BMW E9X M3 GIAC Performance ECU Software UpgradeGIAC software helps you extract the maximum potential from your E9X M3. Power gains were measured at: 24 wheel horsepower and 7 wheel torque on 91 octane (with air filter upgrade) 34 wheel horsepower and 16 wheel torque on 91 octane (with air filter and x pipe) Estimated crankshaft power output of 443 brake horsepower and 303 brake torque on 91 octane (with air filter upgrade) Estimated crankshaft power output of 455 brake horsepower and 314 brake