Quote:
Originally Posted by Sven7
I don't see anyone proving their theory. Everyone says air catches in the bumper because they don't know about the aero template type things. There's no way the airflow is making a 30* turn upward after the rear axle to catch on the bumper. I'll bet you they're just adding to the turbulent mess down there.
Still, if someone can find ABA or wind tunnel calibrated results I'm open to seeing them. I'm just not yet convinced by street racer logic. If it really worked wouldn't "speed holes" be in the "65+ efficiency mods" in the header of this website? Perhaps they haven't been proven to work...  |
Subaru published an SAE Paper on the development of their Cd 0.29 XT sport coupe in 1986.
Lowering the bottom of the rear bumper,and floor of the trunk even with the belly of the car was one of their modifications to achieve lower drag.
Without the air-tightness of the bumper facia,their efforts would be scuttled.
Now if you want to run ductwork through this region with high static pressure,electric tube-axial fans,down to the belly diffuser,well then you're going to see an improvement up to a certain velocity,as Ferrari is demonstrating with their 599XX racer.
But in a 'passive' context,one should be rewarded only with higher drag.
