Quote:
Originally Posted by nathan01xl
I washed my truck today and noticed that my tailgate was the dirtiest part of my vehicle. I think this is a bad sign for aerodynamics, and indicates that my airflow is not detaching cleanly at the rear. I have a tonneau cover and want to try extending it about 6" either straight back or with a small angle.
Any advice for the angle of such a spoiler?
This is a rough idea of what I have in mind.
Not my truck but the same cover I have. |
The base pressure of your wake is determined by the pressure at the line of separation,top,sides,and bottom.
An upper spoiler will do nothing to lower this vacuum behind the tailgate as you've still got 'forward' separation aside,and below it.
Either a proper boat tail or box cavity is the only thing which is capable of any meaningful drag reduction.
Also,the end of the tailgate may already be in the 'ideal' position with respect to the 'roofline.' A comparison to the Aerodynamic Streamlining Template tool at the top of the Aero Forum would tell you where you are now.