Rick

In a "drive by wire" system an electric motor moves the throttle plate instead of a complicated series of rods and pivot points. The motor moves the throttle arm instead of your foot - please correct me if I'm wrong here but the actual fuel control and governor are the same mechanical systems that have been in use for decades.
The amount of fuel that is injected for a given movement of the throttle arm is not effected at all by the a chip. UNLESS maybe the chip alters the characteristics of the throttle system so that a smaller push on the accelerator is translated into more movement of the throttle actuator. This would make the car seem faster.

At any rate I don't think I'd to the manufacturer for performance data. I'm sure they will tell you it will run 14 second quarters with a new chip.

Tim