Hi all

I'm playing with the CAR_info.bin files feature of LFS. I already made successful works with suspension data contained in those files.
Now I'm working with aerodynamics and I found something interesting when I tried to get aero results matching LFS's ones:

What LFS says about aero forces for the FBM with default setup at 60m/s windspeed:

Rear wing:
Lift= -859 N, Drag= 202 N

Front wing:
Lift= -753 N, Drag= 122 N

Undertray:
Lift= -1440 N, Drag= 360 N

Body:
Lift= 0 N, Drag= 720 N

Total lift= -3052 N
Total drag= 1405 N

Now here are my results:

Rear wing:
Lift= -1673 N, Drag= 184 N

Front wing:
Lift= -1804 N, Drag= 165 N

Undertray:
Lift= -3456 N, Drag= 576 N

Body:
Lift= 0 N, Drag= 900 N

Total lift= -6932 N
Total drag= 1825 N

I'm quite puzzled with this, but the bin file format doc says:

Quote :

multiply by speed squared to get lift value

OK my values seem to be correctly calculated but so much difference...

Does someone already experienced this?
Did I made a mistake?
Is LFS wrong?

EDIT: yes I made a mistake

How can we tell if you made a mistake if you don't tell us what you did?

OK detailed procedure:

• In the garage screen, with FBM selected, default setup selected, press O key to generate a bin file
  
• With a home-made program, retrieve aero data from the bin file according to the documentation:
  Quote :

  // Now 4 aero blocks - rear wing, front wing,
  undertray, body : 20 bytes each)
  
  128 Position : x, y, z
  Lift : multiply by speed squared to get lift value
  Drag : multiply by speed squared to get drag value
  
  
  
• Then for each drag and lift value, multiply it with speed squared
  
• Speed is assumed to be in m/s and resulted values in Newton.
  

forget this thread, there was a problem in my program, my results are now correct and LFS rulez

Ah, you already got it... I just did the calculation myself and was about to show you how. Well glad you fixed it anyway.