it really depends on what fuel you are going to run. If you run good high octane race fuel say good ole c12, you can map in 10 degrees, which is as high as the ignition module will let you go. pump gas we have run 6 degrees with no issues, and you could prolly get away with 8 or even 10 but no need to push it that much, unless the check book is weighing your pocket down. The motors are really tamed down as far as that goes. But it all is relative how how good your exhaust and intake flows. We have thrown ignition advance at a bike with very very little increase in power.