Quote:
Originally Posted by christofoo
Hmm, I was looking at the other graphic, i.e. #146, and thinking I should have gone from .315 stock to .235 total, or 25% reduction... it would be interesting if the roof-to-rear-window-curvature turned out to be the wild-card.
To be clear, it looks like my Cd with the gap filled may be around 0.4 (still preliminary, yes it has been revised upwards since my previous coast-down report - I owe you details).
The Aero Hitch Box has way more storage volume, and on this last trip it was 100% used (to my dismay  ). |
I believe that when you can do an airtight integration between car and box,that the performance you're looking for will rear it's pretty head.
You've got the equivalent of Walter Lay's Cd 0.12 'pumpkin seed',but with the bum windshield out front which wouldn't allow below Cd 0.24.
The tail can only be effective it it has a really clean 'source' or 'onset' flow as Hucho describes it in his chapter on CFD.
The kinetic energy which would otherwise be converted to pressure regain for the wake is being converted to useless heat as the air tumbles into turbulence between the roof top and front of box.Sides as well.
When these areas are sealed,only then can the box perform as tunnel studies would predict.
You're very close!
And 39+,at up to 73 mph sounds pretty tasty in its own right.
