[aerohead]

My thought would be to load the car with ballast so it has the same rake it will have when your driving.Under this condition,the air should travel level,and parallel with the ground along the underside of the pan.If you complete the pan,to get the biggest bang,you'll want to include a 2 1/2 degree "diffuser" for the rear section.---------------- By sliding an imaginary line,angled up towards the rear,at 2 1/2 degrees,you would slide the angled line forward until it intersects the same plane as your existing pan.The angle will define where the diffuser will end at the back of the car.-------------- From published data,should you exceed the 2 1/2 degrees,the flow will detach,providing zero benefit over a non-diffuser bellypan.--------------------- Your work looks great!