The world of Mustang tuning is an extremely large and confusing place, but Stage 3 Motorsports is here to help you navigate it. Many Mustang performance parts require some sort of computer recalibration in order to prevent engine damage and get the most power out of your accessories. Our best selling product is the SCT X-Calibrator 3 handheld tuner, preloaded with a Stage 3 Custom tune that incorporates all of your applicable performance parts into a comprehensive PCM calibration. Stage 3's custom tuning also qualifies you for our Loyalty Tunes Programs on selected tunable parts purchased from Stage 3 Motorsports.