Plug airdam and height into the search bar and check out the threads.
For me 6 inches or 150mm is a healthy gap... i do kiss my kerb on my driveway when reversing out too fast. any lower and i'd have trouble. Scraping going foward is not so bad but backwards theres not much flex. (In my case)
I have seen brushes like that on buses, round the wheel arch, im sure its possible for a dam or skirt, or wheel arch. But aero? Not sure.
i think the consensus is as low as your lowest underbody, and a little lower in front of wheels. Many new trucks and cars have this design.
Some under body flow is ok right, then this air feeds the difuser, which reduces pressure at rear. Thats how i see it.
Many are becoming more rounded from bumper down to underbody, which makes some sence if smooth flow is desired underneath.
Also i tested out a new mpg measuring route for highway. Quite a mission! Makes me want a mpguino! 14.9 l/100km doing 100 km/h. Minus 25 C, calm day warm truck, no muffler. best yet at that speed, but the goal is to ABA test the cap. This is just a point on the graph!
Last edited by rumdog; 01-11-2017 at 10:35 PM..