You won't be making an economy map per-se, you will be modifying the Stage 2 +SF map. Open that map in ATR (doesn't matter which wastegate map it is - SLWG that you used last will be fine). Go to Boost Control Tables -> Wastegate Duty and select the "Wastegate Duty Cycles (High)" table. Select the entire table with your mouse, hit "E" for edit, and enter 0. The entire wgdc portion of the table, should show zero. Save that map (with a unique name) and then transfer it to the AccessPORT and reflash it to the car. If all of this is done correctly, then it will show 0% "Wastegate Duty" monitor all the time, even at WOT. Get a run to high RPM (if you can do so safely) with this new map.