One of the problems I have is figuring out how to optimize various aero elements. I have studied some books and read the Aerobytes articles in Racecar Engineering. All the plans you have agree with what I've been reading. My complaint is that I don't have any numbers or sense of the level of impact that each element of aero has in the overall scheme. For example, the height of the wing. 4" above roof height is quite high whereas testing various heights and setbacks show that there is a pumping action that assists the underside aero with a lower and/or further set back wing. How does one without lots of testing determine even that one variable of wing height? What amateurs like us need is some feel for the level of impact each proposed change can make. One option I debated was getting into the CFD, which requires a fair amount of computer power/time, CAD experience, and expertise that comes from trial and error. But I already sit in front of a computer too much now.This is all what I would lump into "phase 2" of my project. Once the powertrain is all sorted and reliable, I'll start on aero modifications.
The rake will be increased to ~0.5 to 0.7 degrees relative to the ground plane. This requires a 20-30mm ride height difference front to rear. The front will be around 100mm, as measured per the normal techniques.
I have a swan neck mount wing from DJ Race Cars waiting to be installed. It's a SM132 element, 300mm chord, 1640mm width. The wing will have multiple mounting positions, again depending on time trials rules... but in general, the wing will be mounted 6" above the roof line. I may augment the wing with a second element (not class legal for most of the time trial classes) for times when I just want to achieve a maximum downforce configuration.
What I would like is an expert that could tell me for each element on a list of proposed changes whether that change would make a 20%, 10%, 1%, -10% difference. That would give me a sense of whether it was worth trying the change. Another option is to build three wing mounts and then do some testing of each with perhaps suspension height logging in order to determine the effect of each change. Repeat for each proposed change. That would be a lot of fabrication and testing.