Evolution IX was advertised to have 280 PS . The GSR produced 400 of torque, while the RS and GT produced 407 N·m
The 2.0 L 4G63 engine has MIVEC technology (variable valve timing), and a revised turbocharger design boosting official power output at the crankshaft
RS - "rally sport", revised 5-speed, aluminium roof, gauge pack, minimal interior, LSD and a titanium-magnesium turbine
RS= (Rally Sport)
Lancer Evolution IX models: standard (Grand Sport Rally or "GSR" in some markets), RS (Rally Sport), SE (Special Edition) and MR (Mitsubishi Racing) varied slightly in their performance capabilities. Subtleties unique to each model accounted for variations in acceleration, handling and top speed. The RS excluded features standard on the standard, SE and MR models (stereo system, power windows and locks, rear wiper, rear wing, trunk lining and sound insulation). The result is a weight savings of over 60 lb (27 kg)
Although the RS is the lightest of the group, the RS did not manage to outperform the standard IX and the MR around a road course (even if only by fractions of a second). This was purported to be due to the lack of a rear wing on the RS. In a drag race, the three models are all about even. The RS model was produced for rally and racing teams who wanted a platform to build a race car from. It is stripped of all the creature comforts, and other upgrades that drive the price up for features that the race teams would not require.
Magnesium compressor and titanium turbine
Adopting magnesium instead of aluminum for the compressor wheel dramatically improves the full range of supercharging response, while improving starting and passing acceleration and reducing overall weight.