It's a racing thing.... You put on the brake, flip the line lock, heat the tires with just the front brakes on. Then you are 'good to go' with hot sticky tires....
Is your line lock switch on the shifter handle? Mine is, and i dont like it. My n2o "button" switch is on LH side of strg whl. Think'n of moving L.L. switch to RH side of whl.