]170528[/snapback]
[/quote]And I always thought you used algebra to reduce excitment whilst on the job.
![Laughing](https://5series.net/forums/images/smilies/imported/laughing.gif)
#22
Contributors
Join Date: Aug 2005
Location: Austin TX
Posts: 6,554
Likes: 0
Received 0 Likes
on
0 Posts
My Ride: 2014 X5 xDrive 5.0 M Package Carbon Black Metallic/2008 M Roadster Imola Red
![Default](https://5series.net/forums/images/icons/icon1.gif)
Originally Posted by Evenflow545' date='Sep 14 2005, 04:10 PM
Exactly, M630.? I've crunched your figures, and it appears that a 520i will do 0-100kph in exactly 10.7 seconds while plummeting off a cliff.
Shebs, it's safer to keep doing neutral drops.? ? And, if I'm ever cruising around in my rig out in Cairo and stumble along on your transmission, I'll gladly return it.
Shebs, it's safer to keep doing neutral drops.? ? And, if I'm ever cruising around in my rig out in Cairo and stumble along on your transmission, I'll gladly return it.
[snapback]170603[/snapback]
#23
Senior Members
Join Date: May 2005
Location: Bucharest, Romania
Posts: 6,458
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://5series.net/forums/images/icons/icon1.gif)
Originally Posted by donv' date='Sep 14 2005, 04:57 PM
[quote name='Evenflow545' date='Sep 14 2005, 04:10 PM']Exactly, M630.?? I've crunched your figures, and it appears that a 520i will do 0-100kph in exactly 10.7 seconds while plummeting off a cliff.
Shebs, it's safer to keep doing neutral drops.? ? And, if I'm ever cruising around in my rig out in Cairo and stumble along on your transmission, I'll gladly return it.
Shebs, it's safer to keep doing neutral drops.? ? And, if I'm ever cruising around in my rig out in Cairo and stumble along on your transmission, I'll gladly return it.
[snapback]170603[/snapback]
[snapback]170636[/snapback]
[/quote]So? It doesn't mean it's not fun...remember weight has a word to say and on twisties it means quick times and lots of fun AND it's still a bmw...an e60 if i'm not mistaken
![Wink](https://5series.net/forums/images/smilies/imported/wink.gif)
#24
Contributors
Join Date: Nov 2004
Location: NYC & LI
Posts: 2,460
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://5series.net/forums/images/icons/icon1.gif)
Originally Posted by Evenflow545' date='Sep 14 2005, 04:10 PM
Exactly, M630.? I've crunched your figures, and it appears that a 520i will do 0-100kph in exactly 10.7 seconds while plummeting off a cliff.
Shebs, it's safer to keep doing neutral drops.? ? And, if I'm ever cruising around in my rig out in Cairo and stumble along on your transmission, I'll gladly return it.
Shebs, it's safer to keep doing neutral drops.? ? And, if I'm ever cruising around in my rig out in Cairo and stumble along on your transmission, I'll gladly return it.
[snapback]170603[/snapback]
![Laughing](https://5series.net/forums/images/smilies/imported/laughing.gif)
![Big Grin](https://5series.net/forums/images/smilies/imported/biggrin.gif)
![Devil](https://5series.net/forums/images/smilies/imported/devil.gif)
#25
Contributors
Join Date: Aug 2005
Location: Austin TX
Posts: 6,554
Likes: 0
Received 0 Likes
on
0 Posts
My Ride: 2014 X5 xDrive 5.0 M Package Carbon Black Metallic/2008 M Roadster Imola Red
![Default](https://5series.net/forums/images/icons/icon1.gif)
Originally Posted by BetterMakeWay' date='Sep 14 2005, 05:36 PM
[quote name='donv' date='Sep 14 2005, 04:57 PM'][quote name='Evenflow545' date='Sep 14 2005, 04:10 PM']Exactly, M630.? I've crunched your figures, and it appears that a 520i will do 0-100kph in exactly 10.7 seconds while plummeting off a cliff.
Shebs, it's safer to keep doing neutral drops.? ? And, if I'm ever cruising around in my rig out in Cairo and stumble along on your transmission, I'll gladly return it.
Shebs, it's safer to keep doing neutral drops.? ? And, if I'm ever cruising around in my rig out in Cairo and stumble along on your transmission, I'll gladly return it.
[snapback]170603[/snapback]
[snapback]170636[/snapback]
[/quote]So? It doesn't mean it's not fun...remember weight has a word to say and on twisties it means quick times and lots of fun AND it's still a bmw...an e60 if i'm not mistaken
![Wink](https://5series.net/forums/images/smilies/imported/wink.gif)
[snapback]170656[/snapback]
[/quote]Yes, it must be very light if it can't beat a sky diver to 120 MPH. ~(;^) And, you are right it still is a great car no matter how fast it gets to 62 MPH.
#26
Senior Members
Thread Starter
Join Date: Aug 2005
Location: Cairo, Egypt
Posts: 347
Likes: 0
Received 0 Likes
on
0 Posts
My Ride: 523iA, 2006, Silver Grey, Black Leatherette Interior, Fine-Wood Trim Poplar Grain Brown High-Gloss, 6 Speed Automatic Transmission with Steptronic, Automatic Air Conditioning with Extended Content, Interior and Exterior Mirrors with Automatic Anti-Dazzle Function (Incl. Folding Function for Exterior Mirror), Electric Front Seats with Memory for Driver, Multi-Function Steering Wheel with Cruise Control, Adjustable Steering Column, BMW Radio with 8 Speakers and CD Drive, Park Distance Control, Universal Bluetooth Cell Phone, Electric Rear Sunblind
![Default](https://5series.net/forums/images/icons/icon1.gif)
Originally Posted by Evenflow545' date='Sep 15 2005, 12:10 AM
Exactly, M630.?? I've crunched your figures, and it appears that a 520i will do 0-100kph in exactly 10.7 seconds while plummeting off a cliff.
![Thumbsup](https://5series.net/forums/images/smilies/imported/thumbsup.gif)
I did expect people like you making fun of my 520i, but it's ok. I like the car, it is fun to drive. Also, I will be glad to overtake you on any curve due to the the lower weight in front and the better front to rear weight distribution in my car
![Cool](https://5series.net/forums/images/smilies/cool.gif)
And by the way, due to customs and tax issues in Egypt, my 520i costs more than your 545i (my car costs exactly $81,000), so please give me a break.
Originally Posted by Evenflow545' date='Sep 15 2005, 12:10 AM
Shebs, it's safer to keep doing neutral drops.? ? And, if I'm ever cruising around in my rig out in Cairo and stumble along on your transmission, I'll gladly return it.
[snapback]170603[/snapback]
![Whistling](https://5series.net/forums/images/smilies/imported/whistling.gif)
It seems that due to your immense knowledge about the world, you've confused Egypt with other Middle East countries, oil is not the major contributor to the Egyptian economy due to it's scarcity. So you will never visit a rig in Egypt, especially around Cairo as you stated
![Wink](https://5series.net/forums/images/smilies/imported/wink.gif)
#27
Members
Join Date: Jun 2005
Location: France
Posts: 57
Likes: 0
Received 0 Likes
on
0 Posts
My Ride: 535d
![Default](https://5series.net/forums/images/icons/icon1.gif)
Just a comment on this thread : how do you measure the time?
I suppose that the best way to obtain a good time is to use a kind of automatic chronometer that stops exactly at 100km/h.
If the time data you provide are realised "manually", meaning you press start and stop, then I suppose you should take into account a human error coefficient (you cannot get as my opinion an accuracy of data of 0.1s when looking at the road and the tachymeter alternatively because this action costs you much more time) and also the neural transmission delay supposing that you have overcome the first problem in any (unknown) way.
Thias said, I suppose you were maybe to pessimistic and in fact your car is maybe having the announced measurements! The best solution is, for me, to forget about this and just have fun with your car when you press the gaz and be pressed against the seat!
I suppose that the best way to obtain a good time is to use a kind of automatic chronometer that stops exactly at 100km/h.
If the time data you provide are realised "manually", meaning you press start and stop, then I suppose you should take into account a human error coefficient (you cannot get as my opinion an accuracy of data of 0.1s when looking at the road and the tachymeter alternatively because this action costs you much more time) and also the neural transmission delay supposing that you have overcome the first problem in any (unknown) way.
Thias said, I suppose you were maybe to pessimistic and in fact your car is maybe having the announced measurements! The best solution is, for me, to forget about this and just have fun with your car when you press the gaz and be pressed against the seat!
#28
Contributors
Join Date: Nov 2004
Location: NYC & LI
Posts: 2,460
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://5series.net/forums/images/icons/icon1.gif)
Originally Posted by Shebs' date='Sep 15 2005, 01:15 AM
[quote name='Evenflow545' date='Sep 15 2005, 12:10 AM']Exactly, M630.?? I've crunched your figures, and it appears that a 520i will do 0-100kph in exactly 10.7 seconds while plummeting off a cliff.
![Thumbsup](https://5series.net/forums/images/smilies/imported/thumbsup.gif)
I did expect people like you making fun of my 520i, but it's ok. I like the car, it is fun to drive. Also, I will be glad to overtake you on any curve due to the the lower weight in front and the better front to rear weight distribution in my car
![Cool](https://5series.net/forums/images/smilies/cool.gif)
And by the way, due to customs and tax issues in Egypt, my 520i costs more than your 545i (my car costs exactly $81,000), so please give me a break.
[snapback]170805[/snapback]
[/quote]..now now now Shebs, please dont take offense, we were only joking
![Laughing](https://5series.net/forums/images/smilies/imported/laughing.gif)
![Thumbsup](https://5series.net/forums/images/smilies/imported/thumbsup.gif)
#29
Contributors
Join Date: May 2004
Location: CYPRUS
Posts: 136
Likes: 0
Received 0 Likes
on
0 Posts
My Ride: DMS 535d. Titanium Silver on Black leather. M- Sport Package.
![Default](https://5series.net/forums/images/icons/icon1.gif)
And by the way, due to customs and tax issues in Egypt, my 520i costs more than your 545i (my car costs exactly $81,000), so please give me a break.
Mine cost $91,000
here in Cyprus (total rip off) but still a great car to drive!!!!
Mine cost $91,000
![Devil](https://5series.net/forums/images/smilies/imported/devil.gif)
![Thumbsup](https://5series.net/forums/images/smilies/imported/thumbsup.gif)
#30
Senior Members
Thread Starter
Join Date: Aug 2005
Location: Cairo, Egypt
Posts: 347
Likes: 0
Received 0 Likes
on
0 Posts
My Ride: 523iA, 2006, Silver Grey, Black Leatherette Interior, Fine-Wood Trim Poplar Grain Brown High-Gloss, 6 Speed Automatic Transmission with Steptronic, Automatic Air Conditioning with Extended Content, Interior and Exterior Mirrors with Automatic Anti-Dazzle Function (Incl. Folding Function for Exterior Mirror), Electric Front Seats with Memory for Driver, Multi-Function Steering Wheel with Cruise Control, Adjustable Steering Column, BMW Radio with 8 Speakers and CD Drive, Park Distance Control, Universal Bluetooth Cell Phone, Electric Rear Sunblind
![Default](https://5series.net/forums/images/icons/icon1.gif)
Originally Posted by KYRIACOS' date='Sep 15 2005, 09:51 PM
And by the way, due to customs and tax issues in Egypt, my 520i costs more than your 545i (my car costs exactly $81,000), so please give me a break.
Mine cost $91,000?
here in Cyprus (total rip off) but still a great car to drive!!!! ![Thumbsup](https://5series.net/forums/images/smilies/imported/thumbsup.gif)
Mine cost $91,000?
![Devil](https://5series.net/forums/images/smilies/imported/devil.gif)
![Thumbsup](https://5series.net/forums/images/smilies/imported/thumbsup.gif)
[snapback]170995[/snapback]
![Laughing](https://5series.net/forums/images/smilies/imported/laughing.gif)
![Bashwall](https://5series.net/forums/images/smilies/imported/bashwall.gif)