Quote:
Originally Posted by Weather Spotter
When you say 24%, are you saying my car fills 24% of the ideal shape (blue line) or that there is 24% not filled?
The Matrix has a Cd of .321 stock.
you peak my interest in the % possible improvement, I am willing to try a tail, but I am not sure exactly how I want to do it. Ideas?
thanks
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The 'Aerodynamic Streamlining Template' is set up where any vehicle image is scaled to fit it's point of maximum roof height aligned with the point of maximum roof camber on the 'Template',which is at 0-% aft-body.
From there back,the 'boat tail' aft-body is divided into 10-sections of 10% aft-body length each.
It looks like your Matrix already occupies about 24% of that length.
Dr.Kamm and others recommended that cars be as long as to allow their wake to be only 50% of frontal area.
On the template,the frontal area occurs at 0-%, and 50 % frontal area occurs at 54% of aft-body length,where Kamm would recommend the truncation to occur.
If you extend the height of your ground clearance back,you'll see that you couldn't actually do the whole 100%,more like 90%.
Then,if you were going to chop some more away to allow for tailights and license plate,then only about 80% is useful.
Removing the last 20% increases drag only from Cd 0.13,to Cd 0.133,statistically insignificant.