Quote:
Originally Posted by Tesla
I have read that the wheel arches develop pressure at the top and need to be ducted, and even more when I do the covers.
Will this help fill the vacuum at the back and reduce drag?
|
The 1st generation Honda Insight, Cd 0.25 has factory rear fender skirts, and no special ducting from within the wheel wells.
Of course, every vehicle is different. I do recall reading that Mercedes ducted the rear wheel well area through to the edge of the rear tail lights, claiming the pressurized air promoted cleaner flow separation & drag reduction. (If you search, you'll find a thread about it here.)
But the improvement is going to be so minor, and so difficult to test, I'd be concerned with the lower hanging fruit first.
Quote:
|
I went for a drive and it feels better, but you know how placebo works.
|
Good point. Glad you're aware of that!
Quote:
|
if I taper the new one in from the wheel arch to skimm the body corner, it comes in at about 15 degrees and taking that line back about 6" should take about 8" out of the width at that point.
|
A 15 degrees change is probably too abrupt a transition to maintain attached flow. If you've seen the streamlining/teardrop template you can visualize how much maximum transition is possible before heading off toward airflow separation (and wasted body work time/effort past that point).
Quote:
|
If I duct into the lower portion of the rear end, what effect will there be on the rear drag?
|
I don't believe it's possible to even guesstimate about this one.