As high tech as DISI is, it is not the reason the Mazdaspeed3 has so much power and torque. Credit the Warner-Hitachi K04 turbo; the same unit found in the Mazdaspeed6. For a stock turbo, it has a lot of trick features, including a compressor stage supported by a full-floating, journal-bearing, water-cooled center section. Power balance is supported by a 79 trim 50mm turbine stage with an Inconel shaft-wheel mated to a 16.5mm A/R Niresist iron turbine housing. Maximum turbine speed is over 165,000rpm with a peak exhaust gas temperature in excess of 990 degrees Celsius