Quote:
Originally Posted by freebeard
The angle is only one aspect. Generally you want a diverging duct, details subject to testing and verification. |
This is the chart I used for my decisions. I made the "b" type diffuser, no strakes, and 4° for zero lift and the best drag according to the model. Of course, I do not know for sure that my car gets the benefits described because I have no way to test and confirm. But given that my previous arrangement was a fully open back end in which the inside of the bumper cover was practically a parachute in the flow, I suspect I am ok. My FE on the freeway is pretty great (60s and 70s steady cruising at 60 mph on the flats). Someday I might get to test it, but that ain't now.