you run out of NOS or don't have the bottle open in NOS mode, the engine will bog becaues of the extra fuel with no NOS. With a 60 shot you can definately feel it in low rpms when it kicks in. On street tires with my 285/30/18's Michelin Pilots, it just spun them when the nos kicked in. On the dyno I got 500ft. lbs of torque in low RPM with just the 60 shot on a stock turbo engine. It is amazing stuff.