I just tried the SA controller and Turbo in my real CV and it's no-go, but it makes some sense.
The default configuration is Expansion Module #2 (steering wheel and gas pedal) plugged into Port #1 (for analog steering control) and a standard controller plugged into Port #2 (stick for shifting and keypad for game selection).
Using a single SA controller in Port #1, the only thing that worked was the gas pedal by pressing BOTH the SA controller's top two buttons, so that's likely the signal sent from the Expansion Module #2's actual gas pedal. The keypad did nothing when I tried to select a game (the game could be programmed to read only the keypad from Port #2, which makes sense) and the dial and joysticks did nothing (I thought the dial might at least steer, but nope...admittedly I didn't spin it a ton like you did, dualcam
...the actual steering controller must be much more precise?).
The dial inside my SA controller is a disc with two magnets on it perpendicular to two wires. I believe the induction of those magnets over the wires sends the signal that the dial has been rotated. I'm trying to open my steering wheel controller (unsuccessfully...damn stripped screw, but I'll keep working on it) to find out how it sends a signal, but I'm sure it's either something like a potentiometer like Atari paddles or it digitally reports its position like the Atari steering controller.
EDIT: found a schematics page for some CV stuff: http://www.theadamre...com/schematics/
Edited by Voch, Tue Apr 24, 2012 4:15 PM.