Sixth generation (1995–2000) – EK2, EK3, EK4, EK5, EK9, EJ6, EJ7, EJ8, EJ9, EM1
Using the forum's "Aero-Template" as a starting point.
Aerodynamics by George Kachadoorian | Photobucket
The first Civic Si coupe EM1 was introduced in 1999 until 2000.
My guess is that anything beneath the red line and in the green area will have little affect.
On second thought, something right up to that line like the early Ducktail on a Porsche 911 (1973-1974 RS) should reduce lift by getting flow closer to the template.
What I meant to say is the wing on the red car is not in the flow and does little.
should be placed above the green area for maximum affect.
should be placed at or below the green area for maximum benefit.
The biggest challenge in conversation is in discussing spoilers which look like wings but are really spoilers as they allow no air flow underneath the alleged wing.
This has been a big problem in the forum before.
There may be little discovery of many new forms for these cars as they are the most riced out in history with aftermarket accessories. Could be a public service testing what's currently out there. And then from that data base create your new form/shape.
If anyone can find a better side view please post it, I had a devil of a time just finding this one.