|
That^.
Unfortunately, despite its complication coast down testing is still probably the most viable means of aerodynamic testing for enthusiasts like us. The instructable is a very approximated version, so it will only give you a general idea of drag coefficient and rolling resistance coefficient. Some things you could do to improve accuracy:
-following SAE J1263, do it on a day with wind speeds <10 mph and 10 runs total (5 in each direction) for any one configuration
-take a photo of your car from a distance and get an accurate cross-sectional area measurement rather than estimating
-weigh it on a truck scale and get a reasonably accurate curb weight rather than estimating
-use as flat a road as you can find, throw out any runs with traffic interference and redo them
|