Computer chip and ET's

Well you really can't compare Mustangs to turbo WRXs. You would not benefit much at all, if any, from installing an aftermarket chip on a stock 5.0. I'd imagine some type of custom chip for a stock WRX would give much greater results than a chip in a stock 5.0. As for a full second...probably not. If the chip could bump the boost up some or get rid of a stock restriction or something along those lines...than .5 sec. to 1 sec. might not be too far off...