[ChazInMT]

Originally Posted by drmiller100

on the pics of the boattail, the second pic shows the bottom angle is much too steep. The air is not staying attached to the bottom. Study after study has reported 10 degrees is about maximum on the bottom of the car - not as much energy below the car.

As to the previous study, I'm having troubles keeping up. First we were talking about angles of sides to top, and the study provided shows sharp angles don't hurt anything. Then we were talking about kammback to body, and study provided shows angles there don't matter much up to at least 18 degrees. Then we were talking about angles of kammback, and study showed 18 degrees stays attached.

Then we got switched around to a specific case which showed there is a possibility too much angle doesn't have the correct trailing vortices, and if you have STRONG vortices, in just the right place, you can have less overall drag because the vortices fill teh wake better. Predicting the lateral vortices is more than I can do off the top of my head, but the fact is they exist, and the fact is if you do things just right, you can use them.

Lateral Vortices are bad in almost every case.