Very interesting... I'll have to play around with some of these power resistors I have laying about.
I have heard about a "Shift Kit" device, mostly for SVXs, that, depending on throttle (via Vacuum switch), disconnects the Dropping Resistor...so when the throttle is pressed to about 1/3, the switch opens and disconnects the resistor.
I wonder if a hybrid of the two methods would be best...a throttle activated switch that would put a, say, 15ohm resistor in series with the stock 10ohm? Or maybe replace the stock resistor with a higher value, and when the throttle is closed, switch a resistor in parrallel... (Like a 20ohm stock, and a 20ohm switched)
Or get really fancy and rig some kind of solid state voltage control, perhaps with some sort of FET, perhaps controlled by the TPS itself.
Oh here is the site:
http://www.smallcar.com/svx/tsk.htm
(Oh, one question though: Where is the resistor on a 97 Impreza 4EAT?)