Back in January we were reporting about G Power working on a performance package that would enable the limited edition BMW M3 GTS to develop 6XX HP.
Well we now know the numbers behind the ‘X’s as G Power has officially announced that their specially adapted supercharger system for the BMW M3 GTS raises the output from 450 HP to 635 HP and 630 Nm of torque. 
Apart from the ASA superchargers and the remapped ECU applied to the high-revving 4.4-litre V8, the G Power BMW M3 GTS has also received a lightweight, titanium exhaust equipped with 100 cpsi metal catalytic converters and for those who want to go extreme as far as saving weight, the German tuner offers the choice of ordering the airbox belonging to the supercharger system in lightweight carbon fiber.
So what does a 175 HP output increase mean for the BMW M3 GTS ? According to G Power their upgraded model can sprint from 0 to 100 Km/h in 4.2 seconds (0 to 200 Km/h in 11.9 seconds) and can also reach a top speed of 323 Km/h. The G Power BMW M3 GTS equipped with MICHELIN standard street tires was also able to lap the Hockenheim circuit in 1.11,8 min, and further modifications to the car’s suspension and wheels were not necessary.  

Source: G-Power