In 2003 Steeda introduced the Q400, based on the Mustang GT with an advertised 400 hp (298 kW). The 4.6L V8 in the Q400 was modified with a Vortech (or Paxton) centrifugal supercharger, K&N Filter, Ford Racing Performance Parts (FRPP) throttle body, and an HD aluminum radiator. Fuel is supplied via twin Bosch pumps, and Steeda-spec Borla stainless pipes and mufflers. "Motor Trend" magazine performed a dynamometer test on the Q400. Their Q400 had produced 425 hp (317 kW) from the rear wheels, and 450 hp (335 kW) from the flywheel.