Computer chip and ET's

[Technick]

A stock 5.0 will pick up about 22-25 H.P with a Superchips brand chip, depending on the year 5.0. I know this to be true because I used to be distributor of theirs and we did back to back dyno test with and without chip on a stock 93 5.0 just to see if the claims were correct. They seem to be within about 10% plus or minus of claimed depending on car.
On a Power Stroke Turbo/Diesel the chip alone can be good for 50-90 ft/lbs torque! This may be the case to a lesser extent on the WRX if the computer controls the wastegate. This allowes the turbo to build more boost and the computer adds more fuel to off-set the increase in boost pressure, let alone timming changes.
So it MAY be possible for the WRX to see that kind of increase in performance.