2005 Mustang S-trim problems

A friend of mine has a 2005 Mustang with a new Vortech system on it. The car is an automatic car with rear gear mod & drag radials (275/50/15) The problem is the drive by wire is really messed up under boost conditions. Seems the throtle wants to close durring a shift to next higher gear. This will dump boost and the car slows way down. Is there no way to keep the throtle open durring a shift under boost conditions? I'm thinking some of these claims of big power on 05's are BS. Any ideas are appreciated.:confused:

You must have a tuner (SCT) to control the throttle blade system. Been dealing with that and the fuel pump on a customers car shuts down so we are now figuring that out also.