I personally have never tried that, but i do remember a while back a few people did try it and if i remember correctly, they didnt see any gains nor losses in times. I think the reasoning for that is because the computer has to adjust everytime you open and close the cutout, and while your going down the track it never actually adjusts cause it actually takes a while for it to adjust. I think thats what the verdict was, but somebody else will chime in im sure and say what the deal on that is for sure.