373's/Predator

Did it come with a book? should tell you how to change it..

All you do is go into the custom tune menu and find the adjustment for wheels and tires. then you simply adjust the bar to the number closest to the ratio you have. it says right in the instruction book how to do it. or if you've lost the book, you can download it at www.diablosport.com

Have the book, says how to do it once you get into the proper screen. Didn't want to push the wrong thing. Maybe it's not that easy to mess something up. Thanks for the info.