So what is the best BMW 335I N54 ECU flash to get? The numbers say it all right here. This customers stock 2008 N54 BMW 335I did a baseline dyno on our Mustang AWD dyno in rear wheel drive rocking 91 octane to 340 horsepower and 347ft/lbs of torque. Flashing the car to the tuned VR flash file right after, the car then ran 401rwhp with 426ft/lbs of torque. Those are some good GAINS of 61hp and 79ft/lbs of torque. You could just feel the turbos spooling up faster and delivering that much more power once the car was flashed. Check out the pics, dyno sheet, and short video below. You can see all our VR Tuned ECU Flash Products here.