Hello All! I've got a COBB stage II kit installed, and a Corsa exhaust and turbo spacers. I can get 91oct fuel all over the place, but I'd like to be able to run the tune file for the 93oct..... So, does anybody have any experience with octane boosters? What brand? How much to use? What octane will my fuel bump up to, and from what starting octane rating fuel, 89 or 91? Any help and advise is appreciated. Thanks to all in advance!